"

 COPYRIGHT (c) 1989 by Claus Gittinger

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

NonPositionableExternalStream subclass:#PipeStream

	instanceVariableNames:'commandString pid exitStatus exitSema exitAction'

	classVariableNames:'BrokenPipeSignal'

	poolDictionaries:''

	category:'Streams-External'

!

!PipeStream primitiveDefinitions!

%{

#if defined(NT) || defined(WIN32) || defined(MSDOS)

# undef UNIX_LIKE

# define MSDOS_LIKE

#endif

#if defined(__openVMS__)

# undef __new

#endif

#include <stdio.h>

#define _STDIO_H_INCLUDED_

#include <errno.h>

#define _ERRNO_H_INCLUDED_

#ifndef transputer

# include <sys/types.h>

# include <sys/stat.h>

#endif

/*

 * on some systems errno is a macro ... check for it here

 */

#ifndef errno

 extern errno;

#endif

#ifdef LINUX

# define BUGGY_STDIO_LIB

#endif

%}

! !

!PipeStream primitiveFunctions!

%{

/*

 * no longer needed - popen is useless ...

 */

#undef NEED_POPEN_WITH_VFORK

/*

 * some systems (i.e. ultrix) use fork;

 * were better off with a popen based on vfork ...

 */

#ifdef NEED_POPEN_WITH_VFORK

static int popen_pid = 0;

FILE *

popen(command, type)

/* const */ char *command;

/* const */ char *type;

{

    int pipes[2];

    int itype = (strcmp(type, "w") == 0 ? 1 : 0);

    if (pipe(pipes) == -1)

	return NULL;

    switch (popen_pid = vfork()) {

    case -1:

	(void)close(pipes[0]);

	(void)close(pipes[1]);

	return NULL;

    case 0:

	if (itype) {

	    dup2(pipes[0], fileno(stdin));

	    close(pipes[1]);

	} else {

	    dup2(pipes[1], fileno(stdout));

	    close(pipes[0]);

	}

	execl("/bin/sh", "/bin/sh", "-c", command, 0);

	fprintf(stderr, "XRN Error: failed the execlp\n");

	_exit(-1);

	/* NOTREACHED */

    default:

	    if (itype) {

		close(pipes[0]);

		return fdopen(pipes[1], "w");

	    } else {

		close(pipes[1]);

		return fdopen(pipes[0], "r");

	    }

    }

}

int

pclose(str)

FILE *str;

{

    int pd = 0;

    int status;

    int err;

    err = fclose(str);

    do {

	if ((pd = wait(&status)) == -1)

	{

		err = EOF;

		break;

	}

    } while (pd !=  popen_pid);

    if (err == EOF)

	return  -1;

    if (status)

	status >>= 8;   /* exit status in high byte */

    return status;

}

#endif /* NEED_POPEN_WITH_VFORK */

%}

! !

!PipeStream class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1989 by Claus Gittinger

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

!

documentation

"

    Pipestreams allow reading or writing from/to a unix command.

    For example, to get a stream reading the output of an 'ls -l'

    command, a PipeStream can be created with:

	PipeStream readingFrom:'ls -l'

    the characters of the commands output can be read using the

    standard stream messages as next, nextLine etc.

    If a writing pipeStream is written to, after the command has finished,

    UNIX will generate an error-signal (SIGPIPE), which will raise the BrokenPipeSignal. 

    Thus, to handle this condition correctly, the following code is suggested:

	|p|

	p := PipeStream writingTo:'echo hello'.

	PipeStream brokenPipeSignal handle:[:ex |

	    'broken pipe' printNewline.

	    p shutDown.

	    ex return

	] do:[

	    p nextPutLine:'oops'.

	   'after write' printNewline.

	    p close.

	   'after close' printNewline

	]

    Notice, that iff the Stream is buffered, the Signal may occur some time after

    the write - or even at close time; to avoid a recursive signal in the exception

    handler, a #shutDown is useful there; if you use close in the handler, this would

    try to send any buffered output to the pipe, leading to another brokenPipe exception.

    Buffered pipes do not work with Linux - the stdio library seems to be

    buggy (trying to restart the read ...)

    Currently, no filtering pipeStreams (i.e. both reading AND writing) are provided.

    However, if you look at how things are setup, this can be implemented using the

    low level primitives #mapePipe and #executeCommand from the OS class protocol.

    [author:]

	Claus Gittinger

    [see also:]

	ExternalStream FileStream Socket

	OperatingSystem

"

! !

!PipeStream class methodsFor:'initialization'!

initialize

    "setup the signal"

    BrokenPipeSignal isNil ifTrue:[

	BrokenPipeSignal := WriteErrorSignal newSignalMayProceed:true.

	BrokenPipeSignal nameClass:self message:#brokenPipeSignal.

	BrokenPipeSignal notifierString:'write on a pipe with no one to read'.

    ]

! !

!PipeStream class methodsFor:'instance creation'!

readingFrom:commandString

    "create and return a new pipeStream which can read from the unix command

     given by command."

    ^ (self basicNew) readingFrom:commandString

    "unix:

	PipeStream readingFrom:'ls -l'.

    "

    "

	p := PipeStream readingFrom:'ls -l'.

	Transcript showCR:p nextLine.

	p close

    "

    "

	|s|

	s := PipeStream readingFrom:'sh -c sleep\ 600'.

	(Delay forSeconds:2) wait.

	s shutDown

    "

    "vms:

	PipeStream readingFrom:'dir'.

    "

    "

	|p|

	p := PipeStream readingFrom:'dir'.

	Transcript showCR:p nextLine.

	p close

    "

    "msdos:

	PipeStream readingFrom:'dir'.

    "

    "

	|p|

	p := PipeStream readingFrom:'dir'.

	Transcript showCR:p nextLine.

	p close

    "

    "Modified: 24.4.1996 / 09:09:25 / stefan"

!

readingFrom:commandString errorDisposition:handleError inDirectory:aDirectory

    "similar to #readingFrom, but changes the directory while

     executing the command. Use this if a command is to be

     executed in another directory, to avoid any OS dependencies

     in your code.

     handleError may be one of #discard #inline #stderr (default), which causes

     stderr to me discarded (/dev/null), merged into the PipeStream or written

     to smalltalks stderr."

    |cmd tmpComFile pipe|

    (OperatingSystem platformName == #vms) ifTrue:[

	tmpComFile := OperatingSystem createCOMFileForVMSCommand:commandString in:aDirectory.

	cmd := '@' , tmpComFile osName.

	pipe := self readingFrom:cmd.

	pipe notNil ifTrue:[

	    pipe exitAction:[tmpComFile delete].

	] ifFalse:[

	    tmpComFile delete

	].

	^ pipe

    ].

    (OperatingSystem platformName == #win32) ifTrue:[

	^ (self basicNew) readingFrom:commandString inDirectory:aDirectory.

    ].

    "/ unix - prepend a 'cd' to the command

    cmd := 'cd ' , aDirectory asFilename name, '; ' , commandString.

    handleError == #discard ifTrue:[

	cmd := cmd, ' 2>/dev/null'.

    ] ifFalse:[

	handleError == #inline ifTrue:[

	    cmd := cmd, ' 2>&1'.

        ]

    ].

    ^ self readingFrom:cmd

    "Created: 24.9.1997 / 09:32:35 / stefan"

    "Modified: 20.1.1998 / 17:19:33 / md"

!

readingFrom:commandString inDirectory:aDirectory

    "similar to #readingFrom, but changes the directory while

     executing the command. Use this if a command is to be

     executed in another directory, to avoid any OS dependencies

     in your code."

     ^ self 

	readingFrom:commandString

	errorDisposition:#stderr 

	inDirectory:aDirectory

    "Modified: 24.9.1997 / 09:33:48 / stefan"

!

writingTo:commandString

    "create and return a new pipeStream which can write to the unix command

     given by command."

    ^ (self basicNew) writingTo:commandString

    "unix:

	 PipeStream writingTo:'sort'

    "

!

writingTo:commandString inDirectory:aDirectory

    "similar to #writingTo, but changes the directory while

     executing the command. Use this if a command is to be

     executed in another directory, to avoid any OS dependencies

     in your code."

    |cmd tmpComFile pipe|

    (OperatingSystem platformName == #vms) ifTrue:[

	tmpComFile := OperatingSystem createCOMFileForVMSCommand:commandString in:aDirectory.

	cmd := '@' , tmpComFile osName.

	pipe := self writingTo:cmd.

	pipe notNil ifTrue:[

	    pipe exitAction:[tmpComFile delete].

	] ifFalse:[

	    tmpComFile delete

	].

	^ pipe

    ].

    "/ unix - prepend a 'cd' to the command

    cmd := 'cd ' , aDirectory asFilename name, '; ' , commandString.

    ^ self writingTo:cmd

! !

!PipeStream class methodsFor:'Signal constants'!

brokenPipeSignal

    "return the signal used to handle SIGPIPE unix-signals.

     Since SIGPIPE is asynchronous, we can't decide which smalltalk process

     should handle BrokenPipeSignal. So the system doesn't raise 

     BrokenPipeSignal for SIGPIPE any longer."

    ^ BrokenPipeSignal

    "Modified: 24.9.1997 / 09:43:23 / stefan"

! !

!PipeStream methodsFor:'accessing'!

commandString

    "return the command string"

    ^ commandString

!

exitStatus

    "return exitStatus"

    ^ exitStatus

    "Created: 28.12.1995 / 14:54:41 / stefan"

!

pid

    "return pid"

    ^ pid

    "Created: 28.12.1995 / 14:54:30 / stefan"

! !

!PipeStream methodsFor:'instance release'!

closeFile

    "low level close

     This waits for the command to finish. 

     Use shutDown for a fast (nonBlocking) close."

    filePointer notNil ifTrue:[

	super closeFile.

	filePointer := nil.

	pid notNil ifTrue:[

	    [

		pid notNil ifTrue:[

		    exitSema wait.

		]

	    ] valueUninterruptably

	].

    ].

!

closeFileDescriptor

    "alternative very low level close 

     This closes the underlying OS-fileDescriptor 

     - and will NOT write any buffered data to the stream.

     You have been warned."

    |action|

%{  

#if !defined(transputer)

    OBJ fp;

    FILE *f;

    if ((fp = __INST(filePointer)) != nil) {

	__INST(filePointer) = nil;

	f = __FILEVal(fp);

#ifdef WIN32

	close(fileno(f));

#else

	__BEGIN_INTERRUPTABLE__

	close(fileno(f));

	__END_INTERRUPTABLE__

#endif

    }

#endif /* not transputer  */

%}.

    exitAction notNil ifTrue:[

	action := exitAction.

	exitAction := nil.

	action value.

    ]

!

disposed

    "redefined to avoid blocking in close."

    self shutDown

!

shutDown

    "close the Stream, ignoring any broken-pipe errors.

     Terminate the command"

    BrokenPipeSignal catch:[

	|tpid|

	Lobby unregister:self.

	self closeFileDescriptor.

	tpid := pid.                    "copy pid to avoid race"

	tpid notNil ifTrue:[

	    "/

	    "/ Terminate both the process and group, just in case the

	    "/ operating system does not support process groups.

	    "/

	    OperatingSystem terminateProcess:tpid.

	    OperatingSystem terminateProcessGroup:tpid.

	    pid := nil.

	].

    ]

    "Modified: 23.5.1996 / 09:15:41 / stefan"

! !

!PipeStream methodsFor:'private'!