"{ Package: 'stx:libbasic2' }"

Object subclass:#TerminalSession

	instanceVariableNames:'inStream outStream errStream readerProcess shellPid shellCommand

		shellDirectory readerDelay pluggableCheckBeforeReadAction

		pluggableProcessInputAction'

	classVariableNames:'Debug'

	poolDictionaries:''

	category:'Views-TerminalViews'

!

!TerminalSession class methodsFor:'documentation'!

documentation

"

    This keeps the state and API to interact with another program

    via a terminal session. Under Unix, a pseudo-tty connection

    is used; other operating systems might use other mechanisms.

    This is (currently) mostly used by the TerminalView application,

    but can be used whereever more control is needed than a simple pipe

    offers (such as terminal emulation, window size, CTRL-c support etc.)

    Extracted from TerminalView, which is refactored, once this is stable.

"

! !

!TerminalSession class methodsFor:'initialization'!

initialize

    Debug := false.

    "

     self initialize

    "

! !

!TerminalSession methodsFor:'accessing'!

errStream

    ^ errStream

!

inStream

    ^ inStream

!

outStream

    ^ outStream

!

pluggableCheckBeforeReadAction:something

    pluggableCheckBeforeReadAction := something.

!

pluggableProcessInputAction:something

    pluggableProcessInputAction := something.

!

shellCommand

    ^ shellCommand

!

shellDirectory

    ^ shellDirectory

!

shellPid

    ^ shellPid

! !

!TerminalSession methodsFor:'initialization & release'!

closeDownShell

    "shut down my shell process and stop the background reader thread."

    |pid|

    (pid := shellPid) notNil ifTrue:[

        Debug ifTrue:[

            Transcript print:'killing shell pid='; showCR:pid.

        ].

        OperatingSystem terminateProcessGroup:pid.

        OperatingSystem terminateProcess:pid.

        Delay waitForSeconds:1.

        shellPid notNil ifTrue:[

            OperatingSystem isMSWINDOWSlike ifFalse:[

                OperatingSystem killProcessGroup:pid.

            ].

            OperatingSystem killProcess:pid.

            shellPid := nil.

        ].

        OperatingSystem closePid:pid.

    ].

    "Modified: / 5.5.1999 / 18:43:02 / cg"

!

closeStreams

    inStream notNil ifTrue:[

        inStream isStream ifTrue:[inStream close].

        inStream := nil

    ].

    outStream notNil ifTrue:[

        outStream close.

        outStream := nil

    ].

    errStream notNil ifTrue:[

        errStream close.

        errStream := nil

    ].

!

killShell

    "shut down my shell process and stop the background reader thread."

    |pid|

    (pid := shellPid) notNil ifTrue:[

        Debug ifTrue:[

            Transcript show:'killing shell pid='; showCR:pid.

        ].

        OperatingSystem terminateProcessGroup:pid.

        OperatingSystem terminateProcess:pid.

        Delay waitForSeconds:1.

        shellPid notNil ifTrue:[

            OperatingSystem isMSWINDOWSlike ifFalse:[

                OperatingSystem killProcessGroup:pid.

            ].

            OperatingSystem killProcess:pid.

            shellPid := nil.

        ].

        OperatingSystem closePid:pid.

    ].

!

reinitialize

    shellPid := nil.

    inStream := outStream := errStream := nil.

!

startCommand:aCommand in:aDirectory environment:envIn setupTerminalWith:setupBlock terminatedAction:terminatedAction

    "start a command on a pseudo terminal. If the command arg is nil,

     a shell is started. If aDirectory is not nil, the command is

     executed in that directory.

     Also fork a reader process, to read the shell's output and

     tell me, whenever something arrives"

    |pty slaveFD execFdArray blocked exitStatus 

     stxToStdinPipe stdOutToStxPipe cmd shell args env shellAndArgs|

    shellCommand := aCommand.

    shellDirectory := aDirectory.

    OperatingSystem isMSWINDOWSlike ifTrue:[

        "use two pipes to COMMAND.COM"

        stxToStdinPipe := NonPositionableExternalStream makePipe.

        stxToStdinPipe isNil ifTrue:[

            self warn:(self class classResources string:'Could not create pipe to COMMAND.COM.'). 

            ^ self.

        ].

        stdOutToStxPipe := NonPositionableExternalStream makePipe.

        stdOutToStxPipe isNil ifTrue:[

            self warn:(self class classResources classResources string:'Could not create pipe from COMMAND.COM.'). 

            ^ self.

        ].

        "/ pipe readSide is p at:1;

        "/      writeSide is p at:2

        slaveFD := (stdOutToStxPipe at:2) fileDescriptor.

        execFdArray := Array 

                         with:(stxToStdinPipe at:1) fileDescriptor        "stdin"

                         with:slaveFD                                       "stdout"

                         with:slaveFD.                                      "stderr"

        outStream := stdOutToStxPipe at:1.

        inStream  := stxToStdinPipe at:2.

        shellAndArgs := OperatingSystem commandAndArgsForOSCommand:aCommand.

        shell := shellAndArgs at:1.

        args  := (shellAndArgs at:2) ? ''.

    ] ifFalse:[

        "Use a pseudo-tty"

        pty := NonPositionableExternalStream makePTYPair.

        pty isNil ifTrue:[

            self warn:'Cannot open pty.'.

            ^ self.

        ].

        "/ pty at:1 is the master;

        "/ pty at:2 is the slave

        inStream := outStream := (pty at:1).

        setupBlock value.

        "/ fork a shell process on the slave-side

        slaveFD := (pty at:2) fileDescriptor.

        execFdArray := Array with:slaveFD with:slaveFD with:slaveFD.

        aCommand isNil ifTrue:[

            shell := OperatingSystem getEnvironment:'SHELL'.

            shell size == 0 ifTrue:[

                shell := '/bin/sh'.

            ].

            cmd := shell asFilename baseName.

            args := (Array with:cmd).

        ] ifFalse:[

            shell := '/bin/sh'.

            args := (Array with:'sh' with:'-c' with:aCommand).

        ].

        env := Dictionary new.

        env declareAllFrom:envIn.

        env at:'SHELL' put:shell.

    ].

    blocked := OperatingSystem blockInterrupts.

    shellPid := Processor

               monitor:[

                  OperatingSystem

                      exec:shell

                      withArguments:args

                      environment:env

                      fileDescriptors:execFdArray

                      fork:true

                      newPgrp:true

                      inDirectory:aDirectory.

               ]

               action:[:status |

                    Debug ifTrue:[

                        Transcript show:'pid:'; showCR:status pid.

                        Transcript show:'status:'; showCR:status status.

                        Transcript show:'code:'; showCR:status code.

                        Transcript show:'core:'; showCR:status core.

                    ].

                    status stillAlive ifFalse:[

                        exitStatus := status.

                        OperatingSystem closePid:shellPid.

                        shellPid := nil.

                        terminatedAction value

                    ].

               ].

    blocked ifFalse:[

        OperatingSystem unblockInterrupts

    ].

    "close the slave side of the pty/pipes (only used by the child)"

    pty notNil ifTrue:[

        (pty at:2) close.

    ].

    stdOutToStxPipe notNil ifTrue:[

        (stdOutToStxPipe at:2) close.

        (stxToStdinPipe at:1) close.

    ].

    shellPid isNil ifTrue:[

        self warn:'Cannot start shell'.

        outStream close.

        inStream close.

        inStream := outStream := nil.

        ^ self.

    ].

    "Created: / 20.7.1998 / 18:19:32 / cg"

    "Modified: / 5.5.1999 / 17:28:37 / cg"

! !

!TerminalSession methodsFor:'input / output'!

paste:someText

    "paste - redefined to send the chars to the shell instead

     of pasting into the view"

    |s nLines|

    s := someText.

    s isString ifTrue:[

        s := s asStringCollection

    ] ifFalse:[

        (s isKindOf:StringCollection) ifFalse:[

            self warn:'selection (' , s class name , ') is not convertable to Text'.

            ^ self

        ]

    ].

    (nLines := s size) == 0 ifTrue:[^ self].

    (nLines == 1 and:[(s at:1) size == 0]) ifTrue:[^ self].

    s keysAndValuesDo:[:idx :line |

        line notNil ifTrue:[inStream nextPutAll:line].

        idx ~~ nLines ifTrue:[

            self sendLineEnd.

        ]

    ].

    "Modified: / 12.6.1998 / 22:12:47 / cg"

!

sendLine:aString

    inStream nextPutAll:aString.

    self sendLineEnd

!

sendLineEnd

    OperatingSystem isMSDOSlike ifTrue:[

        inStream nextPut:Character return.

        inStream nextPut:Character linefeed.

    ] ifFalse:[

        inStream nextPut:Character return.

    ].

! !

!TerminalSession methodsFor:'misc'!

defineWindowSizeLines:numberOfLines columns:numberOfColumns

    | delta prevNumCols prevNumLines|

    "/ any idea, how to do this under windows ?

    OperatingSystem isUNIXlike ifTrue:[

        "/

        "/ tell the pty;

        "/ tell the shell;

        "/

        (inStream notNil 

        and:[inStream isExternalStream

        and:[inStream isOpen]]) ifTrue:[

            Debug ifTrue:[

                Transcript showCR:'TerminalSession [info]: changed len to ', numberOfLines printString.

            ].

            (OperatingSystem 

                setWindowSizeOnFileDescriptor:inStream fileDescriptor

                width:numberOfColumns

                height:numberOfLines) ifFalse:[

                Debug ifTrue:[

                    Transcript showCR:'TerminalSession [warning]: cannot change windowSize'.

                ].

            ].

        ].

        shellPid notNil ifTrue:[

            OperatingSystem sendSignal:OperatingSystem sigWINCH to:shellPid

        ]

    ].

    "Created: / 11.6.1998 / 22:51:39 / cg"

    "Modified: / 5.5.1999 / 19:45:09 / cg"

!

sendInterruptSignal

    "send an INT-signal to the shell (UNIX only)"

    shellPid notNil ifTrue:[

        OperatingSystem sendSignal:(OperatingSystem sigINT) to:shellPid negated.

    ].

    "Modified: / 10.6.1998 / 17:49:49 / cg"

!

sendKillSignal

    "send a KILL-signal to the shell (UNIX only)"

    shellPid notNil ifTrue:[

        OperatingSystem sendSignal:(OperatingSystem sigKILL) to:shellPid negated.

    ]

! !

!TerminalSession methodsFor:'reader process'!

readAnyAvailableData

    "read data from the stream,

     and sends me #processInput:n: events if something arrived.

     Returns the amount of data read."

    |buffer n bufferSize|

    outStream isNil ifTrue:[^ 0].   "/ already closed

    bufferSize := 256.

    buffer := String new:bufferSize.

    ExternalStream readErrorSignal handle:[:ex |

        n := 0

    ] do:[

        n := outStream nextAvailableBytes:bufferSize into:buffer startingAt:1.

        n > 0 ifTrue:[

            pluggableProcessInputAction notNil ifTrue:[

                pluggableProcessInputAction value:buffer value:n.

            ]

        ].

    ].

    ^ n

!

readerProcessLoop

    "look for the session's output"

    StreamError handle:[:ex |

        Transcript show:'Terminal(PTY-reader) [error]: '; showCR:ex description.

    ] do:[

        [true] whileTrue:[

            AbortOperationRequest handle:[:ex |

            ] do:[

                |n sensor|

                readerDelay notNil ifTrue:[ Delay waitForSeconds:readerDelay].

                outStream readWait.

                (pluggableCheckBeforeReadAction isNil

                or:[pluggableCheckBeforeReadAction value]) ifTrue:[

                    n := self readAnyAvailableData.

                    n == 0 ifTrue:[

                        "/ Windows IPC has a bug - it always

                        "/ returns 0 (when the command is idle)

                        "/ and says it's at the end (sigh)

                        OperatingSystem isMSWINDOWSlike ifTrue:[

                            Delay waitForSeconds:0.1

                        ] ifFalse:[

                            outStream atEnd ifTrue:[

                                outStream close. outStream := nil.

                                inStream close.  inStream := nil.

                                Processor activeProcess terminate.

                            ] ifFalse:[

                                "/ this should not happen.

                                Delay waitForSeconds:0.1

                            ]

                        ].

                    ]

                ]

            ]

        ]

    ]

!

startReaderProcess

    "Start a reader process, which looks for the commands output,

     and sends me #processInput:n: events whenever something arrives."

    readerProcess isNil ifTrue:[

        readerProcess := [

            [

                self readerProcessLoop.

            ] ifCurtailed:[

                readerProcess := nil    

            ]

        ] fork. "/ forkAt:9.

        readerProcess name:'pty reader'.

    ]

    "

     VT100TerminalView openShell

    "

    "Modified: / 5.5.1999 / 17:58:02 / cg"

    "Modified: / 28.1.2002 / 21:10:13 / micha"

!

stopReaderProcess

    "stop the background reader thread"

        "/ give it a chance to really terminate

        Processor yield.

    ].

! !

!TerminalSession class methodsFor:'documentation'!

version

!

version_CVS

! !

TerminalSession initialize!