diff options
Diffstat (limited to 'generic/tclPipe.c')
| -rw-r--r-- | generic/tclPipe.c | 1141 |
1 files changed, 1141 insertions, 0 deletions
diff --git a/generic/tclPipe.c b/generic/tclPipe.c new file mode 100644 index 0000000..b679ec4 --- /dev/null +++ b/generic/tclPipe.c @@ -0,0 +1,1141 @@ +/* + * 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. + */ + +#include "tclInt.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. */ +TCL_DECLARE_MUTEX(pipeMutex) /* Guard access to detList. */ + +/* + * Declarations for local functions defined in this file: + */ + +static TclFile FileForRedirect(Tcl_Interp *interp, const char *spec, + int atOk, const char *arg, const char *nextArg, + int flags, int *skipPtr, int *closePtr, + int *releasePtr); + +/* + *---------------------------------------------------------------------- + * + * FileForRedirect -- + * + * This function 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 the + * interp's result. Several arguments are side-effected; see the argument + * list below for details. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static TclFile +FileForRedirect( + Tcl_Interp *interp, /* Interpreter to use for error reporting. */ + const char *spec, /* Points to character just after redirection + * character. */ + int atOK, /* Non-zero means that '@' notation can be + * used to specify a channel, zero means that + * it isn't. */ + const char *arg, /* Pointer to entire argument containing spec: + * used for error reporting. */ + const 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_Obj *msg; + + Tcl_GetChannelError(chan, &msg); + if (msg) { + Tcl_SetObjResult(interp, msg); + } else { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "channel \"%s\" wasn't opened for %s", + Tcl_GetChannelName(chan), + ((writing) ? "writing" : "reading"))); + Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC", + "BADCHAN", 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 { + const 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) { + return NULL; + } + file = TclpOpenFile(name, flags); + Tcl_DStringFree(&nameString); + if (file == NULL) { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "couldn't %s file \"%s\": %s", + (writing ? "write" : "read"), spec, + Tcl_PosixError(interp))); + return NULL; + } + *closePtr = 1; + } + return file; + + badLastArg: + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "can't specify \"%s\" as last word in command", arg)); + Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC", "SYNTAX", NULL); + return NULL; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_DetachPids -- + * + * This function 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( + 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; + + Tcl_MutexLock(&pipeMutex); + for (i = 0; i < numPids; i++) { + detPtr = ckalloc(sizeof(Detached)); + detPtr->pid = pidPtr[i]; + detPtr->nextPtr = detList; + detList = detPtr; + } + Tcl_MutexUnlock(&pipeMutex); + +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_ReapDetachedProcs -- + * + * This function 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(void) +{ + register Detached *detPtr; + Detached *nextPtr, *prevPtr; + int status; + Tcl_Pid pid; + + Tcl_MutexLock(&pipeMutex); + 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(detPtr); + detPtr = nextPtr; + } + Tcl_MutexUnlock(&pipeMutex); +} + +/* + *---------------------------------------------------------------------- + * + * TclCleanupChildren -- + * + * This is a utility function 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 the interp's result. + * + * Side effects: + * If the last character of the interp's 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( + 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; + int waitStatus; + const char *msg; + unsigned long resolvedPid; + + abnormalExit = 0; + for (i = 0; i < numPids; i++) { + /* + * We need to get the resolved pid before we wait on it as the windows + * implementation of Tcl_WaitPid deletes the information such that any + * following calls to TclpGetPid fail. + */ + + resolvedPid = TclpGetPid(pidPtr[i]); + pid = Tcl_WaitPid(pidPtr[i], &waitStatus, 0); + if (pid == (Tcl_Pid) -1) { + result = TCL_ERROR; + if (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_SetObjResult(interp, Tcl_ObjPrintf( + "error waiting for process to exit: %s", msg)); + } + 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[TCL_INTEGER_SPACE], msg2[TCL_INTEGER_SPACE]; + + result = TCL_ERROR; + sprintf(msg1, "%lu", resolvedPid); + if (WIFEXITED(waitStatus)) { + if (interp != NULL) { + sprintf(msg2, "%u", WEXITSTATUS(waitStatus)); + Tcl_SetErrorCode(interp, "CHILDSTATUS", msg1, msg2, NULL); + } + abnormalExit = 1; + } else if (interp != NULL) { + const char *p; + + if (WIFSIGNALED(waitStatus)) { + p = Tcl_SignalMsg(WTERMSIG(waitStatus)); + Tcl_SetErrorCode(interp, "CHILDKILLED", msg1, + Tcl_SignalId(WTERMSIG(waitStatus)), p, NULL); + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "child killed: %s\n", p)); + } else if (WIFSTOPPED(waitStatus)) { + p = Tcl_SignalMsg(WSTOPSIG(waitStatus)); + Tcl_SetErrorCode(interp, "CHILDSUSP", msg1, + Tcl_SignalId(WSTOPSIG(waitStatus)), p, NULL); + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "child suspended: %s\n", p)); + } else { + Tcl_SetObjResult(interp, Tcl_NewStringObj( + "child wait status didn't make sense\n", -1)); + Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC", + "ODDWAITRESULT", msg1, 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. + */ + + if (interp != NULL) { + int count; + Tcl_Obj *objPtr; + + Tcl_Seek(errorChan, (Tcl_WideInt)0, SEEK_SET); + objPtr = Tcl_NewObj(); + count = Tcl_ReadChars(errorChan, objPtr, -1, 0); + if (count < 0) { + result = TCL_ERROR; + Tcl_DecrRefCount(objPtr); + Tcl_ResetResult(interp); + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "error reading stderr output file: %s", + Tcl_PosixError(interp))); + } else if (count > 0) { + anyErrorInfo = 1; + Tcl_SetObjResult(interp, objPtr); + result = TCL_ERROR; + } else { + Tcl_DecrRefCount(objPtr); + } + } + Tcl_Close(NULL, errorChan); + } + + /* + * If a child exited abnormally but didn't output any error information at + * all, generate an error message here. + */ + + if ((abnormalExit != 0) && (anyErrorInfo == 0) && (interp != NULL)) { + Tcl_SetObjResult(interp, Tcl_NewStringObj( + "child process exited abnormally", -1)); + } + return result; +} + +/* + *---------------------------------------------------------------------- + * + * TclCreatePipeline -- + * + * Given an argc/argv array, instantiate a pipeline of processes as + * described by the argv. + * + * This function 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( + Tcl_Interp *interp, /* Interpreter to use for error reporting. */ + int argc, /* Number of entries in argv. */ + const 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. */ + const 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; + const char *p; + const char *nextArg; + int skip, lastBar, lastArg, i, j, atOK, flags, needCmd, errorToOutput = 0; + 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; + needCmd = 1; + for (i = 0; i < argc; i++) { + errorToOutput = 0; + skip = 0; + p = argv[i]; + switch (*p++) { + case '|': + if (*p == '&') { + p++; + } + if (*p == '\0') { + if ((i == (lastBar + 1)) || (i == (argc - 1))) { + Tcl_SetObjResult(interp, Tcl_NewStringObj( + "illegal use of | or |& in command", -1)); + Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC", + "PIPESYNTAX", NULL); + goto error; + } + } + lastBar = i; + cmdCount++; + needCmd = 1; + 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 = ((i + 1) == argc) ? NULL : argv[i + 1]; + if (inputLiteral == NULL) { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "can't specify \"%s\" as last word in command", + argv[i])); + Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC", + "PIPESYNTAX", NULL); + goto error; + } + skip = 2; + } + } else { + nextArg = ((i + 1) == argc) ? NULL : argv[i + 1]; + inputLiteral = NULL; + inputFile = FileForRedirect(interp, p, 1, argv[i], nextArg, + O_RDONLY, &skip, &inputClose, &inputRelease); + if (inputFile == NULL) { + goto error; + } + } + break; + + case '>': + atOK = 1; + flags = O_WRONLY | O_CREAT | O_TRUNC; + if (*p == '>') { + p++; + atOK = 0; + + /* + * Note that the O_APPEND flag only has an effect on POSIX + * platforms. On Windows, we just have to carry on regardless. + */ + + flags = O_WRONLY | O_CREAT | O_APPEND; + } + 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); + } + } + nextArg = ((i + 1) == argc) ? NULL : argv[i + 1]; + outputFile = FileForRedirect(interp, p, atOK, argv[i], nextArg, + 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; + + /* + * Note that the O_APPEND flag only has an effect on POSIX + * platforms. On Windows, we just have to carry on regardless. + */ + + flags = O_WRONLY | O_CREAT | O_APPEND; + } + if (errorClose != 0) { + errorClose = 0; + TclpCloseFile(errorFile); + } + if (errorRelease != 0) { + errorRelease = 0; + TclpReleaseFile(errorFile); + } + if (atOK && p[0] == '@' && p[1] == '1' && p[2] == '\0') { + /* + * Special case handling of 2>@1 to redirect stderr to the + * exec/open output pipe as well. This is meant for the end of + * the command string, otherwise use |& between commands. + */ + + if (i != argc-1) { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "must specify \"%s\" as last word in command", + argv[i])); + Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC", + "PIPESYNTAX", NULL); + goto error; + } + errorFile = outputFile; + errorToOutput = 2; + skip = 1; + } else { + nextArg = ((i + 1) == argc) ? NULL : argv[i + 1]; + errorFile = FileForRedirect(interp, p, atOK, argv[i], + nextArg, flags, &skip, &errorClose, &errorRelease); + if (errorFile == NULL) { + goto error; + } + } + break; + + default: + /* + * Got a command word, not a redirection. + */ + + needCmd = 0; + break; + } + + if (skip != 0) { + for (j = i + skip; j < argc; j++) { + argv[j - skip] = argv[j]; + } + argc -= skip; + i -= 1; + } + } + + if (needCmd) { + /* + * We had a bar followed only by redirections. + */ + + Tcl_SetObjResult(interp, Tcl_NewStringObj( + "illegal use of | or |& in command", -1)); + Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC", "PIPESYNTAX", + NULL); + goto error; + } + + 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); + if (inputFile == NULL) { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "couldn't create input file for command: %s", + Tcl_PosixError(interp))); + 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_SetObjResult(interp, Tcl_ObjPrintf( + "couldn't create input pipe for command: %s", + Tcl_PosixError(interp))); + 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_SetObjResult(interp, Tcl_ObjPrintf( + "couldn't create output pipe for command: %s", + Tcl_PosixError(interp))); + 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 (errorToOutput == 2) { + /* + * Handle 2>@1 special case at end of cmd line. + */ + + errorFile = outputFile; + } else 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); + if (errorFile == NULL) { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "couldn't create error file for command: %s", + Tcl_PosixError(interp))); + 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 = ckalloc(cmdCount * sizeof(Tcl_Pid)); + + curInFile = inputFile; + + for (i = 0; i < argc; i = lastArg + 1) { + int result, joinThisError; + Tcl_Pid pid; + const char *oldName; + + /* + * Convert the program name into native form. + */ + + if (Tcl_TranslateFileName(interp, argv[i], &execBuffer) == 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] != '|') { + continue; + } + if (argv[lastArg][1] == '\0') { + break; + } + if ((argv[lastArg][1] == '&') && (argv[lastArg][2] == '\0')) { + joinThisError = 1; + break; + } + } + + /* + * 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 { + argv[lastArg] = NULL; + if (TclpCreatePipe(&pipeIn, &curOutFile) == 0) { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "couldn't create pipe: %s", Tcl_PosixError(interp))); + goto error; + } + } + + if (joinThisError != 0) { + curErrFile = curOutFile; + } else { + curErrFile = errorFile; + } + + /* + * Restore argv[i], since a caller wouldn't expect the contents of + * argv to be modified. + */ + + oldName = argv[i]; + argv[i] = Tcl_DStringValue(&execBuffer); + result = TclpCreateProcess(interp, lastArg - i, argv + i, + curInFile, curOutFile, curErrFile, &pid); + argv[i] = oldName; + if (result != 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(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( + Tcl_Interp *interp, /* Interpreter for error reporting. Can NOT be + * NULL. */ + int argc, /* How many arguments. */ + const 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_SetObjResult(interp, Tcl_NewStringObj( + "can't read output from command:" + " standard output was redirected", -1)); + Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC", + "BADREDIRECT", NULL); + goto error; + } + if ((flags & TCL_STDIN) && (inPipe == NULL)) { + Tcl_SetObjResult(interp, Tcl_NewStringObj( + "can't write input to command:" + " standard input was redirected", -1)); + Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC", + "BADREDIRECT", NULL); + goto error; + } + } + + channel = TclpCreateCommandChannel(outPipe, inPipe, errFile, + numPids, pidPtr); + + if (channel == NULL) { + Tcl_SetObjResult(interp, Tcl_NewStringObj( + "pipe for command could not be created", -1)); + Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC", "NOPIPE", NULL); + goto error; + } + return channel; + + error: + if (numPids > 0) { + Tcl_DetachPids(numPids, pidPtr); + ckfree(pidPtr); + } + if (inPipe != NULL) { + TclpCloseFile(inPipe); + } + if (outPipe != NULL) { + TclpCloseFile(outPipe); + } + if (errFile != NULL) { + TclpCloseFile(errFile); + } + return NULL; +} + +/* + * Local Variables: + * mode: c + * c-basic-offset: 4 + * fill-column: 78 + * End: + */ |