Smalltalk/X Webserver

Documentation of class 'AbstractOperatingSystem':

Class: AbstractOperatingSystem

Inheritance
Description
Related information
Class protocol
Private classes
Examples

Inheritance:

   Object
   |
   +--AbstractOperatingSystem
      |
      +--UnixOperatingSystem

Package:: stx:libbasic

Category:: System-Support

Version:: rev: 1.412 date: 2019/07/23 08:22:59; user: cg; file: AbstractOperatingSystem.st directory: libbasic; module: stx stc-classLibrary: libbasic

Author:: Claus Gittinger

Description:

this class realizes services common to the supported operating systems;
typically, services which can be implemented based upon more primitive
functions, or which can be implemented in a portable way (but probably
less performant) are implemented here.

[Class variables:]
    ConcreteClass   <Class>         the real OS class

    LocaleInfo      <Dictionary>    if non nil, that is taken instead of the operating
                                    systems locale definitions (allows for overwriting
                                    these, or provide a compatible info on systems which do
                                    not support locales)

    LastErrorNumber <Integer>       the last value of errno

    OSSignals       <Array>         Array of signals to be raised for corresponding
                                    OperatingSystem signals.

    PipeFailed      <Boolean>       set if a fork (or popen) has failed;
                                    ST/X will avoid doing more forks/popens
                                    if this flag is set, for a slightly
                                    smoother operation.

    ErrorSignal     <Signal>        Parentsignal of all OS error signals.
                                    not directly raised.

                                    misc concrete error reporting signals

Related information:

    OSProcessStatus
    Filename
    Date
    Time
    ExternalStream
    FileStream
    PipeStream
    Socket

Class protocol:

OS signal constants

sigABRT: return the signal number for SIGABRT - 0 if not supported by OS
(the numeric value is not the same across unix-systems)
sigALRM: return the signal number for SIGALRM - 0 if not supported
(the numeric value is not the same across unix-systems)
sigBREAK: return the signal number for SIGBREAK - 0 if not supported.
This is an MSDOS specific signal
sigBUS: return the signal number for SIGBUS - 0 if not supported
(the numeric value is not the same across unix-systems)
sigCHLD: return the signal number for SIGCHLD - 0 if not supported
(the numeric value is not the same across unix-systems)
sigCONT: return the signal number for SIGCONT - 0 if not supported
(the numeric value is not the same across unix-systems)
sigDANGER: return the signal number for SIGDANGER - 0 if not supported
(seems to be an AIX special)
sigEMT: return the signal number for SIGEMT - 0 if not supported by OS
(the numeric value is not the same across unix-systems)
sigFP: return the signal number for SIGFP - 0 if not supported by OS
(the numeric value is not the same across unix-systems)
sigGRANT: return the signal number for SIGGRANT - 0 if not supported
(seems to be an AIX special)
sigHUP: return the signal number for SIGHUP
(the numeric value is not the same across unix-systems)
sigILL: return the signal number for SIGILL - 0 if not supported by OS
(the numeric value is not the same across unix-systems)
sigINT: return the signal number for SIGINT
(the numeric value is not the same across unix-systems)
sigIO: return the signal number for SIGIO - 0 if not supported
(the numeric value is not the same across unix-systems)
sigIOT: return the signal number for SIGIOT - 0 if not supported by OS
(the numeric value is not the same across unix-systems)
sigKILL: return the signal number for SIGKILL
(the numeric value is not the same across unix-systems)
sigLOST: return the signal number for SIGLOST - 0 if not supported
(the numeric value is not the same across unix-systems)
sigMIGRATE: return the signal number for SIGMIGRATE - 0 if not supported
(seems to be an AIX special)
sigMSG: return the signal number for SIGMSG - 0 if not supported
(seems to be an AIX special)
sigPIPE: return the signal number for SIGPIPE - 0 if not supported
(the numeric value is not the same across unix-systems)
sigPOLL: return the signal number for SIGPOLL - 0 if not supported
(the numeric value is not the same across unix-systems)
sigPRE: return the signal number for SIGPRE - 0 if not supported
(seems to be an AIX special)
sigPROF: return the signal number for SIGPROF - 0 if not supported
(the numeric value is not the same across unix-systems)
sigPWR: return the signal number for SIGPWR - 0 if not supported
(not available on all systems)
sigQUIT: return the signal number for SIGQUIT
(the numeric value is not the same across unix-systems)
sigRETRACT: return the signal number for SIGRETRACT - 0 if not supported
(seems to be an AIX special)
sigSAK: return the signal number for SIGSAK - 0 if not supported
(seems to be an AIX special)
sigSEGV: return the signal number for SIGSEGV - 0 if not supported
(the numeric value is not the same across unix-systems)
sigSOUND: return the signal number for SIGSOUND - 0 if not supported
(seems to be an AIX special)
sigSTOP: return the signal number for SIGSTOP - 0 if not supported
(the numeric value is not the same across unix-systems)
sigSYS: return the signal number for SIGSYS - 0 if not supported
(the numeric value is not the same across unix-systems)
sigTERM: return the signal number for SIGTERM - 0 if not supported
(the numeric value is not the same across unix-systems)
sigTRAP: return the signal number for SIGTRAP - 0 if not supported by OS
(the numeric value is not the same across unix-systems)
sigTSTP: return the signal number for SIGTSTP - 0 if not supported
(the numeric value is not the same across unix-systems)
sigTTIN: return the signal number for SIGTTIN - 0 if not supported
(the numeric value is not the same across unix-systems)
sigTTOU: return the signal number for SIGTTOU - 0 if not supported
(the numeric value is not the same across unix-systems)
sigURG: return the signal number for SIGURG - 0 if not supported
(the numeric value is not the same across unix-systems)
sigUSR1: return the signal number for SIGUSR1 - 0 if not supported
(the numeric value is not the same across unix-systems)
sigUSR2: return the signal number for SIGUSR2 - 0 if not supported
(the numeric value is not the same across unix-systems)
sigVTALRM: return the signal number for SIGVTALRM - 0 if not supported
(the numeric value is not the same across unix-systems)
sigWINCH: return the signal number for SIGWINCH - 0 if not supported
(the numeric value is not the same across unix-systems)
sigXCPU: return the signal number for SIGXCPU - 0 if not supported
(the numeric value is not the same across unix-systems)
sigXFSZ: return the signal number for SIGXFSZ - 0 if not supported
(the numeric value is not the same across unix-systems)

Signal constants

accessDeniedErrorSignal: return the signal raised when a (file-) access is denied.
errorSignal: return the parent signal of all OS signals.
fileNotFoundErrorSignal: return the signal raised when a file was not found.
invalidArgumentsSignal: return the signal which is raised for invalid arguments.
Currently, this is never raised.
unsupportedOperationSignal: return the signal which is raised when an operation
is attempted, which is not supported by the OS.
(For example, creating a link on VMS or MSDOS)

change & update

update: something with: aParameter from: changedObject: Smalltalk notifies us about changes

dummy shell operations

openApplicationForDocument: aFilenameOrString operation: operationSymbol

openApplicationForDocument: aFilenameOrString operation: operationSymbol inDirectory: dir

usage example(s):

     OperatingSystem openApplicationForDocument:'cmd' operation:#open inDirectory:'c:\'

openApplicationForDocument: aFilenameOrStringOrURLString operation: operationSymbol mimeType: mimeTypeStringArgOrNil

open a windows-shell/mac finder/desktop application to present the document contained in aFilenameOrString.
This is typically used to present help-files, html documents, pdf documents etc.
operationSymbol is one of:
open
edit
explore
mimeTypeStringArgOrNil is e.g. 'text/html' or: 'application/pdf'.
If nil is passed in, the file's suffix is used to guess the mime type.

usage example(s):

     OperatingSystem openApplicationForDocument: Filename currentDirectory operation:#open
     OperatingSystem openApplicationForDocument: '..\..\doc\books\ArtOfSmalltalk\artMissing186187Fix1.pdf' asFilename operation:#open

     OperatingSystem openApplicationForDocument: 'C:\WINDOWS\Help\clipbrd.chm' asFilename operation:#open
     OperatingSystem openApplicationForDocument: 'http://www.exept.de' operation:#open mimeType:'text/html'

     OperatingSystem openApplicationForDocument: 'file:///tmp/foo' operation:#open mimeType:'text/html'
     OperatingSystem openApplicationForDocument: 'file://Makefile' operation:#open mimeType:'text/html'

openApplicationForDocument: aFilenameOrString operation: operationSymbol mimeType: mimeTypeStringArgOrNil ifNone: exceptionBlock

open a windows-shell/mac finder/desktop application to present the document contained in aFilenameOrString.
This is typically used to present help-files, html documents, pdf documents etc.
operationSymbol is one of:
open
edit
explore
mimeTypeStringArgOrNil is e.g. 'text/html' or: 'application/pdf';
if nil is passed in, the file's suffix is used to guess it.

openApplicationForDocument: aFilenameOrString operation: operationSymbol mimeType: mimeTypeStringArgOrNil inDirectory: directoryStringOrFilenameOrNil

usage example(s):

     self openApplicationForDocument: Filename currentDirectory operation:#open
     self openApplicationForDocument: '..\..\doc\books\ArtOfSmalltalk\artMissing186187Fix1.pdf' asFilename operation:#open

     self openApplicationForDocument: 'C:\WINDOWS\Help\clipbrd.chm' asFilename operation:#open

openApplicationForDocument: aFilenameOrString operation: operationSymbol mimeType: mimeTypeStringArgOrNil inDirectory: directoryStringOrFilenameOrNil ifNone: exceptionBlock

error messages

clearLastErrorNumber

return the last errors number.
See also: #lastErrorSymbol and #lastErrorString.
Notice: having a single error number is a bad idea in a multithreaded
environment - this interface will change.

usage example(s):

      AbstractOperatingSystem clearLastErrorNumber

currentErrorNumber

returns the OS's last error nr (i.e. the value of errno).
Notice, that the value of this flag is only valid immediately
after the error occurred - it gets updated with every other
request to the OS.
Use lastErrorNumber - currentErrorNumber is invalidated by
many, many internal calls.

usage example(s):

      OperatingSystem currentErrorNumber

errorHolderForNumber: anInteger

return an osErrorHolder for the given error number (as returned by a system call).

** This method raises an error - it must be redefined in concrete classes **

errorNumberFor: aSymbol

given a symbolic error, return the numeric;
(i.e. errorNumberFor:#EBADF returns EBADF's value).
Use this, since error numbers are really not standard across unix systems.

errorStringForSymbol: errorSymbol

return an errorMessage for an errorSymbol
(as kept in an osErrorHolder).

usage example(s):

     OperatingSystem errorStringForSymbol:#EPERM
     OperatingSystem errorStringForSymbol:(OperatingSystem errorSymbolForNumber:4)

errorSymbolAndTextForNumber: errNr

do not use - temporary for backward compatibility.
The returned message is in english (as found in /usr/include/errno.h)
and should be replaced by a resource lookup before being presented to the user.

usage example(s):

     OperatingSystem errorSymbolAndTextForNumber:(OperatingSystem errorNumberFor:#EPERM)
     OperatingSystem errorSymbolAndTextForNumber:(OperatingSystem errorNumberFor:#EIO)
     OperatingSystem errorSymbolAndTextForNumber:(OperatingSystem errorNumberFor:#ENXIO)

errorSymbolForNumber: errNr

return a symbol for a unix errorNumber
(as returned by a system call).

usage example(s):

     OperatingSystem errorSymbolForNumber:4
     OperatingSystem errorSymbolForNumber:2
     OperatingSystem errorSymbolForNumber:11

errorTextForNumber: errNr

return a message string from a unix errorNumber
(as returned by a system call).
The returned message is in english (as found in /usr/include/errno.h)
and should be replaced by a resource lookup before being presented to the user.

usage example(s):

     OperatingSystem errorTextForNumber:4
     OperatingSystem errorTextForNumber:(OperatingSystem errorNumberFor:#EPERM)

lastErrorNumber

return the last errors number.
See also: #lastErrorSymbol and #lastErrorString.
Notice: having a single error number is a bad idea in a multithreaded
environment - this interface will change.

usage example(s):

      OperatingSystem lastErrorNumber

lastErrorString

return a message string describing the last error.
See also: #lastErrorNumber and #lastErrorSymbol.
Notice: having a single error number is a bad idea in a multithreaded
environment - this interface will change.

usage example(s):

     OperatingSystem lastErrorString

lastErrorSymbol

return a symbol (such as #EBADF or #EACCESS) describing the last error.
See also: #lastErrorNumber and #lastErrorString.
Notice: having a single error number is a bad idea in a multithreaded
environment - this interface will change.

usage example(s):

     OperatingSystem lastErrorSymbol

executing OS commands-implementation

exec: aCommandPath withArguments: argArray environment: env fileDescriptors: fds fork: doFork newPgrp: newGrp inDirectory: aDirectory showWindow: showWindowBooleanOrNil

execute an OS command, return a pid.
Notice: on Unix, this id is an integer; on Windows, it is a processhandle.

** This method raises an error - it must be redefined in concrete classes **

fork

fork a new (HEAVY-weight) Unix process.
Not supported with MSDOS & VMS systems.
Do not confuse this with Block>>fork, which creates
lightweight smalltalk processes. This method will return
0 to the child process, and a non-zero number (which is the childs
unix-process-id) to the parent (original) process.

In normal situations, you do not need to use this low level entry; see
#startProcess: and #executCommand: for higher level interfaces.

startProcess: aCommandString inputFrom: anExternalInStream outputTo: anExternalOutStream errorTo: anExternalErrStream auxFrom: anAuxiliaryStream environment: anEvironmentDictionary inDirectory: dir newPgrp: newPgrp showWindow: showWindowBooleanOrNil

start executing the OS command as specified by the argument, aCommandString
as a separate process; do not wait for the command to finish.
If aCommandString is a String, the commandString is passed to a shell for execution
- see the description of 'sh -c' in your UNIX manual ('cmd.com' in your MSDOS manual).
If aCommandString is an Array, the first element is the command to be executed,
and the other elements are the arguments to the command. No shell is invoked in this case.
The command gets stdIn, stdOut and stdErr assigned from the arguments;
each may be nil.
Return the processId if successful, nil otherwise.
Notice: on Unix, this id is an integer; on Windows, it is a processhandle.
Use #monitorPid:action: for synchronization and exec status return,
or #killProcess: to stop it.

usage example(s):

non-blocking (lower prio threads continue):

     |in out err pid sema|

     in := 'out' asFilename readStream.
     out := 'out2' asFilename writeStream.
     err := 'err' asFilename writeStream.

     sema := Semaphore new.
     pid := OperatingSystem startProcess:'sleep 10; grep drw' inputFrom:in outputTo:out errorTo:err.

     The following will no longer work. monitorPid has disappeared

     pid notNil ifTrue:[
         Processor monitorPid:pid action:[:osStatus | sema signal ].
     ].
     in close.
     out close.
     err close.
     sema wait.
     Transcript showCR:'finished'

usage example(s):

non-blocking (lower prio threads continue):

     |in out err pid sema|

     in := 'out' asFilename readStream.
     out := 'out2' asFilename writeStream.
     err := 'err' asFilename writeStream.

     sema := Semaphore new.
     pid := OperatingSystem startProcess:'sleep 10; grep drw' inputFrom:in outputTo:out errorTo:err.

     The following will no longer work. monitorPid has disappeared

     pid notNil ifTrue:[
         Processor monitorPid:pid action:[:OSstatus | sema signal ].
     ].
     in close.
     out close.
     err close.
     sema wait.
     Transcript showCR:'finished'

executing OS commands-public

executeCommand: aCommandString

executeCommand: aCommandString errorTo: errorStream

executeCommand: aCommandString errorTo: errorStream inDirectory: aDirectory

executeCommand: aCommandString inDirectory: aDirectory

executeCommand: aCommandString inDirectory: aDirectory onError: aBlock

executeCommand: aCommandString inDirectory: aDirectory showWindow: showWindow

executeCommand: aCommandString inputFrom: anInStream outputTo: anOutStream errorTo: anErrStream

usage example(s):

	OperatingSystem
	    executeCommand:'ls'
	    inputFrom:nil
	    outputTo:Transcript
	    errorTo:Transcript

	|s|
	s := WriteStream on:''.
	(OperatingSystem
	    executeCommand:'ls'
	    inputFrom:nil
	    outputTo:s
	    errorTo:Transcript) ifTrue:[Transcript showCR:s contents]

	OperatingSystem
	    executeCommand:'dir'
	    inputFrom:nil
	    outputTo:Transcript
	    errorTo:Transcript

	OperatingSystem
	    executeCommand:'foo'
	    inputFrom:Transcript
	    outputTo:Transcript
	    errorTo:nil

executeCommand: aCommandStringOrArray inputFrom: anInStream outputTo: anOutStream errorTo: anErrStream auxFrom: anAuxStream environment: environmentDictionary inDirectory: dirOrNil lineWise: lineWise newPgrp: newPgrp showWindow: showWindowBooleanOrNil onError: aBlock

execute the unix command specified by the argument, aCommandStringOrArray.
If aCommandString is a String, the commandString is passed to a shell for execution
- see the description of 'sh -c' in your UNIX manual ('cmd.com' in your MSDOS manual).
If aCommandString is an Array, the first element is the command to be executed,
and the other elements are the arguments to the command. No shell is invoked in this case.
Return true if successful, or the value of aBlock if not.
If not successful, aBlock is called with an OsProcessStatus
(containing the exit status) as argument.
The given in, out and err streams may be arbitrary (Smalltalk-) streams;
if any is not an external stream (which is required by the command),
extra pipes and shuffler processes are created, which stuff the data into
those internal stream(s).
Nil stream args will execute the command connected to ST/X's standard input, output or
error resp. - i.e. usually, i/o will be from/to the terminal.

Set lineWise to true, if both error and output is sent to the same stream
and you don't want lines to be mangled. Set lineWise = false to
avoid blocking on pipes.

Special for windows:
you can control (have to - sigh) if a window should be shown for the command or not.
This is the OS's H_SHOWWINDOW argument.
If you pass nil as showWindow-argument, the OS's default is used for the particular
command, which is correct most of the time: i.e. a notepad will open its window, other (non-UI)
executables will not.
However, some command-line executables show a window, even if they should not.
(and also, there seems to be an inconsistency between windows7 and newer windows: in newer,
a shell command opens a cmd-window, whereas in windows7 it did not)
In this case, pass an explicit false argument to suppress it.
This argument is ignored on Unix systems.
See examples below.

executeCommand: aCommandStringOrArray inputFrom: anInStream outputTo: anOutStream errorTo: anErrStream auxFrom: anAuxStream environment: environmentDictionary inDirectory: dirOrNil lineWise: lineWise showWindow: showWindowBooleanOrNil onError: aBlock

executeCommand: aCommandString inputFrom: anInStream outputTo: anOutStream errorTo: anErrStream auxFrom: anAuxStream inDirectory: dirOrNil lineWise: lineWise onError: aBlock

executeCommand: aCommandString inputFrom: anInStream outputTo: anOutStream errorTo: anErrStream environment: environmentOrNil inDirectory: dirOrNil lineWise: lineWise showWindow: showWindow onError: aBlock

execute the unix command specified by the argument, aCommandString.
If aCommandString is a String, the commandString is passed to a shell for execution
- see the description of 'sh -c' in your UNIX manual ('cmd.com' in your MSDOS manual).
If aCommandString is an Array, the first element is the command to be executed,
and the other elements are the arguments to the command. No shell is invoked in this case.
Return true if successful, the value from aBlock if not.
If not successful, aBlock is called with an OsProcessStatus
(containing the exit status) as argument.
The given in, out and err streams may be arbitrary (Smalltalk-) streams;
if any is not an external stream (which is required by the command),
extra pipes and shuffler processes are created, which stuff the data into
those internal stream(s).
Nil stream args will execute the command connected to ST/X's standard input, output or
error resp. - i.e. usually, i/o will be from/to the terminal

executeCommand: aCommandString inputFrom: anInStream outputTo: anOutStream errorTo: anErrStream environment: env onError: aBlock

usage example(s):

        OperatingSystem
            executeCommand:'dir'
            inputFrom:nil
            outputTo:nil
            errorTo:nil
            onError:[:status | Transcript flash]

        OperatingSystem
            executeCommand:'foo'
            inputFrom:nil
            outputTo:nil
            errorTo:nil
            onError:[:status | Transcript flash]

executeCommand: aCommandString inputFrom: anInStream outputTo: anOutStream errorTo: anErrStream environment: env showWindow: showWindow onError: aBlock

usage example(s):

        OperatingSystem
            executeCommand:'dir'
            inputFrom:nil
            outputTo:nil
            errorTo:nil
            onError:[:status | Transcript flash]

        OperatingSystem
            executeCommand:'foo'
            inputFrom:nil
            outputTo:nil
            errorTo:nil
            onError:[:status | Transcript flash]

executeCommand: aCommandString inputFrom: inputStreamOrNil outputTo: outStreamOrNil errorTo: errStreamOrNil inDirectory: aDirectory

much like #executeCommand:, but changes the current directory
for the command. Since this is OS specific, use this instead of
hardwiring any 'cd ..' command strings into your applictions.

usage example(s):

     OperatingSystem executeCommand:'tdump date.obj' inDirectory:'c:\winstx\stx\libbasic\objbc'.
     OperatingSystem executeCommand:'xxdir date.obj' inDirectory:'c:\winstx\stx\libbasic\objbc'.
     OperatingSystem executeCommand:'dir' inDirectory:'c:\'.
     OperatingSystem executeCommand:'dir'

executeCommand: aCommandString inputFrom: anInStream outputTo: anOutStream errorTo: anErrStream inDirectory: dirOrNil lineWise: lineWise onError: aBlock

executeCommand: aCommandString inputFrom: anInStream outputTo: anOutStream errorTo: anErrStream inDirectory: dirOrNil lineWise: lineWise showWindow: showWindow onError: aBlock

executeCommand: aCommandString inputFrom: anInStream outputTo: anOutStream errorTo: anErrStream inDirectory: dirOrNil onError: aBlock

execute the unix command specified by the argument, aCommandString.
If aCommandString is a String, the commandString is passed to a shell for execution
- see the description of 'sh -c' in your UNIX manual ('cmd.com' in your MSDOS manual).
If aCommandString is an Array, the first element is the command to be executed,
and the other elements are the arguments to the command. No shell is invoked in this case.
Return true if successful, the value from aBlock if not.
If not successful, aBlock is called with an OsProcessStatus
(containing the exit status) as argument.
The given in, out and err streams may be arbitrary (Smalltalk-) streams;
if any is not an external stream (which is required by the command),
extra pipes and shuffler processes are created, which stuff the data into
those internal stream(s).
Nil stream args will execute the command connected to ST/X's input, output or
error resp. - i.e. i/o will be from/to the xterminal

usage example(s):

     OperatingSystem
         executeCommand:'dir'
         inputFrom:nil
         outputTo:nil
         errorTo:nil
         inDirectory:'c:'
         onError:[:status | Transcript flash]

     OperatingSystem
         executeCommand:'foo'
         inputFrom:nil
         outputTo:nil
         errorTo:nil
         inDirectory:'/etc'
         onError:[:status | Transcript flash]

     |s|
     s := '' writeStream.
     OperatingSystem
         executeCommand:'ls -l'
         inputFrom:nil
         outputTo:s
         errorTo:nil
         onError:[:status | Transcript flash].
     Transcript showCR:s contents.

     |s|
     s := '' writeStream.
     OperatingSystem
         executeCommand:'sh foo'
         inputFrom:nil
         outputTo:s
         errorTo:s
         onError:[:status | Transcript flash].
     Transcript showCR:s contents.

executeCommand: aCommandString inputFrom: anInStream outputTo: anOutStream errorTo: anErrStream inDirectory: dir showWindow: showWindow onError: aBlock

usage example(s):

        OperatingSystem
            executeCommand:'dir'
            inputFrom:nil
            outputTo:nil
            errorTo:nil
            onError:[:status | Transcript flash]

        OperatingSystem
            executeCommand:'foo'
            inputFrom:nil
            outputTo:nil
            errorTo:nil
            onError:[:status | Transcript flash]

executeCommand: aCommandString inputFrom: anInStream outputTo: anOutStream errorTo: anErrStream onError: aBlock

usage example(s):

        OperatingSystem
            executeCommand:'dir'
            inputFrom:nil
            outputTo:nil
            errorTo:nil
            onError:[:status | Transcript flash]

        OperatingSystem
            executeCommand:'foo'
            inputFrom:nil
            outputTo:nil
            errorTo:nil
            onError:[:status | Transcript flash]

executeCommand: aCommandString inputFrom: anInStream outputTo: anOutStream errorTo: anErrStream showWindow: showWindow onError: aBlock

usage example(s):

        OperatingSystem
            executeCommand:'dir'
            inputFrom:nil
            outputTo:nil
            errorTo:nil
            onError:[:status | Transcript flash]

        OperatingSystem
            executeCommand:'foo'
            inputFrom:nil
            outputTo:nil
            errorTo:nil
            onError:[:status | Transcript flash]

executeCommand: aCommandString onError: aBlock

executeCommand: aCommandString outputTo: anOutStreamOrNil

usage example(s):

     String streamContents:[:s|OperatingSystem
	executeCommand:'ls'
	outputTo:s
     ]

usage example(s):

     String streamContents:[:s|OperatingSystem
	executeCommand:'pwd'
	outputTo:s
     ]

executeCommand: aCommandString outputTo: anOutStreamOrNil errorTo: anErrStreamOrNil

usage example(s):

     String streamContents:[:s|OperatingSystem
	executeCommand:'ls'
	outputTo:s
     ]

usage example(s):

     String streamContents:[:s|OperatingSystem
	executeCommand:'pwd'
	outputTo:s
     ]

executeCommand: aCommandString outputTo: outStreamOrNil errorTo: errStreamOrNil inDirectory: aDirectory

much like #executeCommand:, but changes the current directory
for the command. Since this is OS specific, use this instead of
hardwiring any 'cd ..' command strings into your applictions.

usage example(s):

     OperatingSystem executeCommand:'tdump date.obj' inDirectory:'c:\winstx\stx\libbasic\objbc'.
     OperatingSystem executeCommand:'xxdir date.obj' inDirectory:'c:\winstx\stx\libbasic\objbc'.
     OperatingSystem executeCommand:'dir' inDirectory:'c:\'.
     OperatingSystem executeCommand:'dir'

executeCommand: aCommandString outputTo: outStreamOrNil errorTo: errStreamOrNil inDirectory: aDirectory showWindow: showWindowBooleanOrNil

much like #executeCommand:, but changes the current directory
for the command. Since this is OS specific, use this instead of
hardwiring any 'cd ..' command strings into your applictions.

Special for windows:
you can control (have to - sigh) if a window should be shown for the command or not.
This is the OS's H_SHOWWINDOW argument.
If you pass nil as showWindow-argument, the OS's default is used for the particular
command, which is correct most of the time: i.e. a notepad will open its window, other (non-UI)
executables will not.
However, some command-line executables show a window, even if they should not.
(and also, there seems to be an inconsistency between windows7 and newer windows: in newer,
a shell command opens a cmd-window, whereas in windows7 it did not)
In this case, pass an explicit false argument to suppress it.
This argument is ignored on Unix systems.
See examples below.

usage example(s):

     OperatingSystem executeCommand:'tdump date.obj' inDirectory:'c:\winstx\stx\libbasic\objbc'.
     OperatingSystem executeCommand:'xxdir date.obj' inDirectory:'c:\winstx\stx\libbasic\objbc'.
     OperatingSystem executeCommand:'dir' inDirectory:'c:\'.
     OperatingSystem executeCommand:'dir'

executeCommand: aCommandString outputTo: outStreamOrNil inDirectory: aDirectory

much like #executeCommand:, but changes the current directory
for the command. Since this is OS specific, use this instead of
hardwiring any 'cd ..' command strings into your applictions.

usage example(s):

     OperatingSystem executeCommand:'tdump date.obj' inDirectory:'c:\winstx\stx\libbasic\objbc'.
     OperatingSystem executeCommand:'xxdir date.obj' inDirectory:'c:\winstx\stx\libbasic\objbc'.
     OperatingSystem executeCommand:'dir' inDirectory:'c:\'.
     OperatingSystem executeCommand:'dir'

executeCommand: aCommandString showWindow: aBooleanOrNil

execute the OS command specified by the argument, aCommandString.
If aCommandString is a String, the commandString is passed to a shell for execution
- see the description of 'sh -c' in your UNIX manual ('cmd.com' in your MSDOS manual).
If aCommandString is an Array, the first element is the command to be executed,
and the other elements are the arguments to the command.
No shell is invoked in this case.
This blocks the current thread until the command has finished.
Return true if successful, false otherwise.

Special for windows:
you can control (have to - sigh) if a window should be shown for the command or not.
This is the OS's H_SHOWWINDOW argument.
If you pass nil as showWindow-argument, the OS's default is used for the particular
command, which is correct most of the time: i.e. a notepad will open its window, other (non-UI)
executables will not.
However, some command-line executables show a window, even if they should not.
(and also, there seems to be an inconsistency between windows7 and newer windows: in newer,
a shell command opens a cmd-window, whereas in windows7 it did not)
In this case, pass an explicit false argument to suppress it.
This argument is ignored on Unix systems.
See examples below.

getCommandOutputFrom: aCommand

execute a simple command (such as 'hostname') and
return the command's first line of output as a string (forget stdErr).
If the command generates multiple output lines, only the first line is returned.
If the command does not generate any output, an empty string is returned;
if the command fails, nil is returned.

usage example(s):

     OperatingSystem getCommandOutputFrom:'hostname'
     OperatingSystem getCommandOutputFrom:'pwd'
     OperatingSystem getCommandOutputFrom:'sleep 1'
     OperatingSystem getCommandOutputFrom:'foo'

getCommandOutputFrom: aCommand maxNumberOfLines: numLinesOrNil errorDisposition: errorDisposition

execute a simple command (such as 'ls') and
return the command's output as a collection of strings,
but only up to the given number of lines (if non-nil).
If the command generates more output, only the first nLines are returned
(but the command is allowed to finish execution).
If the command does not generate any output, an empty string is returned;
if the command fails, nil is returned.
errorDisposition controls where the stdErr output should go,
and may be one of #discard, #inline or #stderr (default).
#discard causes stderr to be discarded (/dev/null),
#inline causes it to be written to smalltalk's own stdout and
#stderr causes it to be written to smalltalk's own stderr.
nil is treated like #stderr

usage example(s):

     OperatingSystem getCommandOutputFrom:'ls' maxNumberOfLines:1
     OperatingSystem getCommandOutputFrom:'ls' maxNumberOfLines:10
     OperatingSystem getCommandOutputFrom:'ls' maxNumberOfLines:nil
     OperatingSystem getCommandOutputFrom:'foo' maxNumberOfLines:nil

getFullCommandOutputFrom: aCommand

execute a command and
return the command's output as a collection of strings (ignoring stdErr).
If the command does not generate any output, an empty string is returned;
if the command fails, nil is returned.

usage example(s):

     OperatingSystem getFullCommandOutputFrom:'mt status'

executing OS commands-queries

canExecuteCommand: aCommandString

return true, if the OS can execute aCommand.
For now, this only works with UNIX.

usage example(s):

     OperatingSystem canExecuteCommand:'fooBar'
     OperatingSystem canExecuteCommand:'ls'
     OperatingSystem canExecuteCommand:'cvs'
     OperatingSystem canExecuteCommand:'diff'
     OperatingSystem canExecuteCommand:'cvs.exe'
     OperatingSystem canExecuteCommand:'hg'
     OperatingSystem pathOfCommand:'hg'

commandAndArgsForOSCommand: aCommandString

get a shell and shell arguments for command execution

** This method raises an error - it must be redefined in concrete classes **

commandNeedsShowWindowFlag: cmd

this is a windows speciality.
Check against the set of commands which need the showWindow flag.

executableFileExtensions

return a collection of extensions for executable program files.
Only req'd for msdos & vms like systems ...

nameOfSTXExecutable

return the name of the running ST/X executable program.
Usually, 'stx' is returned -
but may be different for standAlone apps (or winstx.exe).

usage example(s):

     OperatingSystem nameOfSTXExecutable

pathOfCommand: aCommand

find where aCommand's executable file is;
return its full pathName if there is such a command, otherwise
return nil.

** This method raises an error - it must be redefined in concrete classes **

pathOfSTXExecutable

return the full path of the running ST/X executable program.
Usually, '.../stx' is returned -
but may be different for standAlone apps (or winstx.exe).

usage example(s):

     OperatingSystem pathOfSTXExecutable

executing OS commands-wrappers

exec: aCommandPath withArguments: argArray: execute the OS command specified by the argument, aCommandPath, with
arguments in argArray (no arguments, if nil).
If successful, this method does NOT return and smalltalk is gone.
If not successful, it does return.
Can be used on UNIX with fork or on other systems to chain to another program.

** This is an obsolete interface - do not use it (it may vanish in future versions) **
exec: aCommandPath withArguments: argArray environment: env fileDescriptors: fds fork: doFork newPgrp: newGrp inDirectory: aDirectory: execute an OS command

** This is an obsolete interface - do not use it (it may vanish in future versions) **
exec: aCommandPath withArguments: argArray fileDescriptors: fileDescriptors fork: doFork newPgrp: newPgrp inDirectory: aDirectory
exec: aCommandPath withArguments: argArray fork: doFork: execute an OS command without I/O redirection.
The command reads its input and writes its output
from/to whatever terminal device ST/X was started
(typically, the terminal window)

** This is an obsolete interface - do not use it (it may vanish in future versions) **
exec: aCommandPath withArguments: argArray fork: doFork inDirectory: aDirectory: execute an OS command without I/O redirection.
The command reads its input and writes its output
from/to whatever terminal device ST/X was started
(typically, the terminal window)

** This is an obsolete interface - do not use it (it may vanish in future versions) **
exec: aCommandPath withArguments: argArray showWindow: showWindowBooleanOrNil: execute the OS command specified by the argument, aCommandPath, with
arguments in argArray (no arguments, if nil).
If successful, this method does NOT return and smalltalk is gone.
If not successful, it does return.
Can be used on UNIX with fork or on other systems to chain to another program.

** This is an obsolete interface - do not use it (it may vanish in future versions) **
startProcess: aCommandString: |pid|

pid := OperatingSystem startProcess:'sleep 2; echo 1; sleep 2; echo 2'.
(Delay forSeconds:3) wait.
OperatingSystem killProcess:pid.

** This is an obsolete interface - do not use it (it may vanish in future versions) **
startProcess: aCommandString inDirectory: aDirectory: |pid|

pid := OperatingSystem startProcess:'sleep 2; echo 1; sleep 2; echo 2'.
(Delay forSeconds:3) wait.
OperatingSystem killProcess:pid.

** This is an obsolete interface - do not use it (it may vanish in future versions) **
startProcess: aCommandString inputFrom: anExternalInStream outputTo: anExternalOutStream errorTo: anExternalErrStream
startProcess: aCommandString inputFrom: anExternalInStream outputTo: anExternalOutStream errorTo: anExternalErrStream auxFrom: anExternalAuxStreamOrNil environment: environment inDirectory: dir: Modified (format): / 19-02-2019 / 23:06:28 / Claus Gittinger

** This is an obsolete interface - do not use it (it may vanish in future versions) **
startProcess: aCommandString inputFrom: anExternalInStream outputTo: anExternalOutStream errorTo: anExternalErrStream auxFrom: anExternalAuxStreamOrNil environment: environment inDirectory: dir showWindow: showWindowBooleanOrNil: ** This is an obsolete interface - do not use it (it may vanish in future versions) **
startProcess: aCommandString inputFrom: anExternalInStream outputTo: anExternalOutStream errorTo: anExternalErrStream auxFrom: anAuxiliaryStream inDirectory: dir
startProcess: aCommandString inputFrom: anExternalInStream outputTo: anExternalOutStream errorTo: anExternalErrStream inDirectory: dir

file access

closeFd: anInteger

low level close of a filedescriptor

** This method raises an error - it must be redefined in concrete classes **

copyFromFd: inFd toFd: outFd startIndex: startIdx count: count

directly copy from one FD to another (if supported by the OS)

createDirectory: aPathName

create a new directory with name 'aPathName', which may be an absolute
path, or relative to the current directory.
Return nil if successful (or the directory existed already), an OsErrorHolder otherwise.
This is a low-level entry - use Filename protocol for compatibility.

** This method raises an error - it must be redefined in concrete classes **

createFileForReadAppend: pathName

createFileForReadWrite: pathName

open a file for reading and writing, return an os specific fileHandle.

** This method raises an error - it must be redefined in concrete classes **

createHardLinkFrom: oldPath to: newPath

link the file 'oldPath' to 'newPath'. The link will be a hard link.
Return nil if successful, an OsErrorHolder if not.

createSymbolicLinkFrom: oldPath to: newPath

make a link from the file 'oldPath' to the file 'newPath'.
The link will be a soft (symbolic) link.
Return nil if successful, an OsErrorHolder if not.

linkFile: oldPath to: newPath

link the file 'oldPath' to 'newPath'. The link will be a hard link.
Return true if successful, false if not.
This method has been renamed - it remains in existance for
backward compatibility.

** This is an obsolete interface - do not use it (it may vanish in future versions) **

openFileForAppend: pathName

open a file for appending, return an os specific fileHandle.

** This method raises an error - it must be redefined in concrete classes **

openFileForRead: pathName

open a file for reading, return an os specific fileHandle.

** This method raises an error - it must be redefined in concrete classes **

openFileForReadAppend: pathName

openFileForReadWrite: pathName

open a file for reading and writing, return an os specific fileHandle.

** This method raises an error - it must be redefined in concrete classes **

openFileForWrite: pathName

open a file for writing, return an os specific fileHandle.

** This method raises an error - it must be redefined in concrete classes **

recursiveCopyDirectory: fullPathName to: destinationPathName

copy the directory named 'fullPathName' and all contained
files/directories recursively to destinationPathName.
Return true if successful.
Here, false is returned and the caller should be prepared
for a fallBack solution.
Notice:
this is not a public interface; instead, it is used
internally by the Filename class, to try a fast copy
before doing things manually.
Please use Filename recursiveCopyTo:

usage example(s):

     OperatingSystem recursiveCopyDirectory:'.' to:'/tmp/foo'
     OperatingSystem recursiveRemoveDirectory:'/tmp/foo'

recursiveCreateDirectory: dirName

create a directory - with all parent dirs if needed.
Return nil if successful, an OsErrorHolder otherwise.
On error, a partial created tree may be left, which is not cleaned-up here.

usage example(s):

     OperatingSystem recursiveCreateDirectory:'foo/bar/baz'.
     OperatingSystem recursiveRemoveDirectory:'foo'

     OperatingSystem recursiveCreateDirectory:'k:\bla\quark'

recursiveCreateDirectory: dirName forEachCreatedDo: aOneArgBlock

create a directory - with all parent dirs if needed.
Return nil if successful, an OsErrorHolder otherwise.

For each created directory evaluate aOneArgBlock with the
filename of the created directory.

On error, a partial created tree may be left, which is not cleaned-up here.

usage example(s):

     OperatingSystem 
            recursiveCreateDirectory:'/tmp/bla/fasel/murks' 
            forEachCreatedDo:[:name| self halt].

     OperatingSystem recursiveRemoveDirectory:'/tmp/bla'.

     OperatingSystem recursiveCreateDirectory:'k:\bla\quark'

recursiveRemoveDirectory: fullPathName

remove the directory named 'fullPathName' and all contained files/directories.
Return true if successful.
Here, false is returned and the caller should be prepared
for a fallBack solution.
Notice:
this is not a public interface; instead, it is used
internally by the Filename class, to try a fast remove
before doing things manually.
Please use Filename recursiveRemoveDirectory:

usage example(s):

     OperatingSystem recursiveCreateDirectory:'foo/bar/baz'
     OperatingSystem recursiveRemoveDirectory:'foo'

removeDirectory: fullPathName

remove the directory named 'fullPathName'.
The directory must be empty and you must have appropriate access rights.
return nil if successful, an OSErrorHolder if directory is not empty or no permission.
This is a lowLevel entry - use Filename protocol for compatibility.

** This method raises an error - it must be redefined in concrete classes **

removeFile: fullPathName

remove the file named 'fullPathName'; return nil if successful, an OSErrorHolder on error.
This is a lowLevel entry - use Filename protocol for compatibility.

** This method raises an error - it must be redefined in concrete classes **

renameFile: oldPath to: newPath

rename the file 'oldPath' to 'newPath'.
Someone else has to care for the names to be correct and
correct for the OS used - therefore, this should not be called
directlt. Instead, use Filename protocol to rename; this cares for
any invalid names.
Returns nil if successful, an OsErrorHolder if not

** This method raises an error - it must be redefined in concrete classes **

sync

sync the filesystems - redefined in subclasses

syncFileSystem: handle

sync the filesystem where the file represented by handle resides

truncateFile: aPathName to: newSize

change a files size return nil on success, an OSErrorHolder on failure.
This may not be supported on all architectures.

This is a low-level entry - use Filename protocol.

** This method raises an error - it must be redefined in concrete classes **

file access rights

accessMaskFor: aSymbol

return the access bits mask for numbers as returned by
OperatingSystem>>accessModeOf:
and expected by OperatingSystem>>changeAccessModeOf:to:.
Since these numbers are OS dependent, always use the mask
(never hardcode 8rxxx into your code).

** This method raises an error - it must be redefined in concrete classes **

accessModeOf: aPathName

return a number representing access rights rwxrwxrwx for owner,
group and others. Return nil if such a file does not exist.
Notice that the returned number is OS dependent - use the
modeMasks as returned by OperatingSystem>>accessMaskFor:

usage example(s):

    (OperatingSystem accessModeOf:'/') printStringRadix:8

accessModeOfFd: aFileDescriptor

changeAccessModeOf: aPathName to: modeBits

change the access rights of aPathName to the OS dependent modeBits.
You should construct this mask using accessMaskFor, to be OS
independent. Return nil if changed,
anOSErrorHolder if such a file does not exist or change was not allowd.

** This method raises an error - it must be redefined in concrete classes **

changeAccessModeOfFd: aFileDescriptor to: modeBits

change the access rights of the file referenced by aFileDescriptor
to the OS dependent modeBits.
You should construct this mask using accessMaskFor, to be OS
independent. Return true if changed,
false if such a file does not exist or change was not allowd.

** This method raises an error - it must be redefined in concrete classes **

file locking

lockFD: aFileDescriptor shared: isSharedReadLock blocking: blockIfLocked

set a lock on the file represented by aFileDescriptor.
(such as returned by ExternalStream>>fileDescriptor).
On some systems, only advisory locks are available -
these depends on other accessors to also perform the locking operation.
If they do not, they may still access the file
(on some systems, locks are mandatory, on others, they are advisory).
The isSharedReadLock argument (if true) specifies if multiple readers
are to be allowed - if false, they are not.
On some systems, all locks are non-exclusive locks.

Returns true, if the lock was acquired, false otherwise.

Notice, that not all OS's support these locks;
on some, this may simply be a no-op.
Also notice, that some systems block the process, to wait for the lock.
This can (again: on some systems) be avoided by passing a false blockIfLocked
argument.

supportsFileLinks

return true, if the OS supports file links (hard links).
Typically, only unix returns true here.

supportsFileLocks

return true, if the OS supports file locking

usage example(s):

     OperatingSystem supportsFileLocks

supportsNonBlockingFileLocks

return true, if the OS supports nonBlocking file locking
(i.e. with immediate return instead of waiting for the lock)

usage example(s):

     OperatingSystem supportsNonBlockingFileLocks

supportsSharedLocks

return true, if the OS supports shared (i.e. multiple reader)
file locking. Assume false here - redefined in concrete classes.

supportsSymbolicLinks

return true, if the OS supports symbolic links on files/directories.
Typically, only Unix returns true here

unlockFD: aFileDescriptor

clear a file lock on the file represented by aFileDescriptor,
which was previously acquired by #lockFD:.
Return false, if the unlock failed
(which may happens when a wrong fd is passed,
no lock was set previously, or the systsem does not support locks).
Notice, that not all OS's support file locks;
on some, this may simply be a no-op.

file queries

caseSensitiveFilenames

return true, if the OS has caseSensitive file naming.
On MSDOS, this will return false;
on a real OS, we return true.
Be aware, that OSX can be configured to be either.
Also, that it actually depends on the mounted volume

** This method raises an error - it must be redefined in concrete classes **

caseSensitiveFilenamesIn: aFolderPath

return true, if the OS has caseSensitive file naming inside a folderPath.
Be aware, that it actually depends on the mounted volume,
so some concrete subclass may redefine this query.

compressPath: pathName

return the pathName compressed - that is, remove all ..-entries
and . entries. This does not always (in case of symbolic links)
return the true pathName and is therefore used as a fallback
if realPath and popen failed.

** This method raises an error - it must be redefined in concrete classes **

directoryNameOf: aPath

fileSeparator

return the character used to separate names in a path.
This character differs for MSDOS and other systems,
(but those are currently not supported - so this is some
preparation for the future)

getCurrentDirectory

get the current directory of the ST/X OS process

** This method raises an error - it must be redefined in concrete classes **

getDiskInfoOf: aDirectoryPath

return some disk info.
The amount of information returned depends upon the OS, and is
not guaranteed to be consistent across architectures.
On unix and msdos, the information returned is (at least):
freeBytes
totalBytes
Do not depend on any information being present in the returned dictionary;
users of this method should always use #at:ifAbsent:, and care for the absent case.
Nil is returned if no such information can be obtained.

usage example(s):

     OperatingSystem getDiskInfoOf:'/'
     OperatingSystem getDiskInfoOf:'.'

getDriveList

return a list of volumes in the system.
On unix, no such thing like a volume exists
- there, a syntetic list with root, home & current is returned.
On MSDOS, a list of drive letters is (eventually) returned.
On VMS, a list of volumes is (eventually) returned.

usage example(s):

        OperatingSystem getDriveList

getMountedVolumes

return info about mounted volumes.
The amount of information returned depends upon the OS, and is
not guaranteed to be consistent across architectures.
On unix, the information returned is (at least):
mountPoint - mount point
fileSystem - device or NFS-remotePath

usage example(s):

     OperatingSystem getMountedVolumes

getNullDevice

get the name of the null-device. Nil is returned if not supported

getObjectFileInfoFor: aStringOrFilename

Return an info object for a given executable or shared object
or throw an error if given file is not a valid an executable now
shared object.

The info object returned is OS-specific, however it responds to at
least
#isFor32BitArchitecture
#isFor64BitArchitecture ... returns true, if the given object is for
32bit, 64bit architecture respectively

** This method raises an error - it must be redefined in concrete classes **

getTrashDirectory

get the name of a trash folder (if the OS supports it),
or nil, if not.
Must be redefined to return non nil in concrete operating systems

idOf: aPathName

return the fileNumber (i.e. inode number) of a file.

Not all operatingSystems may provide this - on those that do not,
some dummy id will be returned.
On unix, this information can be used to check for two files being
physically identical, even if found in different directories
(i.e. if they are hardLinked).

usage example(s):

     OperatingSystem idOf:'/'

infoOf: aPathName

return some object filled with info for the file 'aPathName';
the info (for which corresponding access methods are understood by
the returned object) is:
type - a symbol giving the file's type
mode - numeric access mode
uid - owners user id
gid - owners group id
size - files size
id - files number (i.e. inode number)
accessed - last access time (as Timestamp)
modified - last modification time (as Timestamp)
statusChanged - last status change time (as Timestamp)
alternativeName - (windows only: the MSDOS name of the file)

Some of the fields may be returned as nil on systems which do not provide
all of the information.
Return nil if such a file does not exist.
For symbolic links (if supported by the OS),
the info of the pointed-to-file (i.e. the target) is returned;
use #linkInfoOf: to get info about the link itself.

** This method raises an error - it must be redefined in concrete classes **

isDirectory: aPathName

return true, if 'aPathName' is a valid directory path name.
(i.e. exists and is a directory).
This also returns true for symbolic links pointing to a directory;
if you need to check for this, use #linkInfo:.

isExecutable: aPathName

return true, if the given file is executable.
For symbolic links, the pointed-to-file is checked.

** This method raises an error - it must be redefined in concrete classes **

isMountPoint: aPathName

return true, if the given file is a mounted fileSystems mountPoint

usage example(s):

     OperatingSystem isMountPoint:'/phys/qnx'
     OperatingSystem isMountPoint:'/proc'
     OperatingSystem isMountPoint:'/'

isReadable: aPathName

return true, if the file/dir 'aPathName' is readable.
For symbolic links, the pointed-to-file is checked.

** This method raises an error - it must be redefined in concrete classes **

isSymbolicLink: aPathName

return true, if the given file is a symbolic link

usage example(s):

     OperatingSystem isSymbolicLink:'Makefile'
     OperatingSystem isSymbolicLink:'/usr/tmp'

isValidPath: aPathName

return true, if 'aPathName' is a valid path name
(i.e. the file or directory exists)

** This method raises an error - it must be redefined in concrete classes **

isWritable: aPathName

return true, if the given file is writable.
For symbolic links, the pointed-to-file is checked.

** This method raises an error - it must be redefined in concrete classes **

linkInfoOf: aPathName

return a dictionary filled with info for the file 'aPathName',
IFF aPathName is a symbolic link.
If aPathName is invalid, nil is returned.
If aPathName is NOT a symbolic link, the #infoOf: aPathname itself is returned.
(which means, that systems like VMS or MSDOS always return the info here.)

The contents of the dictionary gives info about the link itself,
on contrast to #infoOf:, which returns the info of the pointed to file
in case of a symbolic link.

** This method raises an error - it must be redefined in concrete classes **

mimeTypeForFilename: aFilename

given a filename, return a corresponding mimeType.
This is placed here, to allow for OS-specific configuration
files and/or the win32 registry to be consultet.
Returns nil if no mimeType for the given name is known.

mimeTypeForSuffix: aFileSuffix

given a file suffix, return a corresponding mimeType.
This is placed here, to allow for OS-specific configuration
files and/or the win32 registry to be consultet.
Returns nil if no mimeType for the given suffix is known.

mountPoints

return a collection of mountPoints (aka. topDirectories of mounted file systems)

parentDirectoryName

return the name used to refer to parent directories.
In MSDOS, Unix and other systems this is '..', but maybe different
for other systems.
(but those are currently not supported - so this is some
preparation for the future)

pathNameForDrive: driveName

given a drive name, return the pathname to open it as a directory.
For Windows, this is the driveName itself.
For OSX, '/Volumes' is prepended.
Other OSs might prepent the pount point (i.e. /mnt/)

pathNameOf: pathName

return the pathName of the argument, aPathString,
- that's the full pathname of the directory, starting at '/'.
This method needs the path to be valid
(i.e. all directories must exist, be readable and executable).
Notice: if symbolic links are involved, the result may look different
from what you expect.

** This method raises an error - it must be redefined in concrete classes **

primIdOf: aPathName

the actual code to return the fileNumber (i.e. inode number) of a file.

** This method raises an error - it must be redefined in concrete classes **

timeOfLastAccess: aPathName

return the time, when the file was last accessed.
For nonexistent files, nil is returned.

timeOfLastChange: aPathName

return the time, when the file was last changed.
For nonexistent files, nil is returned.

typeOf: aPathName

return the type of a file as a symbol; for nonexistent files,
nil is returned.
Notice: for symbolic links, the type of the pointed-to file is returned.

volumeNameOf: aPathString

return the volumeName of the argument, aPath
- that's the name of the volume where aPath is.
Not all OperatingSystems support/use volumes; on unix,
this always returns an empty string.

initialization

getConcreteClass: called at early startup to determine the kind of OS we are running on,
and assigning a concrete subclass of me (remember: I am abstract) to the
global 'OperatingSystem'.
Programs should never refer to any of my concrete classes directly, as
they may not (will not) be present when ST/X is executed under anther OS.
initResources: allow for ResourcePack class to be missing (non-GUI smalltalks)
initialize: initialize the class
initializeConcreteClass

interprocess communication

createCOMFileForVMSCommand: aCommandString in: aDirectory: this is only implemented/required for VMS systems, to execute commands
createMailBox: this is only implemented/required for VMS systems, to emulate pipes
destroyMailBox: mbx: this is only implemented/required for VMS systems, to emulate pipes
mailBoxNameOf: mbx: this is only implemented/required for VMS systems, to emulate pipes
makeBidirectionalPipe: answer an array with 2 filedescriptors representing
the two ends of a bidirectional pipe - see also #makePipe

** This method raises an error - it must be redefined in concrete classes **
makePipe: answer an array with 2 filedescriptors representing
the two ends of a unidirectional pipe- see also #makeSocketPair

** This method raises an error - it must be redefined in concrete classes **
shutdownBidirectionalPipeOutput: fileDescriptor: inform the other end of the bidirectional pipe represented by fileDescriptor, that
we will send no more data to the pipe, i.e. EOF is reached

interrupts & signals

blockInterrupts

disable interrupt processing - if disabled, incoming
interrupts will be registered and handled as soon as
interrupts are reenabled by OperatingSystemclass>>unblockInterrupts.
Returns the previous blocking status i.e. true if interrupts
where already blocked. You need this information for proper
unblocking, in case of nested block/unblock calls.

defaultSignal: signalNumber

revert to the default action on arrival of a (Unix-)signal.
Do not confuse Unix signals with smalltalk signals.
WARNING: for some signals, it is no good idea to revert to default;
for example, the default for SIGINT (i.e. ^C) is to exit; while the
default for SIGQUIT (^ \) is to dump core.
Also, NOTICE that signal numbers are not portable between Unix
systems - use OperatingSystem sigXXX to get the numeric value for
a signal.

** This method raises an error - it must be redefined in concrete classes **

disableChildSignalInterrupts

disable childSignal interrupts
(SIGCHLD, if the architecture supports it).
We have to set the signal back to default, because ignoring
SIGCHLD breaks wait & co

disableIOInterruptsOn: fd

turn off IO interrupts for a filedescriptor

** This method raises an error - it must be redefined in concrete classes **

disableSignal: signalNumber

disable (Unix-) signal processing for signalNumber.
Do not confuse Unix signals with smalltalk signals.
WARNING: for some signals, it is no good idea to disable
them; for example, disabling the SIGINT signal turns off ^C
handling.
Also, NOTICE that signal numbers are not portable between Unix
systems - use OperatingSystem sigXXX to get the numeric value for
a signal.
Use only for fully debugged stand alone applications.

** This method raises an error - it must be redefined in concrete classes **

disableTimer

disable timer interrupts.
WARNING:
the system will not operate correctly with timer interrupts
disabled, because no scheduling or timeouts are possible.

** This method raises an error - it must be redefined in concrete classes **

disableUserInterrupts

disable userInterrupt processing;
when disabled, no ^C processing takes place.
WARNING:
If at all, use this only for debugged stand-alone applications, since
no exit to the debugger is possible with user interrupts disabled.
We recommend setting up a handler for the signal instead of disabling it.

enableAbortInterrupts

enable SIGABRT signal handling, and make it a regular signalInterrupt.
(the default will dump core and exit - which is not a good idea for
end-user applications ...).
After enabling, these exceptions will send the message
'signalInterrupt' to the SignalInterruptHandler object.
This is especially useful, if linked-in C-libraries call abort() ...

usage example(s):

     OperatingSystem enableAbortInterrupts

enableChildSignalInterrupts

enable child process interrupts
(SIGCHLD, if the architecture supports it).
After enabling, these signals will send the message
'childSignalInterrupt' to the ChildSignalInterruptHandler object.

enableCrashSignalInterrupts

enable powerFail signal exception interrupts (sigPWR).
After enabling, this signal will trigger the writing of a crash-image

enableFpExceptionInterrupts

enable floating point exception interrupts (if the architecture supports it).
After enabling, fpu-exceptions will send the message
'fpuExceptionInterrupt' to the FPUExceptionInterruptHandler object.

enableHardSignalInterrupts

enable hard signal exception interrupts (trap, bus error & segm. violation).
After enabling, these exceptions will send the message
'signalInterrupt' to the SignalInterruptHandler object.

enableIOInterruptsOn: fd

turn on IO interrupts for a filedescriptor

** This method raises an error - it must be redefined in concrete classes **

enableQuitInterrupts

enable quitInterrupt (usually ^\) handling, and make it a userInterrupt.
(the default will dump core and exit - which is not a good idea for
end-user applications ...)

enableSignal: signalNumber

enable (Unix-)signal processing for signalNumber.
Don't confuse Unix signals with smalltalk signals.
The signal will be delivered to one of the standard handlers
(SIGINT, SIGQUIT, etc) or to a general handler, which
sends #signalInterrupt:.

NOTICE that signal numbers are not portable between unix
systems - use OperatingSystem sigXXX to get the numeric value for
a signal.

** This method raises an error - it must be redefined in concrete classes **

enableTimer: milliSeconds

setup for a timerInterrupt, to be signalled after some (real) time.

** This method raises an error - it must be redefined in concrete classes **

enableUserInterrupts

enable userInterrupt (^C) handling;
when enabled, ^C in the terminal window will send the message
'userInterrupt' to the UserInterruptHandler object.

interruptPending

return true, if an interrupt is pending. The returned value is
invalid if interrupts are not currently blocked, since otherwise
the interrupt is usually already handled before arriving here,
or may be served while returning from here.

interruptProcess: processId

interrupt an OS process (CTRL-C).

** This method raises an error - it must be redefined in concrete classes **

interruptProcessGroup: processGroupId

interrupt an OS process group (CTRL-C).

** This method raises an error - it must be redefined in concrete classes **

interruptsBlocked

return true, if interrupt handling is currently disabled;
false otherwise.

isFatalSignal: aNumber

return true if a signal with number aNumber is a fatal signal,
i.e. some severe internal error occurred

** This method raises an error - it must be redefined in concrete classes **

killProcess: processId

kill an OS process.
The process has a no chance to do some cleanup.

WARNING: in order to avoid zombie processes (on unix),
you may have to fetch the processes exitstatus with
OperatingSystem>>getStatusOfProcess:aProcessId.

** This method raises an error - it must be redefined in concrete classes **

killProcessGroup: processGroupId

kill an OS process group.
The process has NO chance to do some cleanup.

WARNING: in order to avoid zombie processes (on unix),
you may have to fetch the processes exitstatus with
OperatingSystem>>getStatusOfProcess:aProcessId.

** This method raises an error - it must be redefined in concrete classes **

nameForSignal: aSignalNumber

for a given Unix signalnumber, return a descriptive string

usage example(s):

     OperatingSystem nameForSignal:9
     OperatingSystem nameForSignal:(OperatingSystem sigPOLL)

operatingSystemSignal: signalNumber

return the signal to be raised when an
operatingSystem-signal occurs, or nil

operatingSystemSignal: signalNumber install: aSignal

install a signal to be raised when an operatingSystem-signal occurs

sendSignal: signalNumber to: processId

send a unix signal to some process (maybe myself).
Returns false if any error occurred, true otherwise.

Do not confuse UNIX signals with Smalltalk-Signals.

** This method raises an error - it must be redefined in concrete classes **

sendSignal: signalNumber to: processId toGroup: toGroupBoolean toAll: toAllBoolean

startSpyTimer

trigger a spyInterrupt, to be signalled after some short (virtual) time.
Return true, if the spy-timerInterrupt was enabled.
This was used by the old MessageTally for profiling.
On systems, where no virtual timer is available, use the real timer
(which is of course less correct).
OBSOLETE: the new messageTally runs as a high prio process, not using
spy interrupts.

stopSpyTimer

stop spy timing - disable spy timer.
OBSOLETE: the new messageTally runs as a high prio process, not using
spy interrupts.

terminateProcess: processId

terminate a unix process.
The process has a chance to do some cleanup.

WARNING: in order to avoid zombie processes (on unix),
you may have to fetch the processes exitstatus with
OperatingSystem>>getStatusOfProcess:aProcessId.

** This method raises an error - it must be redefined in concrete classes **

terminateProcessGroup: processGroupId

terminate a unix process group.
The process has a chance to do some cleanup.

WARNING: in order to avoid zombie processes (on unix),
you may have to fetch the processes exitstatus with
OperatingSystem>>getStatusOfProcess:aProcessId.

** This method raises an error - it must be redefined in concrete classes **

unblockInterrupts

enable interrupt processing - if any interrupts are pending,
these will be handled immediately.
When unblocking interrupts, take care of nested block/unblock
calls - you must only unblock after a blockcall if they where
really not blocked before. See OperatingSystemclass>>blockInterrupts.

misc

closePid: pid

free pid resource.
Not required for Unix, but Windows requires it to release the process handle.

exit

shutdown smalltalk immediately - this method does not return.
Return 'good'-status (0) to the parent unix process.

usage example(s):

OperatingSystem exit - don't evaluate this

exit: exitCode

shutdown smalltalk immediately -
returning an exit-code to the parent unix process.

usage example(s):

OperatingSystem exit:1 - don't evaluate this

exitWithCoreDump

shutdown smalltalk immediately - dumping core.
This always returns 'bad'-status to the parent unix process.
Notice, that no cleanup is performed at all - you may have to
manually remove any tempfiles.
Use this only for debugging ST/X itself

usage example(s):

     OperatingSystem exitWithCoreDump - don't evaluate this

finishLaunching

called when the initialization setup has finished.
This is redefined for OSX, to tell the system, that the application has finished its startup phase.
OSX will stop bounding the launch icon then.
Here (for all other OS's), no special action is required, and the implementation
is therefore: intentionally left blank.

getAllProcesses

get a list of the running OS processes.
Some OperatingSystems (Windows) support this.
The default is to answer an empty list.

getVMSSymbol: aSymbolString

get a symbols value, or nil if there is none

obsolete

baseNameOf: aPath
executeCommand: aCommandString onError: aBlock inDirectory: aDirectory: OBSOLETE for backward compatibility.
execute the unix command specified by the argument, aCommandString.
The commandString is passed to a shell for execution - see the description of
'sh -c' in your UNIX manual.
Return true if successful, the value from aBlock if not.
If not successful, aBlock is called with an OsProcessStatus
(containing the exit status) as argument.

** This is an obsolete interface - do not use it (it may vanish in future versions) **

os queries

expandEnvironmentStrings: aString

expand the environmentStrings (e.g. $JAVA_HOME or ${JAVA_HOME}) in aString.
If the variable does not exist, keep the original text.
Amswer the expanded string.

** This method raises an error - it must be redefined in concrete classes **

getCCDefine

return a string which was used to identify the C-Compiler used
when STX was compiled, and which should be passed down when compiling methods.
For example, on linux, this is '__GNUC__';
on windows, this could be '__VISUALC__', '__BORLANDC__' or '__MINGW__'

** This is an obsolete interface - do not use it (it may vanish in future versions) **

getCPUDefine

return a string which was used to identify this CPU type when STX was
compiled, and which should be passed down when compiling methods.
For example, on linux, this may be '-D__x86__'; on a vax, this would be '-D__vax__'.
This is normally not of interest to 'normal' users; however, it is passed
down to the c-compiler when methods are incrementally compiled to machine code.

** This is an obsolete interface - do not use it (it may vanish in future versions) **

getCPUType

return a string giving the type of machine we're running on.
Here, the machine for which ST/X was compiled is returned
(i.e. for all x86's, the same i386 is returned).
This may normally not be of any interest to you ...

usage example(s):

     OperatingSystem getCPUType

usage example(s):

     (OperatingSystem getCPUType = 'sparc')
     and:[OperatingSystem getOSType = 'solaris']

usage example(s):

     (OperatingSystem getCPUType = 'i386')
     and:[OperatingSystem getOSType = 'solaris']

getDomainName

return the domain this host is in.
Notice:
not all systems support this; on some, 'unknown' is returned.

** This method raises an error - it must be redefined in concrete classes **

getEnvironment

get all environment variables as a key-value dictionary

** This method raises an error - it must be redefined in concrete classes **

getEnvironment: aStringOrSymbol

get an environment string

** This method raises an error - it must be redefined in concrete classes **

getHostName

return the hostname we are running on -
a fully qalified hostname at best.

Notice:
not all systems support this; on some, 'unknown' is returned.

** This method raises an error - it must be redefined in concrete classes **

getLanguage

get the LANGUAGE setting (example: de_DE.iso8859-15@euro)

getLocaleInfo

return a dictionary filled with values from the locale information;
Not all fields may be present, depending on the OS's setup and capabilities.
Possible fields are:
decimalPoint <String>

thousandsSep <String>

internationalCurrencySymbol <String>

currencySymbol <String>

monetaryDecimalPoint <String>

monetaryThousandsSeparator <String>

positiveSign <String>

negativeSign <String>

internationalFractionalDigits <Integer>

fractionalDigits <Integer>

positiveSignPrecedesCurrencySymbol <Boolean>

negativeSignPrecedesCurrencySymbol <Boolean>

positiveSignSeparatedBySpaceFromCurrencySymbol <Boolean>

negativeSignSeparatedBySpaceFromCurrencySymbol <Boolean>

positiveSignPosition <Symbol>
one of: #parenthesesAround,
#signPrecedes,
#signSuceeds,
#signPrecedesCurrencySymbol,
#signSuceedsCurrencySymbol

negativeSignPosition <like above>

it is up to the application to deal with undefined values.

Notice, that (for now), the system does not use this information;
it should be used by applications as required.

** This method raises an error - it must be redefined in concrete classes **

getNetworkAddressInfo

return a Dictionary of network interface information.
key -> name of interface
value -> a Set of network address
information for the interface - a dictionaries containing the
information about the configuration of each interface in the system.
The dictionary keys are:
#address
#netmask
#flags
#destAddress

** This method raises an error - it must be redefined in concrete classes **

getNetworkAddresses

return a dictionary with key:name of interface and
value:the network address for each interface

** This method raises an error - it must be redefined in concrete classes **

getNetworkMACAddresses

return a dictionary with key:name of interface and
value:the MAC address for each interface

** This method raises an error - it must be redefined in concrete classes **

getNetworkMACAddressesForIf: ifName

return the MAC address for interface ifName

getNumberOfProcessors

answer the number of physical processors in the system

** This method raises an error - it must be redefined in concrete classes **

getOSDefine

return a string which was used to identify this machine when stx was
compiled, and which should be passed down when compiling methods.
For example, on linux, this is '-D__linux__'.

** This is an obsolete interface - do not use it (it may vanish in future versions) **

getOSType

return a string giving the type of OS we're running on.
This can be used to adapt programs to certain environment
differences (for example: mail-lock strategy ...)

usage example(s):

     OperatingSystem getOSType

getPlatformDefine

return a string which defines the platform,
and which should be passed down when compiling methods.
For example, on all unices, this is '-DUNIX'.

** This is an obsolete interface - do not use it (it may vanish in future versions) **

getProcessId

return the (unix-)processId

** This method raises an error - it must be redefined in concrete classes **

getSystemID

if supported by the OS, return the systemID;
a unique per machine identification.
WARNING:
not all systems support this; on some, 'unknown' is returned.

usage example(s):

     OperatingSystem getSystemID

getSystemInfo

return info on the system weare running on.
If the system supports the uname system call, that info is returned;
otherwise, some simulated info is returned.

WARNING:
Do not depend on the amount and contents of the returned information, some
systems may return more/less than others. Also, the contents depends on the
OS, for example, linux returns 'ix86', while WIN32 returns 'x86'.

This method is mainly provided to augment error reports with some system
information.
(in case of system/version specific OS errors, conditional workarounds and patches
may be based upon this info).
Your application should NOT depend upon this in any way.

The returned info may (or may not) contain:
#system -> some operating system identification (irix, Linux, nt, win32s ...)
#version -> OS version (some os version identification)
#release -> OS release (3.5, 1.2.1 ...)
#node -> some host identification (hostname)
#domain -> domain name (hosts domain)
#machine -> type of machine (i586, mips ...)

usage example(s):

     OperatingSystem getSystemInfo

getSystemType

return a string giving the type of system we're running on.
This is almost the same as getOSType, but the returned string
is slightly different for some systems (i.e. iris vs. irix).
Do not depend on this - use getOSType. I don't really see a point
here ...
(except for slight differences between next/mach and other machs)

usage example(s):

     OperatingSystem getSystemType

getWindowsDirectory

internal interface - only for Windows based systems.
Return the windows directory, which, depending on the system,
may be
'\WINNT', '\WINDOWS'
or whatever.
On non-windows systems, nil is returned.

usage example(s):

     OperatingSystem getWindowsDirectory

getWindowsSystemDirectory

internal interface - only for Windows based systems.
Return the windows system directory, which, depending on the system,
may be
'\WINNT\SYSTEM32', '\WINDOWS\SYSTEM'
or whatever.
On non-windows systems, nil is returned.

usage example(s):

     OperatingSystem getWindowsSystemDirectory

hasConsole

return true, if there is some kind of console available
(i.e. for proper stdIn, stdOut and stdErr handling).
This only returns false when running under windows, and
the system is running as a pure windows application.
If false, the miniDebugger is useless and not used.

isBSDlike

return true, if the OS we're running on is a 'real' unix.

isLinuxLike

return true, if the OS we're running on is a linux.

isMAClike

return true, if running on a macOS (but not on A/UX or OS/X)

isMSDOSlike

return true, if the OS we're running on is msdos like (in contrast to unix-like).
This returns true for any of msdos, win32s, win95, winNT and os/2.

isMSWINDOWSNTlike

This returns true if running in a Windows-NT system.

isMSWINDOWSlike

return true, if running on a MS-Windows like system.
This returns true for any of win32s, win95 and winNT.

isOS2like

return true, if the OS we're running on is OS2 like.
Only returns true for a plain OS/2 system.

isOSXlike

return true, if the OS we're running on is a mac OSX like (but not A/UX or OS9).

isProcessIdPresent: pid

answer true, if a process with process id pid is present, false if not.
Raise an error, if an exception occurs

** This method raises an error - it must be redefined in concrete classes **

isUNIXlike

return true, if the OS we're running on is a unix like.

isVMSlike

return true, if the OS we're running in is VMS (or openVMS).

isVistaLike

return true, if running on a Vista (or newer) like system.
(also true for server 2008)

isWin10Like

return true, if running on a Windows10 (or newer) like system.
(also true for server 2016)

isWin7Like

return true, if running on a Windows7 (or newer) like system.

isWin8Like

return true, if running on a Windows8 (or newer) like system.
(also true for server 2012)

knownPlatformNames

return a collection of strings as possibly returned by getPlatformName.
Should be used instead of getOSType or getSystemType if multiple choice
dialogs are presented to the user.

usage example(s):

     OperatingSystem knownPlatformNames
     OperatingSystem platformName
     OperatingSystem getPlatformDefine

maxFileNameLength

return the max number of characters in a filename.
CAVEAT:
Actually, the following is somewhat wrong - some systems
support different sizes, depending on the volume.
We return a somewhat conservative number here.
Another entry, to query for volume specific max
will be added in the future.

** This method raises an error - it must be redefined in concrete classes **

maxNumberOfOpenFiles

answer the maximum number of open files for this process

** This method raises an error - it must be redefined in concrete classes **

maxPathLength

return the max number of characters in a pathName.

** This method raises an error - it must be redefined in concrete classes **

osName

return a string describing the OS platform very we're running on.
This returns #unix for all unix derivatives.
I.e. it is much less specific than getOSType or getSystemType.

usage example(s):

     OperatingSystem getSystemInfo
     OperatingSystem osName

pathSeparator

return the character which separates items in the PATH variable

** This method raises an error - it must be redefined in concrete classes **

platformDefineForPlatformName: osID

return a c-define for a particular platform (use only for makefile generation etc.)

platformName

return a string describing the OS platform very we're running on.
Except for osx, this returns #unix for all other unix derivatives.
I.e. it is much less specific than getOSType or getSystemType.

usage example(s):

     OperatingSystem knownPlatformNames
     OperatingSystem platformName

randomBytesInto: bufferOrInteger

If bufferOrInteger is a String or a ByteArray,
fill a given buffer with random bytes from the RtlGenRandom function
and answer the buffer.

If bufferOrInteger is a SmallInteger,
return this many bytes (max 4) as a SmallInteger.

Return nil on error (may raise PrimitiveFailure, too).

NOTE: This is a private interface, please use RandomGenerator!

Subclasses should implement this, if the OperatingSystem supports a random generator.

setEnvironment: aStringOrSymbol to: newValueString

set an environment variable

** This method raises an error - it must be redefined in concrete classes **

setLocaleInfo: anInfoDictionary

set the locale information; if set, this oerrides the OS's settings.
(internal in ST/X only - the OS's settings remain unaffected)
See description of fields in #getLocaleInfo.

Notice, that (for now), the system does not use this information;
it should be used by applications as required.

supportsChildInterrupts

return true, if the OS supports childProcess termination signalling
through interrupts (i.e. SIGCHILD)

usage example(s):

     OperatingSystem supportsChildInterrupts

supportsFileOwnerGroups

return true, if the OS's file system supports file
group ownership - here, we are optimistic assuming that
we are running under a real OS.
Redefined in Win32OS to return false.

supportsFileOwners

return true, if the OS's file system supports file
ownership - here, we are optimistic assuming that
we are running under a real OS.
Redefined in Win32OS to return false.

supportsIOInterrupts

return true, if the OS supports IO availability interrupts
(i.e. SIGPOLL/SIGIO).

usage example(s):

     OperatingSystem supportsIOInterrupts

supportsNonBlockingIO

return true, if the OS supports nonblocking IO.

usage example(s):

     OperatingSystem supportsNonBlockingIO

supportsSelect

return true, if the OS supports selecting on multiple
filedescriptors via select.
If false is returned, ProcessorScheduler will poll in 50ms
intervals for I/O becoming ready.

usage example(s):

     OperatingSystem supportsSelect

supportsSelectOnPipes

return true, if the OS supports selecting on pipe
filedescriptors via select.
If false is returned, ProcessorScheduler will poll in 50ms
intervals for I/O becoming ready.

usage example(s):

     OperatingSystem supportsSelectOnPipes

supportsSelectOnSockets

return true, if the OS supports selecting on socket
filedescriptors via select.
If false is returned, ProcessorScheduler will poll in 50ms
intervals for I/O becoming ready.

usage example(s):

     OperatingSystem supportsSelectOnSockets

supportsVolumes

return true, if the OS supports disk volumes.
False is returned for UNIX, true for MSDOS, VMS and OSX (which treats /Volumes as such)

path queries

decodeCommandOutput: encodedOutputLine

decode the encodedOutputLine as generated by a system command (on its stdout/stderr).
This takes care for any specific specific command encodings.

E.g. linux programs generate utf8 encoded output, so it has to be decoded.

decodePath: encodedPathName

decode the encodedPathName as returned by a system call.
E.g. linux system calls return single byte strings only,
so pathNames have to be UTF-8 encoded there.
In contrast, Win32 expects wideStrings which are already unicode(16)

decodePathOrCommandOutput: encodedPathNameOrOutputLine

decode the encodedPathNameOrOutputLine as returned by system calls or output by system commands.
This takes care for any specific OS encodings or specific command encodings.

E.g. linux system calls return single byte strings only,
so pathNames have been UTF-8 encoded.

defaultPackagePath

return a default packagePath - that's a collection of
dirnames, where ST/X searches for its package subdirs.
This method might be redefined in concrete OS's to add
OS-specific directory names.

usage example(s):

     OperatingSystem defaultPackagePath

defaultSystemPath

return a default systemPath - that's a collection of
dirnames, where ST/X searches for its files.
This method is redefined in concrete OS's to add
OS-specific directory names.

usage example(s):

	OperatingSystem defaultSystemPath

encodePath: pathName

encode the pathName for use with system calls.
E.g. linux system calls accept single byte strings only,
so the pathName has to be UTF-8 encoded, before using it in a system call.
(in contrast, Win32 expects wideStrings which are already unicode)
Here, the original string is returned;
it has to be redefined in a concrete OS, if it needs any encoding.

encodePathOrCommandInput: pathNameOrInputToAProgram

encode the pathNameOrInputToAProgram for use with system calls,
to be sent to a program, used as cmmand line argument,
or to be used as shell environment value.

E.g. linux system calls accept single byte strings only,
so the pathName has to be UTF-8 encoded, before using it in a system call.
Here, the original string is returned;
it has to be redefined in a concrete OS, if it needs any encoding

encodeTerminalOutput: aString

encode aString to be sent to a console.
E.g. linux xterm accepts unicode but expects it to be UTF8 encoded,
so output has to be encoded, before sending it
(actually, on a mac, it has to be utf8-mac encoded).
The fallback here is to use the same encoding as for system calls;
(which works currently, but who knows...)

printing support

getPrinters: return a collection of PrinterInfos

** This method raises an error - it must be redefined in concrete classes **

private

osProcessStatusClass: ** This method raises an error - it must be redefined in concrete classes **

queries

isAbstract: Return if this class is an abstract class.
True is returned here for myself only; false for subclasses.
Abstract subclasses must redefine this again.

queries-sockets

domainCodeOf: aSymbolOrInteger

return the numeric AF_xxx code of a given symbolic domain name.
Return nil for invalid or unsupported domains.
For backward compatibility, the obsolete (non-AF-prefixed) names
are still supported for a while - this support will vanish.

usage example(s):

     self domainCodeOf:#AF_INET
     self domainCodeOf:#AF_INET6
     self domainCodeOf:#AF_UNIX
     self domainCodeOf:#AF_APPLETALK
     self domainCodeOf:#AF_DECNET
     self domainCodeOf:#AF_UNSPEC
     self domainCodeOf:#AF_UTUN

usage example(s):

for backward compatibility only:
     self domainCodeOf:#inet
     self domainCodeOf:#inet6
     self domainCodeOf:#unix
     self domainCodeOf:#appletalk
     self domainCodeOf:#decnet

domainSymbolOf: anInteger

return the symbolic domainName of a given numeric AF_xxx code.
Return nil for invalid or unsupported domains.

usage example(s):

     self domainSymbolOf:(self domainCodeOf:#inet)
     self domainSymbolOf:(self domainCodeOf:#inet6)
     self domainSymbolOf:(self domainCodeOf:#unix)
     self domainSymbolOf:(self domainCodeOf:#appletalk)
     self domainSymbolOf:(self domainCodeOf:#decnet)
     self domainSymbolOf:(self domainCodeOf:#raw)
     self domainSymbolOf:(self domainCodeOf:#AF_PPP)

protocolCodeOf: aSymbolOrInteger

return the numeric IPPROTO_xxx code of a given symbolic protocol name.
Return nil for invalid or unsupported protocols.
For backward compatibility, the obsolete (non-IPPROTO-prefixed) names
are still supported for a while - this support will vanish.

usage example(s):

     self protocolCodeOf:#IPPROTO_UDP
     self protocolCodeOf:#IPPROTO_TCP

usage example(s):

for backward compatibility only:
     self protocolCodeOf:#udp
     self protocolCodeOf:#tcp

protocolSymbolOf: anInteger

return the symbolic protocolName of a given numeric IPPROTO_xxx code.
Return nil for invalid or unsupported protocols.

usage example(s):

     self protocolSymbolOf:(self protocolCodeOf:#tcp)
     self protocolSymbolOf:(self protocolCodeOf:#udp)
     self protocolSymbolOf:(self protocolCodeOf:#raw)

socketAddressSizeOfDomain: aSymbolOrInteger

Return the os-specific size of a socket address for a domain aSymbolOrInteger.
Return nil, if unknown or unsupported.

usage example(s):

     self socketAddressSizeOfDomain:#'AF_INET'
     self socketAddressSizeOfDomain:#'AF_UNIX'
     self socketAddressSizeOfDomain:#'Foo'

socketTypeCodeOf: aSymbolOrInteger

return the numeric SOCK_xxx code of a given symbolic socket type name.
Return nil for invalid or unsupported socket types.

usage example(s):

     self socketTypeCodeOf:#stream
     self socketTypeCodeOf:#datagram
     self socketTypeCodeOf:#raw

socketTypeSymbolOf: anInteger

return the symbolic typeName of a given numeric SOCK_xxx socket type code.
Return nil for invalid or unsupported socket types.

supportedProtocolFamilies

return a collection of supported protocol families.
This list specifies what the Socket class supports -
socket creation may still fail, if your system was built without it.
For backward compatibility, the returned list includes the old
(non-AF-prefixed) symbols; these will vanish.

usage example(s):

     AbstractOperatingSystem supportedProtocolFamilies

supportedSocketTypes

return the symbolic typeName of a given numeric SOCK_xxx socket type code.
Return nil for invalid or unsupported socket types.

usage example(s):

     AbstractOperatingSystem supportedSocketTypes

shared memory access

shmAttach: id address: addr flags: flags: low level entry to shmat()-system call.
Not supported on all operatingSystems
shmDetach: addr: low level entry to shmdt()-system call.
Not supported on all operatingSystems
shmGet: key size: size flags: flags: low level entry to shmget()-system call.
This is not for public use and not supported with all operatingSystems.
- use the provided wrapper class SharedExternalBytes instead.

sound & voice

bestVoiceForLanguage: lang

OS specific - to be redefined for linux, windows and OSX

canPlaySound

canSpeak

defaultVoice: voiceName

set the default voice name

usage example(s):

     self defaultVoice:'Fiona'
     self defaultVoice:'Miora'
     self defaultVoice:'Amelie'
     self defaultVoice:'Anna'
     self defaultVoice:'Alex'
     OperatingSystem voiceMapping
     OperatingSystem voiceInfo

initializeDefaultVoice

OS specific default voice setup

playSound: fileName

play a soundfile (wav)
unsupported - simply stay silent

playSound: fileName mode: modeInteger

this is an obsolete interface

speak: aString

say something in the default voice

usage example(s):

     OperatingSystem speak:'hello world'
     OperatingSystem speak:'üben üben'
     OperatingSystem speak:'üben üben' voiceName:'Anna'

speak: aString voiceName: voiceName

voiceName should be in the list of supported voices as returned by voiceInfo,
or (better and portable) one of the keys in voiceMapping.
Use nil for the default voice (which is usually the user's preference voice setting in
the operating system - eg. system preferences in OSX).
For non-existing/unknown voiceNames, the default voice will be used.

Here, looksfor one of the commands from voiceCommandSpec to be found
and call that external program for the speech generation.
Returns true if ok, false if not

voiceCommandSpec

commands to try for speech output

voiceInfo

return a list of available (OS-specific) voice names plus info.
For each available voice, a triple is returned, containing:
voiceName language_territory comment/description

the language_territory (of the form en_EN / en_US etc.) gives a hint,
for which language the voice is best used.

The fallback here returns the default list, which should be supported
by any system.

On OSX, this would look like:
#(
('default' 'en_US' 'the default system voice')

#('Agnes' 'en_US' 'Isn''t it nice to have a computer that will talk to you?')
#('Albert' 'en_US' 'I have a frog in my throat. No, I mean a real frog!')
#('Alex' 'en_US' 'Most people recognize me by my voice.')
...
#('Zarvox' 'en_US' 'That looks like a peaceful planet.')
#('Zosia' 'pl_PL' 'Witaj. Mam na imię Zosia, jestem głosem kobiecym dla języka polskiego.')
#('Zuzana' 'cs_CZ' 'Dobrý den, jmenuji se Zuzana. Jsem český hlas.')
)

voiceMapping

return a mapping from common (OS-independent) voice names
to OS-specific names or IDs.
The speak:voiceName interface will recognize both.
For portable programs, always use the OS-independent name and
let every OS xlate to its internal name.

voiceMapping: aMapping

set a mapping from common (OS-independent) voice names
to OS-specific names or IDs.
The speak:voiceName interface will recgnize both.

usage example(s):

on OSX, this could be:
        OperatingSystem voiceMapping:
            {
                'male' -> 'Alex' .
                'female' -> 'Fiona' .
                'computer' -> 'Zarvox' .
                'default' -> 'Fiona'
            }.

time and date

computeDatePartsOf: osTime for: aBlock

compute year, month and day from the OS time, osTime
and evaluate the argument, a 3-arg block with these.
Conversion is to localtime including any daylight saving adjustments.

** This is an obsolete interface - do not use it (it may vanish in future versions) **

computeOSTimeFromUTCYear: y month: m day: d hour: h minute: min second: s millisecond: millis

return the OS-dependent time for the given time and day.
The arguments are assumed to be in UTC time.

usage example(s):

     OperatingSystem computeOSTimeFromUTCYear:1970 month:1 day:1 hour:0 minute:0 second:0 millisecond:0
    invalid:
     OperatingSystem computeOSTimeFromUTCYear:1970 month:1 day:1 hour:24 minute:0 second:0 millisecond:0

computeOSTimeFromYear: y month: m day: d hour: h minute: min second: s millisecond: millis

return the OS-dependent time for the given time and day.
The arguments are assumed to be in localtime including
any daylight saving adjustings.

usage example(s):

     OperatingSystem computeOSTimeFromYear:1970 month:1 day:1 hour:0 minute:0 second:0 millisecond:0
    invalid:
     OperatingSystem computeOSTimeFromYear:1970 month:1 day:1 hour:24 minute:0 second:0 millisecond:0

computeOSTimeFromYear: y month: m day: d hour: h minute: min second: s millisecond: millis utc: utcBoolean

return the OS-dependent time for the given time and day.
If utcBoolean is true, the arguments are assumed to be in UTC Time;
otherwise in localtime including any daylight saving adjustings.

** This method raises an error - it must be redefined in concrete classes **

computeTimeAndDateFrom: osTime

given an OS-dependent time in osTime, return an Array
containing (full-) year, month, day, hour, minute and seconds,
offset to UTC, daylight savings time flag, milliseconds,
dayInYear (1..) and dayInWeek (1..).
Conversion is to localtime including any daylight saving adjustments.

usage example(s):

     OperatingSystem computeTimeAndDateFrom:0
     OperatingSystem computeTimeAndDateFrom:1011

computeTimePartsOf: osTime for: aBlock

compute hours, minutes, seconds and milliseconds from the local osTime
and evaluate the argument, a 4-arg block with these.
Conversion is to localtime including any daylight saving adjustments.

** This is an obsolete interface - do not use it (it may vanish in future versions) **

computeUTCTimeAndDateFrom: osTime

given an OS-dependent time in osTime, return an Array
containing:
(full-) year,
month, (1..)
day, (1..)
hour, (0..23)
minute (0..59)
seconds, (0..59)
offset to UTC, (seconds)
daylight savings time flag,
milliseconds, (0..999)
dayInYear (1..)
dayInWeek (1..).
Conversion is to utc.

usage example(s):

     OperatingSystem computeUTCTimeAndDateFrom:0
     OperatingSystem computeUTCTimeAndDateFrom:1011

computeUTCTimePartsOf: osTime for: aBlock

compute hours, minutes, seconds and milliseconds from the osTime
and evaluate the argument, a 4-arg block with these.
Conversion is to UTC.

** This is an obsolete interface - do not use it (it may vanish in future versions) **

epochEndOSTime

private interface for timestamp to ask the OS what the maximum time
(in milliseconds since the Unix epoch, 1.1.1970) is.
32bit Unix systems will return 0x7FFFFFFF here; other OS's may return a higher number to indicate,
that they can deal with timestamps after 2038 (especially: win32 will do so).
Notice that timestamp is prepared to compensate for any OS limitation by computing the timeInfo
components itself.
So it is usually (except for a little performance) no problem to return a range too small here.

epochStartOSTime

private interface for timestamp to ask the OS what the minimum time
(in milliseconds since the Unix epoch, 1.1.1970) is.
Unix systems will return 0 here; other OS's may return a negative number to indicate,
that they can deal with timestamps before 1970 (especially: win32 will do so).
Notice that timestamp is prepared to compensate for any OS limitation by computing the timeInfo
components itself.
So it is usually (except for a little performane) no problem to return a reange too small here.

getCPUCycleCount

get a CPU specific cycle counter value.
Can be used for exact timing & performance measurements.
Notice, that the # of cycles has to be multiplied by the cycle time (1/cpu-frequency).

For x86:
the CPU cycle count register value is returned (RDTSC instruction).
answer 0 if RDTSC instruction is not supported (which is unlikely, nowadays).
For others:
answer 0

usage example(s):

     OperatingSystem getCPUCycleCount

getMicrosecondTime

getMillisecondTime

This returns the millisecond timers value.
The range is limited to 0..1fffffff (i.e. the SmallInteger range) to avoid
LargeInteger arithmetic when doing timeouts and delays.
Since this value is wrapping around in regular intervals, this can only be used for
short relative time deltas.
Use the millisecondTimeXXX:-methods to compare and add time deltas - these know about the wrap.

BAD DESIGN:
This should be changed to return some instance of RelativeTime,
and these computations moved there.

Do not use this method in application code since it is an internal (private)
interface. For compatibility with ST-80, use Time millisecondClockValue.

** This method raises an error - it must be redefined in concrete classes **

getMonotonicNanosecondTime

This returns the nanosecond timers value - if available.
On some machines, times with this precision may not be available,
on those, the returned value may be rounded towards some internal
clock resolution value.

If supported by the system, it uses a clock that cannot be set and represents
monotonic time since some unspecified starting point. This clock is not affected by
discontinuous jumps in the system time
(e.g., if the system administrator manually changes the clock), but is affected by
the incremental adjustments performed by adjtime(3) and NTP.

** This method raises an error - it must be redefined in concrete classes **

getOSTime

This returns the OS time.
The base of the returned value is not consistent across
different OS's - some return the number of millis since jan, 1st 1970;
others since 1900. The Time classes are prepared for this, and
converts as appropriate (by using my fromOSTime: conversion methods).

Do not use this method in application code since it is an internal (private)
interface. For compatibility with ST-80, use Time>>millisecondClockValue.
or use instances of Time, Date or Timestamp to work with.

** This method raises an error - it must be redefined in concrete classes **

getOSTimeWithMicros

This returns the OS time as a 2-element vector with milliseconds (as before)
plus microseconds.
The base of the returned value is not consistent across
different OS's - some return the number of microseconds since jan, 1st 1970;
others since 1900. The Time classes are prepared for this, and
converts as appropriate (by using my fromOSTime: conversion methods).

Don't use this method in application code since it is an internal (private)
interface. For compatibility with ST-80, use Time>>millisecondClockValue.
or use instances of Time, Date or Timestamp to work with.

getOSTimeWithNanos

This returns the OS time as a 2-element vector with milliseconds (as before)
plus nanoseconds.
The base of the returned value is not consistent across
different OS's - some return the number of microseconds since jan, 1st 1970;
others since 1900. The Time classes are prepared for this, and
converts as appropriate (by using my fromOSTime: conversion methods).

Don't use this method in application code since it is an internal (private)
interface.
For compatibility use instances of Time, Date or Timestamp to work with.

usage example(s):

     OperatingSystem getOSTime              1525868295396
     OperatingSystem getOSTimeWithMicros    -> #(1525868292534 220) 
     OperatingSystem getOSTimeWithNanos     -> #(1525868325652 456000)

getRealNanosecondTime

This returns the microsecond timers value - if available.
On some machines, times with this precision may not be available,
on those, the returned value may be rounded towards some internal
clock resolution value.
Note, that the timers value is not monotonic,
it may jump forward or backward if the sytsems time is changed by e.g. NTP
or the system administrator!

** This method raises an error - it must be redefined in concrete classes **

maximumMillisecondTimeDelta

this returns the maximum delta supported by millisecondCounter
based methods. The returned value is half the value at which the
timer wraps.

millisecondDelay: millis

delay execution for millis milliseconds or until the next event arrives.
All other threads proceed as usual.
Better use a Delay, however, a delay cannot be used in the event handler or scheduler.

usage example(s):

     OperatingSystem millisecondDelay:5000

millisecondTime: msTime1 isAfter: msTime2

return true if msTime1 is after msTime2, false if not.
The two arguments are supposed to be millisecond times
(such as returned getMillisecondTime) which wrap at 16r1FFFFFFF.

This should really be moved to some RelativeTime class.

millisecondTimeAdd: msTime1 and: msTime2

Add two millisecond times (such as returned getMillisecondTime).
The returned value is msTime1 + msTime2 where a wrap occurs
at:16r1FFFFFFF (32-bit systems) or:16r1FFFFFFFFFFFFFFF (64-bit systems).

This should really be moved to some RelativeTime class.

millisecondTimeDeltaBetween: msTime1 and: msTime2

subtract two millisecond times (such as returned getMillisecondTime)
and return the difference. Since milli-times wrap (at 16r01FFFFFFF),
some special handling is built-in here.
The returned value is msTime1 - msTime2. The returned value is invalid
if the delta is >= 0x10000000.

This should really be moved to some RelativeTime class;
better yet: create a subclass of Integer named LimitedRangeInteger.

usage example(s):

     OperatingSystem millisecondTimeAdd:16r0FFFFFFF and:1
     OperatingSystem millisecondTimeAdd:16r0FFFFFFF and:(16 / 3)
     OperatingSystem millisecondTimeAdd:16r0FFFFFFF and:1000

     OperatingSystem millisecondTimeDeltaBetween:0 and:16r0FFFFFFF
     OperatingSystem millisecondTimeDeltaBetween:0 and:16r1FFFFFFF
     OperatingSystem millisecondTimeDeltaBetween:16r1FFFFFFF and:0

     OperatingSystem millisecondTimeDeltaBetween:(13/3) and:16r0FFFFFFF
     OperatingSystem millisecondTimeDeltaBetween:999 and:16r0FFFFFFF

     OperatingSystem millisecondTime:0 isAfter:16r0FFFFFFF
     OperatingSystem millisecondTime:0 isAfter:16r1FFFFFFF
     OperatingSystem millisecondTime:(13/3) isAfter:16r0FFFFFFF
     OperatingSystem millisecondTime:999 isAfter:16r0FFFFFFF

     OperatingSystem millisecondTime:0 isAfter:0
     OperatingSystem millisecondTime:(13/3) isAfter:0
     OperatingSystem millisecondTime:999 isAfter:0

     OperatingSystem millisecondTime:1 isAfter:0
     OperatingSystem millisecondTime:(13/3) isAfter:2
     OperatingSystem millisecondTime:999 isAfter:900

     |t1 t2|

     t1 := Time millisecondClockValue.
     (Delay forMilliseconds:1) wait.
     t2 := Time millisecondClockValue.
     OperatingSystem millisecondTimeDeltaBetween:t2 and:t1

sleep: numberOfSeconds

cease ANY action for some time. This suspends the whole smalltalk
(unix-) process for some time.
Not really useful since not even low-prio processes and interrupt
handling will run during the sleep.
Use either OperatingSystem>>millisecondDelay: (which makes all
threads sleep, but handles interrupts) or use a Delay (which makes
only the calling thread sleep).

** This method raises an error - it must be redefined in concrete classes **

timeInfoClass

timeInfoFromSeconds: osSeconds localTime: isLocalTime

return a timeInfo structure containing values for the given OS-second value.
An internal helper

timeInfoFromSeconds: osSeconds milliseconds: osMilliSeconds localTime: isLocalTime

return a timeInfo structure containing values for the given OS-second value.
An internal helper

** This method raises an error - it must be redefined in concrete classes **

timeZoneInfoClass

utcOffset

OperatingSystem utcOffset

users & groups

getApplicationDataDirectoryFor: appName

return the directory, where user-and-application-specific private files are to be
located (ini-files, preferences etc.).
Under windows, something like 'C:\Users\Administrator\AppData\Roaming\<appName>'
is returned, here, the fallback ~/.<appName> is returned.
Notice that only the name is returned; the directory is not guaranteed to exist.

usage example(s):

     OperatingSystem getApplicationDataDirectoryFor:'expecco'

getDesktopDirectory

return the name of the user's desktop directory.
The fallback here returns the user's home directory.

usage example(s):

     OperatingSystem getDesktopDirectory

getDocumentsDirectory

return your documents directory.
Under windows, that's the real 'Documents' or 'My Documents'.
The fallback here returns the user's home directory.

usage example(s):

     OperatingSystem getDocumentsDirectory

getEffectiveGroupID

return the current users (that's you) effective numeric group id.
This is only different from getGroupID, if you have ST/X running
as a setuid program (of which you should think about twice).

usage example(s):

     OperatingSystem getEffectiveGroupID

getEffectiveUserID

return the current users (that's you) effective numeric user id.
This is only different from getUserID, if you have ST/X running
as a setuid program (of which you should think about twice).

usage example(s):

     OperatingSystem getEffectiveUserID

getFullUserName

return a string with the users full name (that's you) - if available.
If not, return the login name as a fallBack.

usage example(s):

     OperatingSystem getFullUserName

getFullUserNameFromID: userID

return a string with the users full name - if available.
If not, return the login name as a fallBack.

usage example(s):

     OperatingSystem getFullUserNameFromID:0
     OperatingSystem getFullUserNameFromID:(OperatingSystem getUserID)

     OperatingSystem getUserNameFromID:(OperatingSystem getUserID)

getGroupID

return the current users (that's you) numeric group id

usage example(s):

     OperatingSystem getGroupID

getGroupNameFromID: aNumber

return the group-name-string for a given numeric group-id

usage example(s):

     OperatingSystem getGroupNameFromID:0
     OperatingSystem getGroupNameFromID:10

getHomeDirectory

return the name of the users home directory
(i.e. yours)

** This method raises an error - it must be redefined in concrete classes **

getLoginName

return a string with the users login name (that's yours)

** This method raises an error - it must be redefined in concrete classes **

getUserID

return the current users (that's you) numeric user id

usage example(s):

     OperatingSystem getUserID

getUserNameFromID: aNumber

return the user-name-string for a given numeric user-id.
This is the login name, not the fullName.

usage example(s):

     OperatingSystem getUserNameFromID:0
     OperatingSystem getUserNameFromID:100
     OperatingSystem getUserNameFromID:9991
     OperatingSystem getUserNameFromID:(OperatingSystem getUserID)

isRunningWithElevatedRootOrAdminRights

actually: don't know

isRunningWithRootOrAdminRights

actually: don't know

userInfoOf: aNameOrID

return a dictionary filled with userinfo. The argument can be either
a string with the users name or its numeric id.
Notice, that not all systems provide (all of) this info;
DOS systems return nothing;
non-SYSV4 systems have no age/comment.
Portable applications may want to check the systemType and NOT depend
on all keys to be present in the returned dictionary.
Another notice: on some systems (SYSV4), the gecos field includes multiple
entries (i.e. not just the name), separated by commas. You may want to
extract any substring, up to the first comma to get the real life name.

usage example(s):

     OperatingSystem userInfoOf:'root'
     OperatingSystem userInfoOf:1
     OperatingSystem userInfoOf:'claus'
     OperatingSystem userInfoOf:'fooBar'
     OperatingSystem userInfoOf:(OperatingSystem getUserID)

waiting for events

blockingChildProcessWait: return true, if childProcessWait: blocks, if no children are ready.
On those systems, we must be somewhat careful when looking out for
a subprocesses status (to avoid blocking).
childProcessWait: blocking pid: pidToWait: get status changes from child processes.
Return an OSProcessStatus or nil, if no process has terminated.
If blocking is true, we wait until a process changed state,
otherwise we return immediately.
Note that win32 needs to know the HANDLE of the process on which
it waits. In case of an error, THIS ALWAYS WAITS and then times out.

** This method raises an error - it must be redefined in concrete classes **
isBlockingOn: fd: return the blocking attribute - if set (which is the default)
a read on the fileDescriptor will block until data is available.
If clear, a read operation will immediately return with a value nil.
Also affects write operations, which may perform partial writes when
blocking is off

** This method raises an error - it must be redefined in concrete classes **
numAvailableForReadOn: fd: return the number of bytes available for reading, without blocking.
readCheck: fd: return true, if a read is possible without blocking.
This is the case if data is available on a filedescriptor
or the read would return an error.
This depends on a working select or FIONREAD to be provided by the OS.
readWriteCheck: fd: return true, if filedescriptor can be read or written without blocking.
This is the case if data is available on a filedescriptor
or the read or write would return an error.
This is actually only used with sockets, to wait for a connect to
be finished.
selectOn: fd1 and: fd2 withTimeOut: millis: wait for any fd to become ready; timeout after t milliseconds.
A zero timeout-time will immediately return (i.e. poll).
Return fd if i/o ok, nil if timed-out or interrupted.
Obsolete:
This is a leftover method and will vanish.

** This is an obsolete interface - do not use it (it may vanish in future versions) **
selectOn: fd withTimeOut: millis: wait for aFileDesriptor to become ready; timeout after t milliseconds.
Return true, if i/o ok, false if timed-out or interrupted.
With 0 as timeout argument, this can be used to check for availability
of read-data.
Experimental.
selectOnAny: fdArray withTimeOut: millis: wait for any fd in fdArray (an Array of integers) to become ready;
timeout after t milliseconds. An empty set will always wait.
Return first ready fd if i/o ok, nil if timed-out or interrupted.
Experimental.
selectOnAnyReadable: fdArray withTimeOut: millis: wait for any fd in fdArray (an Array of integers) to become ready for
reading. Timeout after t milliseconds. An empty set will always wait.
A zero timeout-time will immediately return (i.e. poll).
Return first ready fd if i/o ok, nil if timed-out or interrupted.
Experimental.
selectOnAnyReadable: readFdArray writable: writeFdArray exception: exceptFdArray readableInto: readableResultFdArray writableInto: writableResultFdArray exceptionInto: exceptionResultFdArray withTimeOut: millis: wait for any fd in readFdArray (an Array of integers) to become ready for reading,
writeFdArray to become ready for writing,
or exceptFdArray to arrive exceptional data (i.e. out-of-band data).
Timeout after t milliseconds or - if the timeout time is 0 - immediately..
Empty fd-sets will always wait. Zero time can be used to poll file-
descriptors (i.e. to check if I/O possible without blocking).
The corresponding filedescriptors which are ready are returned in readableResultFdArray,
writableResultFdArray and exceptionResultFdArray respectively.

Return the (overall) number of selected filedescriptors.
readableResultFdArray, writableResultFdArray and exceptionResultFdArray will
get a nil-value stored into the slot after the last valid fileDescriptor;
Thus, the caller can simply scan these arrays upTo the end or a nil value.

** This method raises an error - it must be redefined in concrete classes **
selectOnAnyReadable: readFdArray writable: writeFdArray exception: exceptFdArray withTimeOut: millis: wait for any fd in readFdArray (an Array of integers) to become ready for
reading, writeFdArray to become ready for writing, or exceptFdArray to
arrive exceptional data (i.e. out-of-band data).
Timeout after t milliseconds or, if the timeout time is 0, immediately..
Empty fd-sets will always wait. Zero time can be used to poll file-
descriptors (i.e. to check if I/O possible without blocking).
Return first ready fd if I/O ok, nil if timed-out or interrupted.
setBlocking: aBoolean on: fd: set/clear the blocking attribute - if set (which is the default)
a read on the fileDescriptor will block until data is available.
If cleared, a read operation will immediately return with a value of nil.
Also affects write operations, which may perform partial writes when
blocking is off. Answer the previous blocking status.

** This method raises an error - it must be redefined in concrete classes **
writeCheck: fd: return true, if filedescriptor can be written without blocking.
This is the case if data can be written to a filedescriptor
or the write would return an error.
writeExceptionCheck: fd: return true, if filedescriptor can be written without blocking
or has an exception event pending.
This is the case if data can be written to a filedescriptor
or the write would return an error.
This is actually only used with sockets, to wait for a connect to
be finished.

Private classes:

    PrinterInfo
    TimeInfo
    TimeZoneInfo

Examples:

various queries

  Transcript
      showCR:'hello ' , (OperatingSystem getLoginName)

  OperatingSystem isUNIXlike ifTrue:[
      Transcript showCR:'this is some UNIX-like OS'
  ] ifFalse:[
      Transcript showCR:'this OS is not UNIX-like'
  ]

  Transcript
      showCR:'this machine is called ' , OperatingSystem getHostName

  Transcript
      showCR:('this machine is in the '
             , OperatingSystem getDomainName
             , ' domain')

  Transcript
      showCR:('this machine''s CPU is a '
             , OperatingSystem getCPUType
             )

  Transcript showCR:'executing ls command ...'.
  OperatingSystem executeCommand:'ls'.
  Transcript showCR:'... done.'.

locking a file (should be executed on two running smalltalks - not in two threads):

  |f|

  f := 'testFile' asFilename readWriteStream.

  10 timesRepeat:[
      'about to lock ...' printCR.
      [
        OperatingSystem
          lockFD:(f fileDescriptor)
          shared:false
          blocking:false
      ] whileFalse:[
          'process ' print. OperatingSystem getProcessId print. ' is waiting' printCR.
          Delay waitForSeconds:1
      ].
      'LOCKED ...' printCR.
      Delay waitForSeconds:10.
      'unlock ...' printCR.
      (OperatingSystem
          unlockFD:(f fileDescriptor)) printCR.
      Delay waitForSeconds:3.
  ]

ST/X 7.2.0.0; WebServer 1.670 at bd0aa1f87cdd.unknown:8081; Sat, 20 Apr 2024 04:25:44 GMT