tclUnixPipe.c Go to the documentation of this file. /* * tclUnixPipe.c -- * * This file implements the UNIX-specific exec pipeline functions, the * "pipe" channel driver, and the "pid" Tcl command. * * Copyright (c) 1991-1994 The Regents of the University of California. * Copyright (c) 1994-1997 Sun Microsystems, Inc. * * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. * * RCS: @(#) $Id: tclUnixPipe.c,v 1.40 2007/12/13 15:28:42 dgp Exp $ */ #include "tclInt.h" #ifdef USE_VFORK #define fork vfork #endif /* * The following macros convert between TclFile's and fd's. The conversion * simple involves shifting fd's up by one to ensure that no valid fd is ever * the same as NULL. */ #define MakeFile(fd) ((TclFile)INT2PTR(((int)(fd))+1)) #define GetFd(file) (PTR2INT(file)-1) /* * This structure describes per-instance state of a pipe based channel. */ typedef struct PipeState { Tcl_Channel channel; /* Channel associated with this file. */ TclFile inFile; /* Output from pipe. */ TclFile outFile; /* Input to pipe. */ TclFile errorFile; /* Error output from pipe. */ int numPids; /* How many processes are attached to this * pipe? */ Tcl_Pid *pidPtr; /* The process IDs themselves. Allocated by * the creator of the pipe. */ int isNonBlocking; /* Nonzero when the pipe is in nonblocking * mode. Used to decide whether to wait for * the children at close time. */ } PipeState; /* * Declarations for local functions defined in this file: */ static int PipeBlockModeProc(ClientData instanceData, int mode); static int PipeCloseProc(ClientData instanceData, Tcl_Interp *interp); static int PipeGetHandleProc(ClientData instanceData, int direction, ClientData *handlePtr); static int PipeInputProc(ClientData instanceData, char *buf, int toRead, int *errorCode); static int PipeOutputProc(ClientData instanceData, const char *buf, int toWrite, int *errorCode); static void PipeWatchProc(ClientData instanceData, int mask); static void RestoreSignals(void); static int SetupStdFile(TclFile file, int type); /* * This structure describes the channel type structure for command pipe based * I/O: */ static Tcl_ChannelType pipeChannelType = { "pipe", /* Type name. */ TCL_CHANNEL_VERSION_5, /* v5 channel */ PipeCloseProc, /* Close proc. */ PipeInputProc, /* Input proc. */ PipeOutputProc, /* Output proc. */ NULL, /* Seek proc. */ NULL, /* Set option proc. */ NULL, /* Get option proc. */ PipeWatchProc, /* Initialize notifier. */ PipeGetHandleProc, /* Get OS handles out of channel. */ NULL, /* close2proc. */ PipeBlockModeProc, /* Set blocking or non-blocking mode.*/ NULL, /* flush proc. */ NULL, /* handler proc. */ NULL, /* wide seek proc */ NULL, /* thread action proc */ NULL, /* truncation */ };  /* *---------------------------------------------------------------------- * * TclpMakeFile -- * * Make a TclFile from a channel. * * Results: * Returns a new TclFile or NULL on failure. * * Side effects: * None. * *---------------------------------------------------------------------- */ TclFile TclpMakeFile( Tcl_Channel channel, /* Channel to get file from. */ int direction) /* Either TCL_READABLE or TCL_WRITABLE. */ { ClientData data; if (Tcl_GetChannelHandle(channel, direction, (ClientData *) &data) == TCL_OK) { return MakeFile(PTR2INT(data)); } else { return (TclFile) NULL; } }  /* *---------------------------------------------------------------------- * * TclpOpenFile -- * * Open a file for use in a pipeline. * * Results: * Returns a new TclFile handle or NULL on failure. * * Side effects: * May cause a file to be created on the file system. * *---------------------------------------------------------------------- */ TclFile TclpOpenFile( const char *fname, /* The name of the file to open. */ int mode) /* In what mode to open the file? */ { int fd; const char *native; Tcl_DString ds; native = Tcl_UtfToExternalDString(NULL, fname, -1, &ds); fd = TclOSopen(native, mode, 0666); /* INTL: Native. */ Tcl_DStringFree(&ds); if (fd != -1) { fcntl(fd, F_SETFD, FD_CLOEXEC); /* * If the file is being opened for writing, seek to the end so we can * append to any data already in the file. */ if ((mode & O_WRONLY) && !(mode & O_APPEND)) { TclOSseek(fd, (Tcl_SeekOffset) 0, SEEK_END); } /* * Increment the fd so it can't be 0, which would conflict with the * NULL return for errors. */ return MakeFile(fd); } return NULL; }  /* *---------------------------------------------------------------------- * * TclpCreateTempFile -- * * This function creates a temporary file initialized with an optional * string, and returns a file handle with the file pointer at the * beginning of the file. * * Results: * A handle to a file. * * Side effects: * None. * *---------------------------------------------------------------------- */ TclFile TclpCreateTempFile( const char *contents) /* String to write into temp file, or NULL. */ { char fileName[L_tmpnam + 9]; const char *native; Tcl_DString dstring; int fd; /* * We should also check against making more then TMP_MAX of these. */ strcpy(fileName, P_tmpdir); /* INTL: Native. */ if (fileName[strlen(fileName) - 1] != '/') { strcat(fileName, "/"); /* INTL: Native. */ } strcat(fileName, "tclXXXXXX"); fd = mkstemp(fileName); /* INTL: Native. */ if (fd == -1) { return NULL; } fcntl(fd, F_SETFD, FD_CLOEXEC); unlink(fileName); /* INTL: Native. */ if (contents != NULL) { native = Tcl_UtfToExternalDString(NULL, contents, -1, &dstring); if (write(fd, native, strlen(native)) == -1) { close(fd); Tcl_DStringFree(&dstring); return NULL; } Tcl_DStringFree(&dstring); TclOSseek(fd, (Tcl_SeekOffset) 0, SEEK_SET); } return MakeFile(fd); }  /* *---------------------------------------------------------------------- * * TclpTempFileName -- * * This function returns unique filename. * * Results: * Returns a valid Tcl_Obj* with refCount 0, or NULL on failure. * * Side effects: * None. * *---------------------------------------------------------------------- */ Tcl_Obj * TclpTempFileName(void) { char fileName[L_tmpnam + 9]; Tcl_Obj *result = NULL; int fd; /* * We should also check against making more then TMP_MAX of these. */ strcpy(fileName, P_tmpdir); /* INTL: Native. */ if (fileName[strlen(fileName) - 1] != '/') { strcat(fileName, "/"); /* INTL: Native. */ } strcat(fileName, "tclXXXXXX"); fd = mkstemp(fileName); /* INTL: Native. */ if (fd == -1) { return NULL; } fcntl(fd, F_SETFD, FD_CLOEXEC); unlink(fileName); /* INTL: Native. */ result = TclpNativeToNormalized((ClientData) fileName); close(fd); return result; }  /* *---------------------------------------------------------------------- * * TclpCreatePipe -- * * Creates a pipe - simply calls the pipe() function. * * Results: * Returns 1 on success, 0 on failure. * * Side effects: * Creates a pipe. * *---------------------------------------------------------------------- */ int TclpCreatePipe( TclFile *readPipe, /* Location to store file handle for read side * of pipe. */ TclFile *writePipe) /* Location to store file handle for write * side of pipe. */ { int pipeIds[2]; if (pipe(pipeIds) != 0) { return 0; } fcntl(pipeIds[0], F_SETFD, FD_CLOEXEC); fcntl(pipeIds[1], F_SETFD, FD_CLOEXEC); *readPipe = MakeFile(pipeIds[0]); *writePipe = MakeFile(pipeIds[1]); return 1; }  /* *---------------------------------------------------------------------- * * TclpCloseFile -- * * Implements a mechanism to close a UNIX file. * * Results: * Returns 0 on success, or -1 on error, setting errno. * * Side effects: * The file is closed. * *---------------------------------------------------------------------- */ int TclpCloseFile( TclFile file) /* The file to close. */ { int fd = GetFd(file); /* * Refuse to close the fds for stdin, stdout and stderr. */ if ((fd == 0) || (fd == 1) || (fd == 2)) { return 0; } Tcl_DeleteFileHandler(fd); return close(fd); }  /* *--------------------------------------------------------------------------- * * TclpCreateProcess -- * * Create a child process that has the specified files as its standard * input, output, and error. The child process runs asynchronously and * runs with the same environment variables as the creating process. * * The path is searched to find the specified executable. * * Results: * The return value is TCL_ERROR and an error message is left in the * interp's result if there was a problem creating the child process. * Otherwise, the return value is TCL_OK and *pidPtr is filled with the * process id of the child process. * * Side effects: * A process is created. * *--------------------------------------------------------------------------- */ /* ARGSUSED */ int TclpCreateProcess( Tcl_Interp *interp, /* Interpreter in which to leave errors that * occurred when creating the child process. * Error messages from the child process * itself are sent to errorFile. */ int argc, /* Number of arguments in following array. */ const char **argv, /* Array of argument strings in UTF-8. * argv[0] contains the name of the executable * translated using Tcl_TranslateFileName * call). Additional arguments have not been * converted. */ TclFile inputFile, /* If non-NULL, gives the file to use as input * for the child process. If inputFile file is * not readable or is NULL, the child will * receive no standard input. */ TclFile outputFile, /* If non-NULL, gives the file that receives * output from the child process. If * outputFile file is not writeable or is * NULL, output from the child will be * discarded. */ TclFile errorFile, /* If non-NULL, gives the file that receives * errors from the child process. If errorFile * file is not writeable or is NULL, errors * from the child will be discarded. errorFile * may be the same as outputFile. */ Tcl_Pid *pidPtr) /* If this function is successful, pidPtr is * filled with the process id of the child * process. */ { TclFile errPipeIn, errPipeOut; int count, status, fd; char errSpace[200 + TCL_INTEGER_SPACE]; Tcl_DString *dsArray; char **newArgv; int pid, i; errPipeIn = NULL; errPipeOut = NULL; pid = -1; /* * Create a pipe that the child can use to return error information if * anything goes wrong. */ if (TclpCreatePipe(&errPipeIn, &errPipeOut) == 0) { Tcl_AppendResult(interp, "couldn't create pipe: ", Tcl_PosixError(interp), NULL); goto error; } /* * We need to allocate and convert this before the fork so it is properly * deallocated later */ dsArray = (Tcl_DString *) TclStackAlloc(interp, argc * sizeof(Tcl_DString)); newArgv = (char **) TclStackAlloc(interp, (argc+1) * sizeof(char *)); newArgv[argc] = NULL; for (i = 0; i < argc; i++) { newArgv[i] = Tcl_UtfToExternalDString(NULL, argv[i], -1, &dsArray[i]); } #ifdef USE_VFORK /* * After vfork(), do not call code in the child that changes global state, * because it is using the parent's memory space at that point and writes * might corrupt the parent: so ensure standard channels are initialized in * the parent, otherwise SetupStdFile() might initialize them in the child. */ if (!inputFile) { Tcl_GetStdChannel(TCL_STDIN); } if (!outputFile) { Tcl_GetStdChannel(TCL_STDOUT); } if (!errorFile) { Tcl_GetStdChannel(TCL_STDERR); } #endif pid = fork(); if (pid == 0) { int joinThisError = errorFile && (errorFile == outputFile); fd = GetFd(errPipeOut); /* * Set up stdio file handles for the child process. */ if (!SetupStdFile(inputFile, TCL_STDIN) || !SetupStdFile(outputFile, TCL_STDOUT) || (!joinThisError && !SetupStdFile(errorFile, TCL_STDERR)) || (joinThisError && ((dup2(1,2) == -1) || (fcntl(2, F_SETFD, 0) != 0)))) { sprintf(errSpace, "%dforked process couldn't set up input/output: ", errno); write(fd, errSpace, (size_t) strlen(errSpace)); _exit(1); } /* * Close the input side of the error pipe. */ RestoreSignals(); execvp(newArgv[0], newArgv); /* INTL: Native. */ sprintf(errSpace, "%dcouldn't execute \"%.150s\": ", errno, argv[0]); write(fd, errSpace, (size_t) strlen(errSpace)); _exit(1); } /* * Free the mem we used for the fork */ for (i = 0; i < argc; i++) { Tcl_DStringFree(&dsArray[i]); } TclStackFree(interp, newArgv); TclStackFree(interp, dsArray); if (pid == -1) { Tcl_AppendResult(interp, "couldn't fork child process: ", Tcl_PosixError(interp), NULL); goto error; } /* * Read back from the error pipe to see if the child started up OK. The * info in the pipe (if any) consists of a decimal errno value followed by * an error message. */ TclpCloseFile(errPipeOut); errPipeOut = NULL; fd = GetFd(errPipeIn); count = read(fd, errSpace, (size_t) (sizeof(errSpace) - 1)); if (count > 0) { char *end; errSpace[count] = 0; errno = strtol(errSpace, &end, 10); Tcl_AppendResult(interp, end, Tcl_PosixError(interp), NULL); goto error; } TclpCloseFile(errPipeIn); *pidPtr = (Tcl_Pid) INT2PTR(pid); return TCL_OK; error: if (pid != -1) { /* * Reap the child process now if an error occurred during its startup. * We don't call this with WNOHANG because that can lead to defunct * processes on an MP system. We shouldn't have to worry about hanging * here, since this is the error case. [Bug: 6148] */ Tcl_WaitPid((Tcl_Pid) INT2PTR(pid), &status, 0); } if (errPipeIn) { TclpCloseFile(errPipeIn); } if (errPipeOut) { TclpCloseFile(errPipeOut); } return TCL_ERROR; }  /* *---------------------------------------------------------------------- * * RestoreSignals -- * * This function is invoked in a forked child process just before * exec-ing a new program to restore all signals to their default * settings. * * Results: * None. * * Side effects: * Signal settings get changed. * *---------------------------------------------------------------------- */ static void RestoreSignals(void) { #ifdef SIGABRT signal(SIGABRT, SIG_DFL); #endif #ifdef SIGALRM signal(SIGALRM, SIG_DFL); #endif #ifdef SIGFPE signal(SIGFPE, SIG_DFL); #endif #ifdef SIGHUP signal(SIGHUP, SIG_DFL); #endif #ifdef SIGILL signal(SIGILL, SIG_DFL); #endif #ifdef SIGINT signal(SIGINT, SIG_DFL); #endif #ifdef SIGPIPE signal(SIGPIPE, SIG_DFL); #endif #ifdef SIGQUIT signal(SIGQUIT, SIG_DFL); #endif #ifdef SIGSEGV signal(SIGSEGV, SIG_DFL); #endif #ifdef SIGTERM signal(SIGTERM, SIG_DFL); #endif #ifdef SIGUSR1 signal(SIGUSR1, SIG_DFL); #endif #ifdef SIGUSR2 signal(SIGUSR2, SIG_DFL); #endif #ifdef SIGCHLD signal(SIGCHLD, SIG_DFL); #endif #ifdef SIGCONT signal(SIGCONT, SIG_DFL); #endif #ifdef SIGTSTP signal(SIGTSTP, SIG_DFL); #endif #ifdef SIGTTIN signal(SIGTTIN, SIG_DFL); #endif #ifdef SIGTTOU signal(SIGTTOU, SIG_DFL); #endif }  /* *---------------------------------------------------------------------- * * SetupStdFile -- * * Set up stdio file handles for the child process, using the current * standard channels if no other files are specified. If no standard * channel is defined, or if no file is associated with the channel, then * the corresponding standard fd is closed. * * Results: * Returns 1 on success, or 0 on failure. * * Side effects: * Replaces stdio fds. * *---------------------------------------------------------------------- */ static int SetupStdFile( TclFile file, /* File to dup, or NULL. */ int type) /* One of TCL_STDIN, TCL_STDOUT, TCL_STDERR */ { Tcl_Channel channel; int fd; int targetFd = 0; /* Initializations here needed only to */ int direction = 0; /* prevent warnings about using uninitialized * variables. */ switch (type) { case TCL_STDIN: targetFd = 0; direction = TCL_READABLE; break; case TCL_STDOUT: targetFd = 1; direction = TCL_WRITABLE; break; case TCL_STDERR: targetFd = 2; direction = TCL_WRITABLE; break; } if (!file) { channel = Tcl_GetStdChannel(type); if (channel) { file = TclpMakeFile(channel, direction); } } if (file) { fd = GetFd(file); if (fd != targetFd) { if (dup2(fd, targetFd) == -1) { return 0; } /* * Must clear the close-on-exec flag for the target FD, since some * systems (e.g. Ultrix) do not clear the CLOEXEC flag on the * target FD. */ fcntl(targetFd, F_SETFD, 0); } else { /* * Since we aren't dup'ing the file, we need to explicitly clear * the close-on-exec flag. */ fcntl(fd, F_SETFD, 0); } } else { close(targetFd); } return 1; }  /* *---------------------------------------------------------------------- * * TclpCreateCommandChannel -- * * This function is called by the generic IO level to perform the * platform specific channel initialization for a command channel. * * Results: * Returns a new channel or NULL on failure. * * Side effects: * Allocates a new channel. * *---------------------------------------------------------------------- */ Tcl_Channel TclpCreateCommandChannel( TclFile readFile, /* If non-null, gives the file for reading. */ TclFile writeFile, /* If non-null, gives the file for writing. */ TclFile errorFile, /* If non-null, gives the file where errors * can be read. */ int numPids, /* The number of pids in the pid array. */ Tcl_Pid *pidPtr) /* An array of process identifiers. Allocated * by the caller, freed when the channel is * closed or the processes are detached (in a * background exec). */ { char channelName[16 + TCL_INTEGER_SPACE]; int channelId; PipeState *statePtr = (PipeState *) ckalloc((unsigned) sizeof(PipeState)); int mode; statePtr->inFile = readFile; statePtr->outFile = writeFile; statePtr->errorFile = errorFile; statePtr->numPids = numPids; statePtr->pidPtr = pidPtr; statePtr->isNonBlocking = 0; mode = 0; if (readFile) { mode |= TCL_READABLE; } if (writeFile) { mode |= TCL_WRITABLE; } /* * Use one of the fds associated with the channel as the channel id. */ if (readFile) { channelId = GetFd(readFile); } else if (writeFile) { channelId = GetFd(writeFile); } else if (errorFile) { channelId = GetFd(errorFile); } else { channelId = 0; } /* * For backward compatibility with previous versions of Tcl, we use * "file%d" as the base name for pipes even though it would be more * natural to use "pipe%d". */ sprintf(channelName, "file%d", channelId); statePtr->channel = Tcl_CreateChannel(&pipeChannelType, channelName, (ClientData) statePtr, mode); return statePtr->channel; }  /* *---------------------------------------------------------------------- * * TclGetAndDetachPids -- * * This function is invoked in the generic implementation of a * background "exec" (an exec when invoked with a terminating "&") to * store a list of the PIDs for processes in a command pipeline in the * interp's result and to detach the processes. * * Results: * None. * * Side effects: * Modifies the interp's result. Detaches processes. * *---------------------------------------------------------------------- */ void TclGetAndDetachPids( Tcl_Interp *interp, /* Interpreter to append the PIDs to. */ Tcl_Channel chan) /* Handle for the pipeline. */ { PipeState *pipePtr; const Tcl_ChannelType *chanTypePtr; int i; char buf[TCL_INTEGER_SPACE]; /* * Punt if the channel is not a command channel. */ chanTypePtr = Tcl_GetChannelType(chan); if (chanTypePtr != &pipeChannelType) { return; } pipePtr = (PipeState *) Tcl_GetChannelInstanceData(chan); for (i = 0; i < pipePtr->numPids; i++) { TclFormatInt(buf, (long) TclpGetPid(pipePtr->pidPtr[i])); Tcl_AppendElement(interp, buf); Tcl_DetachPids(1, &(pipePtr->pidPtr[i])); } if (pipePtr->numPids > 0) { ckfree((char *) pipePtr->pidPtr); pipePtr->numPids = 0; } }  /* *---------------------------------------------------------------------- * * PipeBlockModeProc -- * * Helper function to set blocking and nonblocking modes on a pipe based * channel. Invoked by generic IO level code. * * Results: * 0 if successful, errno when failed. * * Side effects: * Sets the device into blocking or non-blocking mode. * *---------------------------------------------------------------------- */ /* ARGSUSED */ static int PipeBlockModeProc( ClientData instanceData, /* Pipe state. */ int mode) /* The mode to set. Can be one of * TCL_MODE_BLOCKING or * TCL_MODE_NONBLOCKING. */ { PipeState *psPtr = (PipeState *) instanceData; int curStatus; int fd; #ifndef USE_FIONBIO if (psPtr->inFile) { fd = GetFd(psPtr->inFile); curStatus = fcntl(fd, F_GETFL); if (mode == TCL_MODE_BLOCKING) { curStatus &= (~(O_NONBLOCK)); } else { curStatus |= O_NONBLOCK; } if (fcntl(fd, F_SETFL, curStatus) < 0) { return errno; } } if (psPtr->outFile) { fd = GetFd(psPtr->outFile); curStatus = fcntl(fd, F_GETFL); if (mode == TCL_MODE_BLOCKING) { curStatus &= (~(O_NONBLOCK)); } else { curStatus |= O_NONBLOCK; } if (fcntl(fd, F_SETFL, curStatus) < 0) { return errno; } } #endif /* !FIONBIO */ #ifdef USE_FIONBIO if (psPtr->inFile) { fd = GetFd(psPtr->inFile); if (mode == TCL_MODE_BLOCKING) { curStatus = 0; } else { curStatus = 1; } if (ioctl(fd, (int) FIONBIO, &curStatus) < 0) { return errno; } } if (psPtr->outFile != NULL) { fd = GetFd(psPtr->outFile); if (mode == TCL_MODE_BLOCKING) { curStatus = 0; } else { curStatus = 1; } if (ioctl(fd, (int) FIONBIO, &curStatus) < 0) { return errno; } } #endif /* USE_FIONBIO */ psPtr->isNonBlocking = (mode == TCL_MODE_NONBLOCKING); return 0; }  /* *---------------------------------------------------------------------- * * PipeCloseProc -- * * This function is invoked by the generic IO level to perform * channel-type-specific cleanup when a command pipeline channel is * closed. * * Results: * 0 on success, errno otherwise. * * Side effects: * Closes the command pipeline channel. * *---------------------------------------------------------------------- */ /* ARGSUSED */ static int PipeCloseProc( ClientData instanceData, /* The pipe to close. */ Tcl_Interp *interp) /* For error reporting. */ { PipeState *pipePtr; Tcl_Channel errChan; int errorCode, result; errorCode = 0; result = 0; pipePtr = (PipeState *) instanceData; if (pipePtr->inFile) { if (TclpCloseFile(pipePtr->inFile) < 0) { errorCode = errno; } } if (pipePtr->outFile) { if ((TclpCloseFile(pipePtr->outFile) < 0) && (errorCode == 0)) { errorCode = errno; } } if (pipePtr->isNonBlocking || TclInExit()) { /* * If the channel is non-blocking or Tcl is being cleaned up, just * detach the children PIDs, reap them (important if we are in a * dynamic load module), and discard the errorFile. */ Tcl_DetachPids(pipePtr->numPids, pipePtr->pidPtr); Tcl_ReapDetachedProcs(); if (pipePtr->errorFile) { TclpCloseFile(pipePtr->errorFile); } } else { /* * Wrap the error file into a channel and give it to the cleanup * routine. */ if (pipePtr->errorFile) { errChan = Tcl_MakeFileChannel( (ClientData) INT2PTR(GetFd(pipePtr->errorFile)), TCL_READABLE); } else { errChan = NULL; } result = TclCleanupChildren(interp, pipePtr->numPids, pipePtr->pidPtr, errChan); } if (pipePtr->numPids != 0) { ckfree((char *) pipePtr->pidPtr); } ckfree((char *) pipePtr); if (errorCode == 0) { return result; } return errorCode; }  /* *---------------------------------------------------------------------- * * PipeInputProc -- * * This function is invoked from the generic IO level to read input from * a command pipeline based channel. * * Results: * The number of bytes read is returned or -1 on error. An output * argument contains a POSIX error code if an error occurs, or zero. * * Side effects: * Reads input from the input device of the channel. * *---------------------------------------------------------------------- */ static int PipeInputProc( ClientData instanceData, /* Pipe state. */ char *buf, /* Where to store data read. */ int toRead, /* How much space is available in the * buffer? */ int *errorCodePtr) /* Where to store error code. */ { PipeState *psPtr = (PipeState *) instanceData; int bytesRead; /* How many bytes were actually read from the * input device? */ *errorCodePtr = 0; /* * Assume there is always enough input available. This will block * appropriately, and read will unblock as soon as a short read is * possible, if the channel is in blocking mode. If the channel is * nonblocking, the read will never block. Some OSes can throw an * interrupt error, for which we should immediately retry. [Bug #415131] */ do { bytesRead = read(GetFd(psPtr->inFile), buf, (size_t) toRead); } while ((bytesRead < 0) && (errno == EINTR)); if (bytesRead < 0) { *errorCodePtr = errno; return -1; } else { return bytesRead; } }  /* *---------------------------------------------------------------------- * * PipeOutputProc-- * * This function is invoked from the generic IO level to write output to * a command pipeline based channel. * * Results: * The number of bytes written is returned or -1 on error. An output * argument contains a POSIX error code if an error occurred, or zero. * * Side effects: * Writes output on the output device of the channel. * *---------------------------------------------------------------------- */ static int PipeOutputProc( ClientData instanceData, /* Pipe state. */ const char *buf, /* The data buffer. */ int toWrite, /* How many bytes to write? */ int *errorCodePtr) /* Where to store error code. */ { PipeState *psPtr = (PipeState *) instanceData; int written; *errorCodePtr = 0; /* * Some OSes can throw an interrupt error, for which we should immediately * retry. [Bug #415131] */ do { written = write(GetFd(psPtr->outFile), buf, (size_t) toWrite); } while ((written < 0) && (errno == EINTR)); if (written < 0) { *errorCodePtr = errno; return -1; } else { return written; } }  /* *---------------------------------------------------------------------- * * PipeWatchProc -- * * Initialize the notifier to watch the fds from this channel. * * Results: * None. * * Side effects: * Sets up the notifier so that a future event on the channel will be * seen by Tcl. * *---------------------------------------------------------------------- */ static void PipeWatchProc( ClientData instanceData, /* The pipe state. */ int mask) /* Events of interest; an OR-ed combination of * TCL_READABLE, TCL_WRITABLE and * TCL_EXCEPTION. */ { PipeState *psPtr = (PipeState *) instanceData; int newmask; if (psPtr->inFile) { newmask = mask & (TCL_READABLE | TCL_EXCEPTION); if (newmask) { Tcl_CreateFileHandler(GetFd(psPtr->inFile), mask, (Tcl_FileProc *) Tcl_NotifyChannel, (ClientData) psPtr->channel); } else { Tcl_DeleteFileHandler(GetFd(psPtr->inFile)); } } if (psPtr->outFile) { newmask = mask & (TCL_WRITABLE | TCL_EXCEPTION); if (newmask) { Tcl_CreateFileHandler(GetFd(psPtr->outFile), mask, (Tcl_FileProc *) Tcl_NotifyChannel, (ClientData) psPtr->channel); } else { Tcl_DeleteFileHandler(GetFd(psPtr->outFile)); } } }  /* *---------------------------------------------------------------------- * * PipeGetHandleProc -- * * Called from Tcl_GetChannelHandle to retrieve OS handles from inside a * command pipeline based channel. * * Results: * Returns TCL_OK with the fd in handlePtr, or TCL_ERROR if there is no * handle for the specified direction. * * Side effects: * None. * *---------------------------------------------------------------------- */ static int PipeGetHandleProc( ClientData instanceData, /* The pipe state. */ int direction, /* TCL_READABLE or TCL_WRITABLE */ ClientData *handlePtr) /* Where to store the handle. */ { PipeState *psPtr = (PipeState *) instanceData; if (direction == TCL_READABLE && psPtr->inFile) { *handlePtr = (ClientData) INT2PTR(GetFd(psPtr->inFile)); return TCL_OK; } if (direction == TCL_WRITABLE && psPtr->outFile) { *handlePtr = (ClientData) INT2PTR(GetFd(psPtr->outFile)); return TCL_OK; } return TCL_ERROR; }  /* *---------------------------------------------------------------------- * * Tcl_WaitPid -- * * Implements the waitpid system call on Unix systems. * * Results: * Result of calling waitpid. * * Side effects: * Waits for a process to terminate. * *---------------------------------------------------------------------- */ Tcl_Pid Tcl_WaitPid( Tcl_Pid pid, int *statPtr, int options) { int result; pid_t real_pid; real_pid = (pid_t) PTR2INT(pid); while (1) { result = (int) waitpid(real_pid, statPtr, options); if ((result != -1) || (errno != EINTR)) { return (Tcl_Pid) INT2PTR(result); } } }  /* *---------------------------------------------------------------------- * * Tcl_PidObjCmd -- * * This function is invoked to process the "pid" Tcl command. See the * user documentation for details on what it does. * * Results: * A standard Tcl result. * * Side effects: * See the user documentation. * *---------------------------------------------------------------------- */ /* ARGSUSED */ int Tcl_PidObjCmd( ClientData dummy, /* Not used. */ Tcl_Interp *interp, /* Current interpreter. */ int objc, /* Number of arguments. */ Tcl_Obj *const *objv) /* Argument strings. */ { if (objc > 2) { Tcl_WrongNumArgs(interp, 1, objv, "?channelId?"); return TCL_ERROR; } if (objc == 1) { Tcl_SetObjResult(interp, Tcl_NewLongObj((long) getpid())); } else { Tcl_Channel chan; const Tcl_ChannelType *chanTypePtr; PipeState *pipePtr; int i; Tcl_Obj *resultPtr, *longObjPtr; chan = Tcl_GetChannel(interp, Tcl_GetString(objv[1]), NULL); if (chan == (Tcl_Channel) NULL) { return TCL_ERROR; } chanTypePtr = Tcl_GetChannelType(chan); if (chanTypePtr != &pipeChannelType) { return TCL_OK; } pipePtr = (PipeState *) Tcl_GetChannelInstanceData(chan); resultPtr = Tcl_NewObj(); for (i = 0; i < pipePtr->numPids; i++) { longObjPtr = Tcl_NewLongObj((long) TclpGetPid(pipePtr->pidPtr[i])); Tcl_ListObjAppendElement(NULL, resultPtr, longObjPtr); } Tcl_SetObjResult(interp, resultPtr); } return TCL_OK; }  /* *---------------------------------------------------------------------- * * TclpFinalizePipes -- * * Cleans up the pipe subsystem from Tcl_FinalizeThread * * Results: * None. * * Notes: * This function carries out no operation on Unix. * *---------------------------------------------------------------------- */ void TclpFinalizePipes(void) { }  /* * Local Variables: * mode: c * c-basic-offset: 4 * fill-column: 78 * End: */

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