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freebsd_amp_hwpstate/contrib/tcl/generic/tclPipe.c

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Import TCL release 8.0 beta 2.
1997-07-25 19:27:55 +00:00
/*
* 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;
}