/*
* 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.
*
* RCS: @(#) $Id: tclPipe.c,v 1.19.4.1 2009/07/24 16:51:28 andreas_kupries Exp $
*/
#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, /* Intepreter 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_AppendResult(interp, "channel \"", Tcl_GetChannelName(chan),
"\" wasn't opened for ",
((writing) ? "writing" : "reading"), 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_AppendResult(interp, "couldn't ",
((writing) ? "write" : "read"), " file \"", spec, "\": ",
Tcl_PosixError(interp), NULL);
return NULL;
}
*closePtr = 1;
}
return file;
badLastArg:
Tcl_AppendResult(interp, "can't specify \"", arg,
"\" as last word in command", 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 = (Detached *) 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((char *) 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;
WAIT_STATUS_TYPE 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
* implimentation of Tcl_WaitPid deletes the information such that any
* following calls to TclpGetPid fail.
*/
resolvedPid = TclpGetPid(pidPtr[i]);
pid = Tcl_WaitPid(pidPtr[i], (int *) &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_AppendResult(interp, "error waiting for process to exit: ",
msg, 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[TCL_INTEGER_SPACE], msg2[TCL_INTEGER_SPACE];
result = TCL_ERROR;
sprintf(msg1, "%lu", resolvedPid);
if (WIFEXITED(waitStatus)) {
if (interp != (Tcl_Interp *) NULL) {
sprintf(msg2, "%lu",
(unsigned long) WEXITSTATUS(waitStatus));
Tcl_SetErrorCode(interp, "CHILDSTATUS", msg1, msg2, NULL);
}
abnormalExit = 1;
} else if (interp != NULL) {
CONST char *p;
if (WIFSIGNALED(waitStatus)) {
p = Tcl_SignalMsg((int) (WTERMSIG(waitStatus)));
Tcl_SetErrorCode(interp, "CHILDKILLED", msg1,
Tcl_SignalId((int) (WTERMSIG(waitStatus))), p,
NULL);
Tcl_AppendResult(interp, "child killed: ", p, "\n", NULL);
} else if (WIFSTOPPED(waitStatus)) {
p = Tcl_SignalMsg((int) (WSTOPSIG(waitStatus)));
Tcl_SetErrorCode(interp, "CHILDSUSP", msg1,
Tcl_SignalId((int) (WSTOPSIG(waitStatus))), p,
NULL);
Tcl_AppendResult(interp, "child suspended: ", p, "\n",
NULL);
} else {
Tcl_AppendResult(interp,
"child wait status didn't make sense\n", 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_AppendResult(interp, "error reading stderr output file: ",
Tcl_PosixError(interp), NULL);
} 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_AppendResult(interp, "child process exited abnormally", NULL);
}
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_SetResult(interp, "illegal use of | or |& in command",
TCL_STATIC);
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_AppendResult(interp, "can't specify \"", argv[i],
"\" as last word in command", 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;
flags = O_WRONLY | O_CREAT;
}
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_AppendResult(interp, "must specify \"", argv[i],
"\" as last word in command", 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_SetResult(interp,
"illegal use of | or |& in command",
TCL_STATIC);
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_AppendResult(interp,
"couldn't create input file for command: ",
Tcl_PosixError(interp), 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), 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), 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 (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_AppendResult(interp,
"couldn't create error file for command: ",
Tcl_PosixError(interp), 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 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_AppendResult(interp, "couldn't create pipe: ",
Tcl_PosixError(interp), NULL);
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((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(
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_AppendResult(interp, "can't read output from command:"
" standard output was redirected", NULL);
goto error;
}
if ((flags & TCL_STDIN) && (inPipe == NULL)) {
Tcl_AppendResult(interp, "can't write input to command:"
" standard input was redirected", 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",
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;
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/
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