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[/] [or1k/] [trunk/] [insight/] [tcl/] [unix/] [tclUnixPipe.c] - Blame information for rev 1774

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/*
 * tclUnixPipe.c --
 *
 *      This file implements the UNIX-specific exec pipeline functions,
 *      the "pipe" channel driver, and the "pid" Tcl command.
 *
 * Copyright (c) 1991-1994 The Regents of the University of California.
 * Copyright (c) 1994-1997 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclUnixPipe.c,v 1.1.1.1 2002-01-16 10:25:37 markom Exp $
 */
 
#include "tclInt.h"
#include "tclPort.h"
 
/*
 * The following macros convert between TclFile's and fd's.  The conversion
 * simple involves shifting fd's up by one to ensure that no valid fd is ever
 * the same as NULL.
 */
 
#define MakeFile(fd) ((TclFile)(((int)fd)+1))
#define GetFd(file) (((int)file)-1)
 
/*
 * This structure describes per-instance state of a pipe based channel.
 */
 
typedef struct PipeState {
    Tcl_Channel channel;/* Channel associated with this file. */
    TclFile inFile;     /* Output from pipe. */
    TclFile outFile;    /* Input to pipe. */
    TclFile errorFile;  /* Error output from pipe. */
    int numPids;        /* How many processes are attached to this pipe? */
    Tcl_Pid *pidPtr;    /* The process IDs themselves. Allocated by
                         * the creator of the pipe. */
    int isNonBlocking;  /* Nonzero when the pipe is in nonblocking mode.
                         * Used to decide whether to wait for the children
                         * at close time. */
} PipeState;
 
/*
 * Declarations for local procedures defined in this file:
 */
 
static int      PipeBlockModeProc _ANSI_ARGS_((ClientData instanceData,
                    int mode));
static int      PipeCloseProc _ANSI_ARGS_((ClientData instanceData,
                    Tcl_Interp *interp));
static int      PipeGetHandleProc _ANSI_ARGS_((ClientData instanceData,
                    int direction, ClientData *handlePtr));
static int      PipeInputProc _ANSI_ARGS_((ClientData instanceData,
                    char *buf, int toRead, int *errorCode));
static int      PipeOutputProc _ANSI_ARGS_((
                    ClientData instanceData, char *buf, int toWrite,
                    int *errorCode));
static void     PipeWatchProc _ANSI_ARGS_((ClientData instanceData, int mask));
static void     RestoreSignals _ANSI_ARGS_((void));
static int      SetupStdFile _ANSI_ARGS_((TclFile file, int type));
 
/*
 * This structure describes the channel type structure for command pipe
 * based IO:
 */
 
static Tcl_ChannelType pipeChannelType = {
    "pipe",                             /* Type name. */
    PipeBlockModeProc,                  /* Set blocking/nonblocking mode.*/
    PipeCloseProc,                      /* Close proc. */
    PipeInputProc,                      /* Input proc. */
    PipeOutputProc,                     /* Output proc. */
    NULL,                               /* Seek proc. */
    NULL,                               /* Set option proc. */
    NULL,                               /* Get option proc. */
    PipeWatchProc,                      /* Initialize notifier. */
    PipeGetHandleProc,                  /* Get OS handles out of channel. */
};
 
/*
 *----------------------------------------------------------------------
 *
 * TclpMakeFile --
 *
 *      Make a TclFile from a channel.
 *
 * Results:
 *      Returns a new TclFile or NULL on failure.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */
 
TclFile
TclpMakeFile(channel, direction)
    Tcl_Channel channel;        /* Channel to get file from. */
    int direction;              /* Either TCL_READABLE or TCL_WRITABLE. */
{
    ClientData data;
 
    if (Tcl_GetChannelHandle(channel, direction, (ClientData *) &data)
            == TCL_OK) {
        return MakeFile((int)data);
    } else {
        return (TclFile) NULL;
    }
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclpOpenFile --
 *
 *      Open a file for use in a pipeline.
 *
 * Results:
 *      Returns a new TclFile handle or NULL on failure.
 *
 * Side effects:
 *      May cause a file to be created on the file system.
 *
 *----------------------------------------------------------------------
 */
 
TclFile
TclpOpenFile(fname, mode)
    char *fname;                        /* The name of the file to open. */
    int mode;                           /* In what mode to open the file? */
{
    int fd;
 
    fd = open(fname, mode, 0666);
    if (fd != -1) {
        fcntl(fd, F_SETFD, FD_CLOEXEC);
 
        /*
         * If the file is being opened for writing, seek to the end
         * so we can append to any data already in the file.
         */
 
        if (mode & O_WRONLY) {
            lseek(fd, 0, SEEK_END);
        }
 
        /*
         * Increment the fd so it can't be 0, which would conflict with
         * the NULL return for errors.
         */
 
        return MakeFile(fd);
    }
    return NULL;
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclpCreateTempFile --
 *
 *      This function creates a temporary file initialized with an
 *      optional string, and returns a file handle with the file pointer
 *      at the beginning of the file.
 *
 * Results:
 *      A handle to a file.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */
 
TclFile
TclpCreateTempFile(contents, namePtr)
    char *contents;             /* String to write into temp file, or NULL. */
    Tcl_DString *namePtr;       /* If non-NULL, pointer to initialized
                                 * DString that is filled with the name of
                                 * the temp file that was created. */
{
    char fileName[L_tmpnam];
    TclFile file;
    size_t length = (contents == NULL) ? 0 : strlen(contents);
 
    tmpnam(fileName);
    file = TclpOpenFile(fileName, O_RDWR|O_CREAT|O_TRUNC);
    unlink(fileName);
 
    if ((file != NULL) && (length > 0)) {
        int fd = GetFd(file);
        while (1) {
            if (write(fd, contents, length) != -1) {
                break;
            } else if (errno != EINTR) {
                close(fd);
                return NULL;
            }
        }
        lseek(fd, 0, SEEK_SET);
    }
    if (namePtr != NULL) {
        Tcl_DStringAppend(namePtr, fileName, -1);
    }
    return file;
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclpCreatePipe --
 *
 *      Creates a pipe - simply calls the pipe() function.
 *
 * Results:
 *      Returns 1 on success, 0 on failure.
 *
 * Side effects:
 *      Creates a pipe.
 *
 *----------------------------------------------------------------------
 */
 
int
TclpCreatePipe(readPipe, writePipe)
    TclFile *readPipe;          /* Location to store file handle for
                                 * read side of pipe. */
    TclFile *writePipe;         /* Location to store file handle for
                                 * write side of pipe. */
{
    int pipeIds[2];
 
    if (pipe(pipeIds) != 0) {
        return 0;
    }
 
    fcntl(pipeIds[0], F_SETFD, FD_CLOEXEC);
    fcntl(pipeIds[1], F_SETFD, FD_CLOEXEC);
 
    *readPipe = MakeFile(pipeIds[0]);
    *writePipe = MakeFile(pipeIds[1]);
    return 1;
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclpCloseFile --
 *
 *      Implements a mechanism to close a UNIX file.
 *
 * Results:
 *      Returns 0 on success, or -1 on error, setting errno.
 *
 * Side effects:
 *      The file is closed.
 *
 *----------------------------------------------------------------------
 */
 
int
TclpCloseFile(file)
    TclFile file;       /* The file to close. */
{
    int fd = GetFd(file);
 
    /*
     * Refuse to close the fds for stdin, stdout and stderr.
     */
 
    if ((fd == 0) || (fd == 1) || (fd == 2)) {
        return 0;
    }
 
    Tcl_DeleteFileHandler(fd);
    return close(fd);
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclpCreateProcess --
 *
 *      Create a child process that has the specified files as its
 *      standard input, output, and error.  The child process runs
 *      asynchronously and runs with the same environment variables
 *      as the creating process.
 *
 *      The path is searched to find the specified executable.
 *
 * Results:
 *      The return value is TCL_ERROR and an error message is left in
 *      interp->result if there was a problem creating the child
 *      process.  Otherwise, the return value is TCL_OK and *pidPtr is
 *      filled with the process id of the child process.
 *
 * Side effects:
 *      A process is created.
 *
 *----------------------------------------------------------------------
 */
 
    /* ARGSUSED */
int
TclpCreateProcess(interp, argc, argv, inputFile, outputFile, errorFile,
        pidPtr)
    Tcl_Interp *interp;         /* Interpreter in which to leave errors that
                                 * occurred when creating the child process.
                                 * Error messages from the child process
                                 * itself are sent to errorFile. */
    int argc;                   /* Number of arguments in following array. */
    char **argv;                /* Array of argument strings.  argv[0]
                                 * contains the name of the executable
                                 * converted to native format (using the
                                 * Tcl_TranslateFileName call).  Additional
                                 * arguments have not been converted. */
    TclFile inputFile;          /* If non-NULL, gives the file to use as
                                 * input for the child process.  If inputFile
                                 * file is not readable or is NULL, the child
                                 * will receive no standard input. */
    TclFile outputFile;         /* If non-NULL, gives the file that
                                 * receives output from the child process.  If
                                 * outputFile file is not writeable or is
                                 * NULL, output from the child will be
                                 * discarded. */
    TclFile errorFile;          /* If non-NULL, gives the file that
                                 * receives errors from the child process.  If
                                 * errorFile file is not writeable or is NULL,
                                 * errors from the child will be discarded.
                                 * errorFile may be the same as outputFile. */
    Tcl_Pid *pidPtr;            /* If this procedure is successful, pidPtr
                                 * is filled with the process id of the child
                                 * process. */
{
    TclFile errPipeIn, errPipeOut;
    int joinThisError, count, status, fd;
    char errSpace[200];
    int pid;
 
    errPipeIn = NULL;
    errPipeOut = NULL;
    pid = -1;
 
    /*
     * Create a pipe that the child can use to return error
     * information if anything goes wrong.
     */
 
    if (TclpCreatePipe(&errPipeIn, &errPipeOut) == 0) {
        Tcl_AppendResult(interp, "couldn't create pipe: ",
                Tcl_PosixError(interp), (char *) NULL);
        goto error;
    }
 
    joinThisError = (errorFile == outputFile);
    pid = vfork();
    if (pid == 0) {
        fd = GetFd(errPipeOut);
 
        /*
         * Set up stdio file handles for the child process.
         */
 
        if (!SetupStdFile(inputFile, TCL_STDIN)
                || !SetupStdFile(outputFile, TCL_STDOUT)
                || (!joinThisError && !SetupStdFile(errorFile, TCL_STDERR))
                || (joinThisError &&
                        ((dup2(1,2) == -1) ||
                         (fcntl(2, F_SETFD, 0) != 0)))) {
            sprintf(errSpace,
                    "%dforked process couldn't set up input/output: ",
                    errno);
            write(fd, errSpace, (size_t) strlen(errSpace));
            _exit(1);
        }
 
        /*
         * Close the input side of the error pipe.
         */
 
        RestoreSignals();
        execvp(argv[0], &argv[0]);
        sprintf(errSpace, "%dcouldn't execute \"%.150s\": ", errno,
                argv[0]);
        write(fd, errSpace, (size_t) strlen(errSpace));
        _exit(1);
    }
    if (pid == -1) {
        Tcl_AppendResult(interp, "couldn't fork child process: ",
                Tcl_PosixError(interp), (char *) NULL);
        goto error;
    }
 
    /*
     * Read back from the error pipe to see if the child started
     * up OK.  The info in the pipe (if any) consists of a decimal
     * errno value followed by an error message.
     */
 
    TclpCloseFile(errPipeOut);
    errPipeOut = NULL;
 
    fd = GetFd(errPipeIn);
    count = read(fd, errSpace, (size_t) (sizeof(errSpace) - 1));
    if (count > 0) {
        char *end;
        errSpace[count] = 0;
        errno = strtol(errSpace, &end, 10);
        Tcl_AppendResult(interp, end, Tcl_PosixError(interp),
                (char *) NULL);
        goto error;
    }
 
    TclpCloseFile(errPipeIn);
    *pidPtr = (Tcl_Pid) pid;
    return TCL_OK;
 
    error:
    if (pid != -1) {
        /*
         * Reap the child process now if an error occurred during its
         * startup.
         */
 
        Tcl_WaitPid((Tcl_Pid) pid, &status, WNOHANG);
    }
 
    if (errPipeIn) {
        TclpCloseFile(errPipeIn);
    }
    if (errPipeOut) {
        TclpCloseFile(errPipeOut);
    }
    return TCL_ERROR;
}
 
/*
 *----------------------------------------------------------------------
 *
 * RestoreSignals --
 *
 *      This procedure is invoked in a forked child process just before
 *      exec-ing a new program to restore all signals to their default
 *      settings.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Signal settings get changed.
 *
 *----------------------------------------------------------------------
 */
 
static void
RestoreSignals()
{
#ifdef SIGABRT
    signal(SIGABRT, SIG_DFL);
#endif
#ifdef SIGALRM
    signal(SIGALRM, SIG_DFL);
#endif
#ifdef SIGFPE
    signal(SIGFPE, SIG_DFL);
#endif
#ifdef SIGHUP
    signal(SIGHUP, SIG_DFL);
#endif
#ifdef SIGILL
    signal(SIGILL, SIG_DFL);
#endif
#ifdef SIGINT
    signal(SIGINT, SIG_DFL);
#endif
#ifdef SIGPIPE
    signal(SIGPIPE, SIG_DFL);
#endif
#ifdef SIGQUIT
    signal(SIGQUIT, SIG_DFL);
#endif
#ifdef SIGSEGV
    signal(SIGSEGV, SIG_DFL);
#endif
#ifdef SIGTERM
    signal(SIGTERM, SIG_DFL);
#endif
#ifdef SIGUSR1
    signal(SIGUSR1, SIG_DFL);
#endif
#ifdef SIGUSR2
    signal(SIGUSR2, SIG_DFL);
#endif
#ifdef SIGCHLD
    signal(SIGCHLD, SIG_DFL);
#endif
#ifdef SIGCONT
    signal(SIGCONT, SIG_DFL);
#endif
#ifdef SIGTSTP
    signal(SIGTSTP, SIG_DFL);
#endif
#ifdef SIGTTIN
    signal(SIGTTIN, SIG_DFL);
#endif
#ifdef SIGTTOU
    signal(SIGTTOU, SIG_DFL);
#endif
}
 
/*
 *----------------------------------------------------------------------
 *
 * SetupStdFile --
 *
 *      Set up stdio file handles for the child process, using the
 *      current standard channels if no other files are specified.
 *      If no standard channel is defined, or if no file is associated
 *      with the channel, then the corresponding standard fd is closed.
 *
 * Results:
 *      Returns 1 on success, or 0 on failure.
 *
 * Side effects:
 *      Replaces stdio fds.
 *
 *----------------------------------------------------------------------
 */
 
static int
SetupStdFile(file, type)
    TclFile file;               /* File to dup, or NULL. */
    int type;                   /* One of TCL_STDIN, TCL_STDOUT, TCL_STDERR */
{
    Tcl_Channel channel;
    int fd;
    int targetFd = 0;            /* Initializations here needed only to */
    int direction = 0;           /* prevent warnings about using uninitialized
                                 * variables. */
 
    switch (type) {
        case TCL_STDIN:
            targetFd = 0;
            direction = TCL_READABLE;
            break;
        case TCL_STDOUT:
            targetFd = 1;
            direction = TCL_WRITABLE;
            break;
        case TCL_STDERR:
            targetFd = 2;
            direction = TCL_WRITABLE;
            break;
    }
 
    if (!file) {
        channel = Tcl_GetStdChannel(type);
        if (channel) {
            file = TclpMakeFile(channel, direction);
        }
    }
    if (file) {
        fd = GetFd(file);
        if (fd != targetFd) {
            if (dup2(fd, targetFd) == -1) {
                return 0;
            }
 
            /*
             * Must clear the close-on-exec flag for the target FD, since
             * some systems (e.g. Ultrix) do not clear the CLOEXEC flag on
             * the target FD.
             */
 
            fcntl(targetFd, F_SETFD, 0);
        } else {
            int result;
 
            /*
             * Since we aren't dup'ing the file, we need to explicitly clear
             * the close-on-exec flag.
             */
 
            result = fcntl(fd, F_SETFD, 0);
        }
    } else {
        close(targetFd);
    }
    return 1;
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclpCreateCommandChannel --
 *
 *      This function is called by the generic IO level to perform
 *      the platform specific channel initialization for a command
 *      channel.
 *
 * Results:
 *      Returns a new channel or NULL on failure.
 *
 * Side effects:
 *      Allocates a new channel.
 *
 *----------------------------------------------------------------------
 */
 
Tcl_Channel
TclpCreateCommandChannel(readFile, writeFile, errorFile, numPids, pidPtr)
    TclFile readFile;           /* If non-null, gives the file for reading. */
    TclFile writeFile;          /* If non-null, gives the file for writing. */
    TclFile errorFile;          /* If non-null, gives the file where errors
                                 * can be read. */
    int numPids;                /* The number of pids in the pid array. */
    Tcl_Pid *pidPtr;            /* An array of process identifiers.
                                 * Allocated by the caller, freed when
                                 * the channel is closed or the processes
                                 * are detached (in a background exec). */
{
    char channelName[20];
    int channelId;
    PipeState *statePtr = (PipeState *) ckalloc((unsigned) sizeof(PipeState));
    int mode;
 
    statePtr->inFile = readFile;
    statePtr->outFile = writeFile;
    statePtr->errorFile = errorFile;
    statePtr->numPids = numPids;
    statePtr->pidPtr = pidPtr;
    statePtr->isNonBlocking = 0;
 
    mode = 0;
    if (readFile) {
        mode |= TCL_READABLE;
    }
    if (writeFile) {
        mode |= TCL_WRITABLE;
    }
 
    /*
     * Use one of the fds associated with the channel as the
     * channel id.
     */
 
    if (readFile) {
        channelId = GetFd(readFile);
    } else if (writeFile) {
        channelId = GetFd(writeFile);
    } else if (errorFile) {
        channelId = GetFd(errorFile);
    } else {
        channelId = 0;
    }
 
    /*
     * For backward compatibility with previous versions of Tcl, we
     * use "file%d" as the base name for pipes even though it would
     * be more natural to use "pipe%d".
     */
 
    sprintf(channelName, "file%d", channelId);
    statePtr->channel = Tcl_CreateChannel(&pipeChannelType, channelName,
            (ClientData) statePtr, mode);
    return statePtr->channel;
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclGetAndDetachPids --
 *
 *      This procedure is invoked in the generic implementation of a
 *      background "exec" (An exec when invoked with a terminating "&")
 *      to store a list of the PIDs for processes in a command pipeline
 *      in interp->result and to detach the processes.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Modifies interp->result. Detaches processes.
 *
 *----------------------------------------------------------------------
 */
 
void
TclGetAndDetachPids(interp, chan)
    Tcl_Interp *interp;
    Tcl_Channel chan;
{
    PipeState *pipePtr;
    Tcl_ChannelType *chanTypePtr;
    int i;
    char buf[20];
 
    /*
     * Punt if the channel is not a command channel.
     */
 
    chanTypePtr = Tcl_GetChannelType(chan);
    if (chanTypePtr != &pipeChannelType) {
        return;
    }
 
    pipePtr = (PipeState *) Tcl_GetChannelInstanceData(chan);
    for (i = 0; i < pipePtr->numPids; i++) {
        sprintf(buf, "%ld", TclpGetPid(pipePtr->pidPtr[i]));
        Tcl_AppendElement(interp, buf);
        Tcl_DetachPids(1, &(pipePtr->pidPtr[i]));
    }
    if (pipePtr->numPids > 0) {
        ckfree((char *) pipePtr->pidPtr);
        pipePtr->numPids = 0;
    }
}
 
/*
 *----------------------------------------------------------------------
 *
 * PipeBlockModeProc --
 *
 *      Helper procedure to set blocking and nonblocking modes on a
 *      pipe based channel. Invoked by generic IO level code.
 *
 * Results:
 *      0 if successful, errno when failed.
 *
 * Side effects:
 *      Sets the device into blocking or non-blocking mode.
 *
 *----------------------------------------------------------------------
 */
 
        /* ARGSUSED */
static int
PipeBlockModeProc(instanceData, mode)
    ClientData instanceData;            /* Pipe state. */
    int mode;                           /* The mode to set. Can be one of
                                         * TCL_MODE_BLOCKING or
                                         * TCL_MODE_NONBLOCKING. */
{
    PipeState *psPtr = (PipeState *) instanceData;
    int curStatus;
    int fd;
 
#ifndef USE_FIONBIO    
    if (psPtr->inFile) {
        fd = GetFd(psPtr->inFile);
        curStatus = fcntl(fd, F_GETFL);
        if (mode == TCL_MODE_BLOCKING) {
            curStatus &= (~(O_NONBLOCK));
        } else {
            curStatus |= O_NONBLOCK;
        }
        if (fcntl(fd, F_SETFL, curStatus) < 0) {
            return errno;
        }
        curStatus = fcntl(fd, F_GETFL);
    }
    if (psPtr->outFile) {
        fd = GetFd(psPtr->outFile);
        curStatus = fcntl(fd, F_GETFL);
        if (mode == TCL_MODE_BLOCKING) {
            curStatus &= (~(O_NONBLOCK));
        } else {
            curStatus |= O_NONBLOCK;
        }
        if (fcntl(fd, F_SETFL, curStatus) < 0) {
            return errno;
        }
    }
#endif  /* !FIONBIO */
 
#ifdef  USE_FIONBIO
    if (psPtr->inFile) {
        fd = GetFd(psPtr->inFile);
        if (mode == TCL_MODE_BLOCKING) {
            curStatus = 0;
        } else {
            curStatus = 1;
        }
        if (ioctl(fd, (int) FIONBIO, &curStatus) < 0) {
            return errno;
        }
    }
    if (psPtr->outFile != NULL) {
        fd = GetFd(psPtr->outFile);
        if (mode == TCL_MODE_BLOCKING) {
            curStatus = 0;
        } else {
            curStatus = 1;
        }
        if (ioctl(fd, (int) FIONBIO,  &curStatus) < 0) {
            return errno;
        }
    }
#endif  /* USE_FIONBIO */
 
    return 0;
}
 
/*
 *----------------------------------------------------------------------
 *
 * PipeCloseProc --
 *
 *      This procedure is invoked by the generic IO level to perform
 *      channel-type-specific cleanup when a command pipeline channel
 *      is closed.
 *
 * Results:
 *      0 on success, errno otherwise.
 *
 * Side effects:
 *      Closes the command pipeline channel.
 *
 *----------------------------------------------------------------------
 */
 
        /* ARGSUSED */
static int
PipeCloseProc(instanceData, interp)
    ClientData instanceData;    /* The pipe to close. */
    Tcl_Interp *interp;         /* For error reporting. */
{
    PipeState *pipePtr;
    Tcl_Channel errChan;
    int errorCode, result;
 
    errorCode = 0;
    result = 0;
    pipePtr = (PipeState *) instanceData;
    if (pipePtr->inFile) {
        if (TclpCloseFile(pipePtr->inFile) < 0) {
            errorCode = errno;
        }
    }
    if (pipePtr->outFile) {
        if ((TclpCloseFile(pipePtr->outFile) < 0) && (errorCode == 0)) {
            errorCode = errno;
        }
    }
 
    if (pipePtr->isNonBlocking || TclInExit()) {
 
        /*
         * If the channel is non-blocking or Tcl is being cleaned up, just
         * detach the children PIDs, reap them (important if we are in a
         * dynamic load module), and discard the errorFile.
         */
 
        Tcl_DetachPids(pipePtr->numPids, pipePtr->pidPtr);
        Tcl_ReapDetachedProcs();
 
        if (pipePtr->errorFile) {
            TclpCloseFile(pipePtr->errorFile);
        }
    } else {
 
        /*
         * Wrap the error file into a channel and give it to the cleanup
         * routine.
         */
 
        if (pipePtr->errorFile) {
            errChan = Tcl_MakeFileChannel(
                (ClientData) GetFd(pipePtr->errorFile), TCL_READABLE);
        } else {
            errChan = NULL;
        }
        result = TclCleanupChildren(interp, pipePtr->numPids, pipePtr->pidPtr,
                errChan);
    }
 
    if (pipePtr->numPids != 0) {
        ckfree((char *) pipePtr->pidPtr);
    }
    ckfree((char *) pipePtr);
    if (errorCode == 0) {
        return result;
    }
    return errorCode;
}
 
/*
 *----------------------------------------------------------------------
 *
 * PipeInputProc --
 *
 *      This procedure is invoked from the generic IO level to read
 *      input from a command pipeline based channel.
 *
 * Results:
 *      The number of bytes read is returned or -1 on error. An output
 *      argument contains a POSIX error code if an error occurs, or zero.
 *
 * Side effects:
 *      Reads input from the input device of the channel.
 *
 *----------------------------------------------------------------------
 */
 
static int
PipeInputProc(instanceData, buf, toRead, errorCodePtr)
    ClientData instanceData;            /* Pipe state. */
    char *buf;                          /* Where to store data read. */
    int toRead;                         /* How much space is available
                                         * in the buffer? */
    int *errorCodePtr;                  /* Where to store error code. */
{
    PipeState *psPtr = (PipeState *) instanceData;
    int bytesRead;                      /* How many bytes were actually
                                         * read from the input device? */
 
    *errorCodePtr = 0;
 
    /*
     * Assume there is always enough input available. This will block
     * appropriately, and read will unblock as soon as a short read is
     * possible, if the channel is in blocking mode. If the channel is
     * nonblocking, the read will never block.
     */
 
    bytesRead = read(GetFd(psPtr->inFile), buf, (size_t) toRead);
    if (bytesRead > -1) {
        return bytesRead;
    }
    *errorCodePtr = errno;
    return -1;
}
 
/*
 *----------------------------------------------------------------------
 *
 * PipeOutputProc--
 *
 *      This procedure is invoked from the generic IO level to write
 *      output to a command pipeline based channel.
 *
 * Results:
 *      The number of bytes written is returned or -1 on error. An
 *      output argument contains a POSIX error code if an error occurred,
 *      or zero.
 *
 * Side effects:
 *      Writes output on the output device of the channel.
 *
 *----------------------------------------------------------------------
 */
 
static int
PipeOutputProc(instanceData, buf, toWrite, errorCodePtr)
    ClientData instanceData;            /* Pipe state. */
    char *buf;                          /* The data buffer. */
    int toWrite;                        /* How many bytes to write? */
    int *errorCodePtr;                  /* Where to store error code. */
{
    PipeState *psPtr = (PipeState *) instanceData;
    int written;
 
    *errorCodePtr = 0;
    written = write(GetFd(psPtr->outFile), buf, (size_t) toWrite);
    if (written > -1) {
        return written;
    }
    *errorCodePtr = errno;
    return -1;
}
 
/*
 *----------------------------------------------------------------------
 *
 * PipeWatchProc --
 *
 *      Initialize the notifier to watch the fds from this channel.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Sets up the notifier so that a future event on the channel will
 *      be seen by Tcl.
 *
 *----------------------------------------------------------------------
 */
 
static void
PipeWatchProc(instanceData, mask)
    ClientData instanceData;            /* The pipe state. */
    int mask;                           /* Events of interest; an OR-ed
                                         * combination of TCL_READABLE,
                                         * TCL_WRITABEL and TCL_EXCEPTION. */
{
    PipeState *psPtr = (PipeState *) instanceData;
    int newmask;
 
    if (psPtr->inFile) {
        newmask = mask & (TCL_READABLE | TCL_EXCEPTION);
        if (newmask) {
            Tcl_CreateFileHandler(GetFd(psPtr->inFile), mask,
                    (Tcl_FileProc *) Tcl_NotifyChannel,
                    (ClientData) psPtr->channel);
        } else {
            Tcl_DeleteFileHandler(GetFd(psPtr->inFile));
        }
    }
    if (psPtr->outFile) {
        newmask = mask & (TCL_WRITABLE | TCL_EXCEPTION);
        if (newmask) {
            Tcl_CreateFileHandler(GetFd(psPtr->outFile), mask,
                    (Tcl_FileProc *) Tcl_NotifyChannel,
                    (ClientData) psPtr->channel);
        } else {
            Tcl_DeleteFileHandler(GetFd(psPtr->outFile));
        }
    }
}
 
/*
 *----------------------------------------------------------------------
 *
 * PipeGetHandleProc --
 *
 *      Called from Tcl_GetChannelHandle to retrieve OS handles from
 *      inside a command pipeline based channel.
 *
 * Results:
 *      Returns TCL_OK with the fd in handlePtr, or TCL_ERROR if
 *      there is no handle for the specified direction.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */
 
static int
PipeGetHandleProc(instanceData, direction, handlePtr)
    ClientData instanceData;    /* The pipe state. */
    int direction;              /* TCL_READABLE or TCL_WRITABLE */
    ClientData *handlePtr;      /* Where to store the handle.  */
{
    PipeState *psPtr = (PipeState *) instanceData;
 
    if (direction == TCL_READABLE && psPtr->inFile) {
        *handlePtr = (ClientData) GetFd(psPtr->inFile);
        return TCL_OK;
    }
    if (direction == TCL_WRITABLE && psPtr->outFile) {
        *handlePtr = (ClientData) GetFd(psPtr->outFile);
        return TCL_OK;
    }
    return TCL_ERROR;
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_WaitPid --
 *
 *      Implements the waitpid system call on Unix systems.
 *
 * Results:
 *      Result of calling waitpid.
 *
 * Side effects:
 *      Waits for a process to terminate.
 *
 *----------------------------------------------------------------------
 */
 
Tcl_Pid
Tcl_WaitPid(pid, statPtr, options)
    Tcl_Pid pid;
    int *statPtr;
    int options;
{
    int result;
    pid_t real_pid;
 
    real_pid = (pid_t) pid;
    while (1) {
        result = (int) waitpid(real_pid, statPtr, options);
        if ((result != -1) || (errno != EINTR)) {
            return (Tcl_Pid) result;
        }
    }
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_PidObjCmd --
 *
 *      This procedure is invoked to process the "pid" Tcl command.
 *      See the user documentation for details on what it does.
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      See the user documentation.
 *
 *----------------------------------------------------------------------
 */
 
        /* ARGSUSED */
int
Tcl_PidObjCmd(dummy, interp, objc, objv)
    ClientData dummy;           /* Not used. */
    Tcl_Interp *interp;         /* Current interpreter. */
    int objc;                   /* Number of arguments. */
    Tcl_Obj *CONST *objv;       /* Argument strings. */
{
    Tcl_Channel chan;
    Tcl_ChannelType *chanTypePtr;
    PipeState *pipePtr;
    int i;
    Tcl_Obj *resultPtr, *longObjPtr;
 
    if (objc > 2) {
        Tcl_WrongNumArgs(interp, 1, objv, "?channelId?");
        return TCL_ERROR;
    }
    if (objc == 1) {
        Tcl_SetLongObj(Tcl_GetObjResult(interp), (long) getpid());
    } else {
        chan = Tcl_GetChannel(interp, Tcl_GetStringFromObj(objv[1], NULL),
                NULL);
        if (chan == (Tcl_Channel) NULL) {
            return TCL_ERROR;
        }
        chanTypePtr = Tcl_GetChannelType(chan);
        if (chanTypePtr != &pipeChannelType) {
            return TCL_OK;
        }
        pipePtr = (PipeState *) Tcl_GetChannelInstanceData(chan);
        resultPtr = Tcl_GetObjResult(interp);
        for (i = 0; i < pipePtr->numPids; i++) {
            longObjPtr = Tcl_NewLongObj((long) TclpGetPid(pipePtr->pidPtr[i]));
            Tcl_ListObjAppendElement(NULL, resultPtr, longObjPtr);
        }
    }
    return TCL_OK;
}
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[/] [or1k/] [trunk/] [insight/] [tcl/] [unix/] [tclUnixPipe.c] - Blame information for rev 1774

Line No.	Rev	Author	Line
1	578	markom	`/*`
2			`* tclUnixPipe.c --`
3			`*`
4			`* This file implements the UNIX-specific exec pipeline functions,`
5			`* the "pipe" channel driver, and the "pid" Tcl command.`
6			`*`
7			`* Copyright (c) 1991-1994 The Regents of the University of California.`
8			`* Copyright (c) 1994-1997 Sun Microsystems, Inc.`
9			`*`
10			`* See the file "license.terms" for information on usage and redistribution`
11			`* of this file, and for a DISCLAIMER OF ALL WARRANTIES.`
12			`*`
13			`* RCS: @(#) $Id: tclUnixPipe.c,v 1.1.1.1 2002-01-16 10:25:37 markom Exp $`
14			`*/`
15
16			`#include "tclInt.h"`
17			`#include "tclPort.h"`
18
19			`/*`
20			`* The following macros convert between TclFile's and fd's. The conversion`
21			`* simple involves shifting fd's up by one to ensure that no valid fd is ever`
22			`* the same as NULL.`
23			`*/`
24
25			`#define MakeFile(fd) ((TclFile)(((int)fd)+1))`
26			`#define GetFd(file) (((int)file)-1)`
27
28			`/*`
29			`* This structure describes per-instance state of a pipe based channel.`
30			`*/`
31
32			`typedef struct PipeState {`
33			`Tcl_Channel channel;/* Channel associated with this file. */`
34			`TclFile inFile; /* Output from pipe. */`
35			`TclFile outFile; /* Input to pipe. */`
36			`TclFile errorFile; /* Error output from pipe. */`
37			`int numPids; /* How many processes are attached to this pipe? */`
38			`Tcl_Pid pidPtr; / The process IDs themselves. Allocated by`
39			`* the creator of the pipe. */`
40			`int isNonBlocking; /* Nonzero when the pipe is in nonblocking mode.`