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Diffstat (limited to 'generic/tclPipe.c')
| -rw-r--r-- | generic/tclPipe.c | 1051 |
1 files changed, 1051 insertions, 0 deletions
diff --git a/generic/tclPipe.c b/generic/tclPipe.c new file mode 100644 index 0000000..bf606cc --- /dev/null +++ b/generic/tclPipe.c @@ -0,0 +1,1051 @@ +/* + * tclPipe.c -- + * + * This file contains the generic portion of the command channel + * driver as well as various utility routines used in managing + * subprocesses. + * + * Copyright (c) 1997 by Sun Microsystems, Inc. + * + * See the file "license.terms" for information on usage and redistribution + * of this file, and for a DISCLAIMER OF ALL WARRANTIES. + * + * SCCS: @(#) tclPipe.c 1.8 97/06/20 13:26:45 + */ + +#include "tclInt.h" +#include "tclPort.h" + +/* + * A linked list of the following structures is used to keep track + * of child processes that have been detached but haven't exited + * yet, so we can make sure that they're properly "reaped" (officially + * waited for) and don't lie around as zombies cluttering the + * system. + */ + +typedef struct Detached { + Tcl_Pid pid; /* Id of process that's been detached + * but isn't known to have exited. */ + struct Detached *nextPtr; /* Next in list of all detached + * processes. */ +} Detached; + +static Detached *detList = NULL; /* List of all detached proceses. */ + +/* + * Declarations for local procedures defined in this file: + */ + +static TclFile FileForRedirect _ANSI_ARGS_((Tcl_Interp *interp, + char *spec, int atOk, char *arg, char *nextArg, + int flags, int *skipPtr, int *closePtr, int *releasePtr)); + +/* + *---------------------------------------------------------------------- + * + * FileForRedirect -- + * + * This procedure does much of the work of parsing redirection + * operators. It handles "@" if specified and allowed, and a file + * name, and opens the file if necessary. + * + * Results: + * The return value is the descriptor number for the file. If an + * error occurs then NULL is returned and an error message is left + * in interp->result. Several arguments are side-effected; see + * the argument list below for details. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static TclFile +FileForRedirect(interp, spec, atOK, arg, nextArg, flags, skipPtr, closePtr, + releasePtr) + Tcl_Interp *interp; /* Intepreter to use for error reporting. */ + char *spec; /* Points to character just after + * redirection character. */ + char *arg; /* Pointer to entire argument containing + * spec: used for error reporting. */ + int atOK; /* Non-zero means that '@' notation can be + * used to specify a channel, zero means that + * it isn't. */ + char *nextArg; /* Next argument in argc/argv array, if needed + * for file name or channel name. May be + * NULL. */ + int flags; /* Flags to use for opening file or to + * specify mode for channel. */ + int *skipPtr; /* Filled with 1 if redirection target was + * in spec, 2 if it was in nextArg. */ + int *closePtr; /* Filled with one if the caller should + * close the file when done with it, zero + * otherwise. */ + int *releasePtr; +{ + int writing = (flags & O_WRONLY); + Tcl_Channel chan; + TclFile file; + + *skipPtr = 1; + if ((atOK != 0) && (*spec == '@')) { + spec++; + if (*spec == '\0') { + spec = nextArg; + if (spec == NULL) { + goto badLastArg; + } + *skipPtr = 2; + } + chan = Tcl_GetChannel(interp, spec, NULL); + if (chan == (Tcl_Channel) NULL) { + return NULL; + } + file = TclpMakeFile(chan, writing ? TCL_WRITABLE : TCL_READABLE); + if (file == NULL) { + Tcl_AppendResult(interp, "channel \"", Tcl_GetChannelName(chan), + "\" wasn't opened for ", + ((writing) ? "writing" : "reading"), (char *) NULL); + return NULL; + } + *releasePtr = 1; + if (writing) { + + /* + * Be sure to flush output to the file, so that anything + * written by the child appears after stuff we've already + * written. + */ + + Tcl_Flush(chan); + } + } else { + char *name; + Tcl_DString nameString; + + if (*spec == '\0') { + spec = nextArg; + if (spec == NULL) { + goto badLastArg; + } + *skipPtr = 2; + } + name = Tcl_TranslateFileName(interp, spec, &nameString); + if (name != NULL) { + file = TclpOpenFile(name, flags); + } else { + file = NULL; + } + Tcl_DStringFree(&nameString); + if (file == NULL) { + Tcl_AppendResult(interp, "couldn't ", + ((writing) ? "write" : "read"), " file \"", spec, "\": ", + Tcl_PosixError(interp), (char *) NULL); + return NULL; + } + *closePtr = 1; + } + return file; + + badLastArg: + Tcl_AppendResult(interp, "can't specify \"", arg, + "\" as last word in command", (char *) NULL); + return NULL; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_DetachPids -- + * + * This procedure is called to indicate that one or more child + * processes have been placed in background and will never be + * waited for; they should eventually be reaped by + * Tcl_ReapDetachedProcs. + * + * Results: + * None. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_DetachPids(numPids, pidPtr) + int numPids; /* Number of pids to detach: gives size + * of array pointed to by pidPtr. */ + Tcl_Pid *pidPtr; /* Array of pids to detach. */ +{ + register Detached *detPtr; + int i; + + for (i = 0; i < numPids; i++) { + detPtr = (Detached *) ckalloc(sizeof(Detached)); + detPtr->pid = pidPtr[i]; + detPtr->nextPtr = detList; + detList = detPtr; + } +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_ReapDetachedProcs -- + * + * This procedure checks to see if any detached processes have + * exited and, if so, it "reaps" them by officially waiting on + * them. It should be called "occasionally" to make sure that + * all detached processes are eventually reaped. + * + * Results: + * None. + * + * Side effects: + * Processes are waited on, so that they can be reaped by the + * system. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_ReapDetachedProcs() +{ + register Detached *detPtr; + Detached *nextPtr, *prevPtr; + int status; + Tcl_Pid pid; + + for (detPtr = detList, prevPtr = NULL; detPtr != NULL; ) { + pid = Tcl_WaitPid(detPtr->pid, &status, WNOHANG); + if ((pid == 0) || ((pid == (Tcl_Pid) -1) && (errno != ECHILD))) { + prevPtr = detPtr; + detPtr = detPtr->nextPtr; + continue; + } + nextPtr = detPtr->nextPtr; + if (prevPtr == NULL) { + detList = detPtr->nextPtr; + } else { + prevPtr->nextPtr = detPtr->nextPtr; + } + ckfree((char *) detPtr); + detPtr = nextPtr; + } +} + +/* + *---------------------------------------------------------------------- + * + * TclCleanupChildren -- + * + * This is a utility procedure used to wait for child processes + * to exit, record information about abnormal exits, and then + * collect any stderr output generated by them. + * + * Results: + * The return value is a standard Tcl result. If anything at + * weird happened with the child processes, TCL_ERROR is returned + * and a message is left in interp->result. + * + * Side effects: + * If the last character of interp->result is a newline, then it + * is removed unless keepNewline is non-zero. File errorId gets + * closed, and pidPtr is freed back to the storage allocator. + * + *---------------------------------------------------------------------- + */ + +int +TclCleanupChildren(interp, numPids, pidPtr, errorChan) + Tcl_Interp *interp; /* Used for error messages. */ + int numPids; /* Number of entries in pidPtr array. */ + Tcl_Pid *pidPtr; /* Array of process ids of children. */ + Tcl_Channel errorChan; /* Channel for file containing stderr output + * from pipeline. NULL means there isn't any + * stderr output. */ +{ + int result = TCL_OK; + int i, abnormalExit, anyErrorInfo; + Tcl_Pid pid; + WAIT_STATUS_TYPE waitStatus; + char *msg; + + abnormalExit = 0; + for (i = 0; i < numPids; i++) { + pid = Tcl_WaitPid(pidPtr[i], (int *) &waitStatus, 0); + if (pid == (Tcl_Pid) -1) { + result = TCL_ERROR; + if (interp != (Tcl_Interp *) NULL) { + msg = Tcl_PosixError(interp); + if (errno == ECHILD) { + /* + * This changeup in message suggested by Mark Diekhans + * to remind people that ECHILD errors can occur on + * some systems if SIGCHLD isn't in its default state. + */ + + msg = + "child process lost (is SIGCHLD ignored or trapped?)"; + } + Tcl_AppendResult(interp, "error waiting for process to exit: ", + msg, (char *) NULL); + } + continue; + } + + /* + * Create error messages for unusual process exits. An + * extra newline gets appended to each error message, but + * it gets removed below (in the same fashion that an + * extra newline in the command's output is removed). + */ + + if (!WIFEXITED(waitStatus) || (WEXITSTATUS(waitStatus) != 0)) { + char msg1[20], msg2[20]; + + result = TCL_ERROR; + sprintf(msg1, "%ld", TclpGetPid(pid)); + if (WIFEXITED(waitStatus)) { + if (interp != (Tcl_Interp *) NULL) { + sprintf(msg2, "%d", WEXITSTATUS(waitStatus)); + Tcl_SetErrorCode(interp, "CHILDSTATUS", msg1, msg2, + (char *) NULL); + } + abnormalExit = 1; + } else if (WIFSIGNALED(waitStatus)) { + if (interp != (Tcl_Interp *) NULL) { + char *p; + + p = Tcl_SignalMsg((int) (WTERMSIG(waitStatus))); + Tcl_SetErrorCode(interp, "CHILDKILLED", msg1, + Tcl_SignalId((int) (WTERMSIG(waitStatus))), p, + (char *) NULL); + Tcl_AppendResult(interp, "child killed: ", p, "\n", + (char *) NULL); + } + } else if (WIFSTOPPED(waitStatus)) { + if (interp != (Tcl_Interp *) NULL) { + char *p; + + p = Tcl_SignalMsg((int) (WSTOPSIG(waitStatus))); + Tcl_SetErrorCode(interp, "CHILDSUSP", msg1, + Tcl_SignalId((int) (WSTOPSIG(waitStatus))), + p, (char *) NULL); + Tcl_AppendResult(interp, "child suspended: ", p, "\n", + (char *) NULL); + } + } else { + if (interp != (Tcl_Interp *) NULL) { + Tcl_AppendResult(interp, + "child wait status didn't make sense\n", + (char *) NULL); + } + } + } + } + + /* + * Read the standard error file. If there's anything there, + * then return an error and add the file's contents to the result + * string. + */ + + anyErrorInfo = 0; + if (errorChan != NULL) { + + /* + * Make sure we start at the beginning of the file. + */ + + Tcl_Seek(errorChan, 0L, SEEK_SET); + + if (interp != (Tcl_Interp *) NULL) { + while (1) { +#define BUFFER_SIZE 1000 + char buffer[BUFFER_SIZE+1]; + int count; + + count = Tcl_Read(errorChan, buffer, BUFFER_SIZE); + if (count == 0) { + break; + } + result = TCL_ERROR; + if (count < 0) { + Tcl_AppendResult(interp, + "error reading stderr output file: ", + Tcl_PosixError(interp), (char *) NULL); + break; /* out of the "while (1)" loop. */ + } + buffer[count] = 0; + Tcl_AppendResult(interp, buffer, (char *) NULL); + anyErrorInfo = 1; + } + } + + Tcl_Close((Tcl_Interp *) NULL, errorChan); + } + + /* + * If a child exited abnormally but didn't output any error information + * at all, generate an error message here. + */ + + if (abnormalExit && !anyErrorInfo && (interp != (Tcl_Interp *) NULL)) { + Tcl_AppendResult(interp, "child process exited abnormally", + (char *) NULL); + } + + return result; +} + +/* + *---------------------------------------------------------------------- + * + * TclCreatePipeline -- + * + * Given an argc/argv array, instantiate a pipeline of processes + * as described by the argv. + * + * This procedure is unofficially exported for use by BLT. + * + * Results: + * The return value is a count of the number of new processes + * created, or -1 if an error occurred while creating the pipeline. + * *pidArrayPtr is filled in with the address of a dynamically + * allocated array giving the ids of all of the processes. It + * is up to the caller to free this array when it isn't needed + * anymore. If inPipePtr is non-NULL, *inPipePtr is filled in + * with the file id for the input pipe for the pipeline (if any): + * the caller must eventually close this file. If outPipePtr + * isn't NULL, then *outPipePtr is filled in with the file id + * for the output pipe from the pipeline: the caller must close + * this file. If errFilePtr isn't NULL, then *errFilePtr is filled + * with a file id that may be used to read error output after the + * pipeline completes. + * + * Side effects: + * Processes and pipes are created. + * + *---------------------------------------------------------------------- + */ + +int +TclCreatePipeline(interp, argc, argv, pidArrayPtr, inPipePtr, + outPipePtr, errFilePtr) + Tcl_Interp *interp; /* Interpreter to use for error reporting. */ + int argc; /* Number of entries in argv. */ + char **argv; /* Array of strings describing commands in + * pipeline plus I/O redirection with <, + * <<, >, etc. Argv[argc] must be NULL. */ + Tcl_Pid **pidArrayPtr; /* Word at *pidArrayPtr gets filled in with + * address of array of pids for processes + * in pipeline (first pid is first process + * in pipeline). */ + TclFile *inPipePtr; /* If non-NULL, input to the pipeline comes + * from a pipe (unless overridden by + * redirection in the command). The file + * id with which to write to this pipe is + * stored at *inPipePtr. NULL means command + * specified its own input source. */ + TclFile *outPipePtr; /* If non-NULL, output to the pipeline goes + * to a pipe, unless overriden by redirection + * in the command. The file id with which to + * read frome this pipe is stored at + * *outPipePtr. NULL means command specified + * its own output sink. */ + TclFile *errFilePtr; /* If non-NULL, all stderr output from the + * pipeline will go to a temporary file + * created here, and a descriptor to read + * the file will be left at *errFilePtr. + * The file will be removed already, so + * closing this descriptor will be the end + * of the file. If this is NULL, then + * all stderr output goes to our stderr. + * If the pipeline specifies redirection + * then the file will still be created + * but it will never get any data. */ +{ + Tcl_Pid *pidPtr = NULL; /* Points to malloc-ed array holding all + * the pids of child processes. */ + int numPids; /* Actual number of processes that exist + * at *pidPtr right now. */ + int cmdCount; /* Count of number of distinct commands + * found in argc/argv. */ + char *inputLiteral = NULL; /* If non-null, then this points to a + * string containing input data (specified + * via <<) to be piped to the first process + * in the pipeline. */ + TclFile inputFile = NULL; /* If != NULL, gives file to use as input for + * first process in pipeline (specified via < + * or <@). */ + int inputClose = 0; /* If non-zero, then inputFile should be + * closed when cleaning up. */ + int inputRelease = 0; + TclFile outputFile = NULL; /* Writable file for output from last command + * in pipeline (could be file or pipe). NULL + * means use stdout. */ + int outputClose = 0; /* If non-zero, then outputFile should be + * closed when cleaning up. */ + int outputRelease = 0; + TclFile errorFile = NULL; /* Writable file for error output from all + * commands in pipeline. NULL means use + * stderr. */ + int errorClose = 0; /* If non-zero, then errorFile should be + * closed when cleaning up. */ + int errorRelease = 0; + char *p; + int skip, lastBar, lastArg, i, j, atOK, flags, errorToOutput; + Tcl_DString execBuffer; + TclFile pipeIn; + TclFile curInFile, curOutFile, curErrFile; + Tcl_Channel channel; + + if (inPipePtr != NULL) { + *inPipePtr = NULL; + } + if (outPipePtr != NULL) { + *outPipePtr = NULL; + } + if (errFilePtr != NULL) { + *errFilePtr = NULL; + } + + Tcl_DStringInit(&execBuffer); + + pipeIn = NULL; + curInFile = NULL; + curOutFile = NULL; + numPids = 0; + + /* + * First, scan through all the arguments to figure out the structure + * of the pipeline. Process all of the input and output redirection + * arguments and remove them from the argument list in the pipeline. + * Count the number of distinct processes (it's the number of "|" + * arguments plus one) but don't remove the "|" arguments because + * they'll be used in the second pass to seperate the individual + * child processes. Cannot start the child processes in this pass + * because the redirection symbols may appear anywhere in the + * command line -- e.g., the '<' that specifies the input to the + * entire pipe may appear at the very end of the argument list. + */ + + lastBar = -1; + cmdCount = 1; + for (i = 0; i < argc; i++) { + skip = 0; + p = argv[i]; + switch (*p++) { + case '|': + if (*p == '&') { + p++; + } + if (*p == '\0') { + if ((i == (lastBar + 1)) || (i == (argc - 1))) { + Tcl_SetResult(interp, + "illegal use of | or |& in command", + TCL_STATIC); + goto error; + } + } + lastBar = i; + cmdCount++; + break; + + case '<': + if (inputClose != 0) { + inputClose = 0; + TclpCloseFile(inputFile); + } + if (inputRelease != 0) { + inputRelease = 0; + TclpReleaseFile(inputFile); + } + if (*p == '<') { + inputFile = NULL; + inputLiteral = p + 1; + skip = 1; + if (*inputLiteral == '\0') { + inputLiteral = argv[i + 1]; + if (inputLiteral == NULL) { + Tcl_AppendResult(interp, "can't specify \"", argv[i], + "\" as last word in command", (char *) NULL); + goto error; + } + skip = 2; + } + } else { + inputLiteral = NULL; + inputFile = FileForRedirect(interp, p, 1, argv[i], + argv[i + 1], O_RDONLY, &skip, &inputClose, &inputRelease); + if (inputFile == NULL) { + goto error; + } + } + break; + + case '>': + atOK = 1; + flags = O_WRONLY | O_CREAT | O_TRUNC; + errorToOutput = 0; + if (*p == '>') { + p++; + atOK = 0; + flags = O_WRONLY | O_CREAT; + } + if (*p == '&') { + if (errorClose != 0) { + errorClose = 0; + TclpCloseFile(errorFile); + } + errorToOutput = 1; + p++; + } + + /* + * Close the old output file, but only if the error file is + * not also using it. + */ + + if (outputClose != 0) { + outputClose = 0; + if (errorFile == outputFile) { + errorClose = 1; + } else { + TclpCloseFile(outputFile); + } + } + if (outputRelease != 0) { + outputRelease = 0; + if (errorFile == outputFile) { + errorRelease = 1; + } else { + TclpReleaseFile(outputFile); + } + } + outputFile = FileForRedirect(interp, p, atOK, argv[i], + argv[i + 1], flags, &skip, &outputClose, &outputRelease); + if (outputFile == NULL) { + goto error; + } + if (errorToOutput) { + if (errorClose != 0) { + errorClose = 0; + TclpCloseFile(errorFile); + } + if (errorRelease != 0) { + errorRelease = 0; + TclpReleaseFile(errorFile); + } + errorFile = outputFile; + } + break; + + case '2': + if (*p != '>') { + break; + } + p++; + atOK = 1; + flags = O_WRONLY | O_CREAT | O_TRUNC; + if (*p == '>') { + p++; + atOK = 0; + flags = O_WRONLY | O_CREAT; + } + if (errorClose != 0) { + errorClose = 0; + TclpCloseFile(errorFile); + } + if (errorRelease != 0) { + errorRelease = 0; + TclpReleaseFile(errorFile); + } + errorFile = FileForRedirect(interp, p, atOK, argv[i], + argv[i + 1], flags, &skip, &errorClose, &errorRelease); + if (errorFile == NULL) { + goto error; + } + break; + } + + if (skip != 0) { + for (j = i + skip; j < argc; j++) { + argv[j - skip] = argv[j]; + } + argc -= skip; + i -= 1; + } + } + + if (inputFile == NULL) { + if (inputLiteral != NULL) { + /* + * The input for the first process is immediate data coming from + * Tcl. Create a temporary file for it and put the data into the + * file. + */ + inputFile = TclpCreateTempFile(inputLiteral, NULL); + if (inputFile == NULL) { + Tcl_AppendResult(interp, + "couldn't create input file for command: ", + Tcl_PosixError(interp), (char *) NULL); + goto error; + } + inputClose = 1; + } else if (inPipePtr != NULL) { + /* + * The input for the first process in the pipeline is to + * come from a pipe that can be written from by the caller. + */ + + if (TclpCreatePipe(&inputFile, inPipePtr) == 0) { + Tcl_AppendResult(interp, + "couldn't create input pipe for command: ", + Tcl_PosixError(interp), (char *) NULL); + goto error; + } + inputClose = 1; + } else { + /* + * The input for the first process comes from stdin. + */ + + channel = Tcl_GetStdChannel(TCL_STDIN); + if (channel != NULL) { + inputFile = TclpMakeFile(channel, TCL_READABLE); + if (inputFile != NULL) { + inputRelease = 1; + } + } + } + } + + if (outputFile == NULL) { + if (outPipePtr != NULL) { + /* + * Output from the last process in the pipeline is to go to a + * pipe that can be read by the caller. + */ + + if (TclpCreatePipe(outPipePtr, &outputFile) == 0) { + Tcl_AppendResult(interp, + "couldn't create output pipe for command: ", + Tcl_PosixError(interp), (char *) NULL); + goto error; + } + outputClose = 1; + } else { + /* + * The output for the last process goes to stdout. + */ + + channel = Tcl_GetStdChannel(TCL_STDOUT); + if (channel) { + outputFile = TclpMakeFile(channel, TCL_WRITABLE); + if (outputFile != NULL) { + outputRelease = 1; + } + } + } + } + + if (errorFile == NULL) { + if (errFilePtr != NULL) { + /* + * Set up the standard error output sink for the pipeline, if + * requested. Use a temporary file which is opened, then deleted. + * Could potentially just use pipe, but if it filled up it could + * cause the pipeline to deadlock: we'd be waiting for processes + * to complete before reading stderr, and processes couldn't + * complete because stderr was backed up. + */ + + errorFile = TclpCreateTempFile(NULL, NULL); + if (errorFile == NULL) { + Tcl_AppendResult(interp, + "couldn't create error file for command: ", + Tcl_PosixError(interp), (char *) NULL); + goto error; + } + *errFilePtr = errorFile; + } else { + /* + * Errors from the pipeline go to stderr. + */ + + channel = Tcl_GetStdChannel(TCL_STDERR); + if (channel) { + errorFile = TclpMakeFile(channel, TCL_WRITABLE); + if (errorFile != NULL) { + errorRelease = 1; + } + } + } + } + + /* + * Scan through the argc array, creating a process for each + * group of arguments between the "|" characters. + */ + + Tcl_ReapDetachedProcs(); + pidPtr = (Tcl_Pid *) ckalloc((unsigned) (cmdCount * sizeof(Tcl_Pid))); + + curInFile = inputFile; + + for (i = 0; i < argc; i = lastArg + 1) { + int joinThisError; + Tcl_Pid pid; + + /* + * Convert the program name into native form. + */ + + argv[i] = Tcl_TranslateFileName(interp, argv[i], &execBuffer); + if (argv[i] == NULL) { + goto error; + } + + /* + * Find the end of the current segment of the pipeline. + */ + + joinThisError = 0; + for (lastArg = i; lastArg < argc; lastArg++) { + if (argv[lastArg][0] == '|') { + if (argv[lastArg][1] == '\0') { + break; + } + if ((argv[lastArg][1] == '&') && (argv[lastArg][2] == '\0')) { + joinThisError = 1; + break; + } + } + } + argv[lastArg] = NULL; + + /* + * If this is the last segment, use the specified outputFile. + * Otherwise create an intermediate pipe. pipeIn will become the + * curInFile for the next segment of the pipe. + */ + + if (lastArg == argc) { + curOutFile = outputFile; + } else { + if (TclpCreatePipe(&pipeIn, &curOutFile) == 0) { + Tcl_AppendResult(interp, "couldn't create pipe: ", + Tcl_PosixError(interp), (char *) NULL); + goto error; + } + } + + if (joinThisError != 0) { + curErrFile = curOutFile; + } else { + curErrFile = errorFile; + } + + if (TclpCreateProcess(interp, lastArg - i, argv + i, + curInFile, curOutFile, curErrFile, &pid) != TCL_OK) { + goto error; + } + Tcl_DStringFree(&execBuffer); + + pidPtr[numPids] = pid; + numPids++; + + /* + * Close off our copies of file descriptors that were set up for + * this child, then set up the input for the next child. + */ + + if ((curInFile != NULL) && (curInFile != inputFile)) { + TclpCloseFile(curInFile); + } + curInFile = pipeIn; + pipeIn = NULL; + + if ((curOutFile != NULL) && (curOutFile != outputFile)) { + TclpCloseFile(curOutFile); + } + curOutFile = NULL; + } + + *pidArrayPtr = pidPtr; + + /* + * All done. Cleanup open files lying around and then return. + */ + +cleanup: + Tcl_DStringFree(&execBuffer); + + if (inputClose) { + TclpCloseFile(inputFile); + } else if (inputRelease) { + TclpReleaseFile(inputFile); + } + if (outputClose) { + TclpCloseFile(outputFile); + } else if (outputRelease) { + TclpReleaseFile(outputFile); + } + if (errorClose) { + TclpCloseFile(errorFile); + } else if (errorRelease) { + TclpReleaseFile(errorFile); + } + return numPids; + + /* + * An error occurred. There could have been extra files open, such + * as pipes between children. Clean them all up. Detach any child + * processes that have been created. + */ + +error: + if (pipeIn != NULL) { + TclpCloseFile(pipeIn); + } + if ((curOutFile != NULL) && (curOutFile != outputFile)) { + TclpCloseFile(curOutFile); + } + if ((curInFile != NULL) && (curInFile != inputFile)) { + TclpCloseFile(curInFile); + } + if ((inPipePtr != NULL) && (*inPipePtr != NULL)) { + TclpCloseFile(*inPipePtr); + *inPipePtr = NULL; + } + if ((outPipePtr != NULL) && (*outPipePtr != NULL)) { + TclpCloseFile(*outPipePtr); + *outPipePtr = NULL; + } + if ((errFilePtr != NULL) && (*errFilePtr != NULL)) { + TclpCloseFile(*errFilePtr); + *errFilePtr = NULL; + } + if (pidPtr != NULL) { + for (i = 0; i < numPids; i++) { + if (pidPtr[i] != (Tcl_Pid) -1) { + Tcl_DetachPids(1, &pidPtr[i]); + } + } + ckfree((char *) pidPtr); + } + numPids = -1; + goto cleanup; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_OpenCommandChannel -- + * + * Opens an I/O channel to one or more subprocesses specified + * by argc and argv. The flags argument determines the + * disposition of the stdio handles. If the TCL_STDIN flag is + * set then the standard input for the first subprocess will + * be tied to the channel: writing to the channel will provide + * input to the subprocess. If TCL_STDIN is not set, then + * standard input for the first subprocess will be the same as + * this application's standard input. If TCL_STDOUT is set then + * standard output from the last subprocess can be read from the + * channel; otherwise it goes to this application's standard + * output. If TCL_STDERR is set, standard error output for all + * subprocesses is returned to the channel and results in an error + * when the channel is closed; otherwise it goes to this + * application's standard error. If TCL_ENFORCE_MODE is not set, + * then argc and argv can redirect the stdio handles to override + * TCL_STDIN, TCL_STDOUT, and TCL_STDERR; if it is set, then it + * is an error for argc and argv to override stdio channels for + * which TCL_STDIN, TCL_STDOUT, and TCL_STDERR have been set. + * + * Results: + * A new command channel, or NULL on failure with an error + * message left in interp. + * + * Side effects: + * Creates processes, opens pipes. + * + *---------------------------------------------------------------------- + */ + +Tcl_Channel +Tcl_OpenCommandChannel(interp, argc, argv, flags) + Tcl_Interp *interp; /* Interpreter for error reporting. Can + * NOT be NULL. */ + int argc; /* How many arguments. */ + char **argv; /* Array of arguments for command pipe. */ + int flags; /* Or'ed combination of TCL_STDIN, TCL_STDOUT, + * TCL_STDERR, and TCL_ENFORCE_MODE. */ +{ + TclFile *inPipePtr, *outPipePtr, *errFilePtr; + TclFile inPipe, outPipe, errFile; + int numPids; + Tcl_Pid *pidPtr; + Tcl_Channel channel; + + inPipe = outPipe = errFile = NULL; + + inPipePtr = (flags & TCL_STDIN) ? &inPipe : NULL; + outPipePtr = (flags & TCL_STDOUT) ? &outPipe : NULL; + errFilePtr = (flags & TCL_STDERR) ? &errFile : NULL; + + numPids = TclCreatePipeline(interp, argc, argv, &pidPtr, inPipePtr, + outPipePtr, errFilePtr); + + if (numPids < 0) { + goto error; + } + + /* + * Verify that the pipes that were created satisfy the + * readable/writable constraints. + */ + + if (flags & TCL_ENFORCE_MODE) { + if ((flags & TCL_STDOUT) && (outPipe == NULL)) { + Tcl_AppendResult(interp, "can't read output from command:", + " standard output was redirected", (char *) NULL); + goto error; + } + if ((flags & TCL_STDIN) && (inPipe == NULL)) { + Tcl_AppendResult(interp, "can't write input to command:", + " standard input was redirected", (char *) NULL); + goto error; + } + } + + channel = TclpCreateCommandChannel(outPipe, inPipe, errFile, + numPids, pidPtr); + + if (channel == (Tcl_Channel) NULL) { + Tcl_AppendResult(interp, "pipe for command could not be created", + (char *) NULL); + goto error; + } + return channel; + +error: + if (numPids > 0) { + Tcl_DetachPids(numPids, pidPtr); + ckfree((char *) pidPtr); + } + if (inPipe != NULL) { + TclpCloseFile(inPipe); + } + if (outPipe != NULL) { + TclpCloseFile(outPipe); + } + if (errFile != NULL) { + TclpCloseFile(errFile); + } + return NULL; +} |