/* * (c) 2008 Steve Bennett * * Implements the exec command for Jim * * Based on code originally from Tcl 6.7: * * Copyright 1987-1991 Regents of the University of California * Permission to use, copy, modify, and distribute this * software and its documentation for any purpose and without * fee is hereby granted, provided that the above copyright * notice appear in all copies. The University of California * makes no representations about the suitability of this * software for any purpose. It is provided "as is" without * express or implied warranty. */ #include #include #include #include #include #include #include "jim.h" #include "jim-subcmd.h" /* These two could be moved into the Tcl core */ static void Jim_SetResultErrno(Jim_Interp *interp, const char *msg) { Jim_SetResultString(interp, "", 0); Jim_AppendStrings(interp, Jim_GetResult(interp), msg, ": ", strerror(errno), NULL); } static void Jim_RemoveTrailingNewline(Jim_Obj *objPtr) { int len; const char *s = Jim_GetString(objPtr, &len); if (len > 0 && s[len-1] == '\n') { objPtr->length--; objPtr->bytes[objPtr->length] = '\0'; } } /** * Read from 'fd' and append the data to strObj * Returns JIM_OK if OK, or JIM_ERR on error. */ static int Jim_AppendStreamToString(Jim_Interp *interp, int fd, Jim_Obj *strObj) { while (1) { char buffer[256]; int count; count = read(fd, buffer, sizeof(buffer)); if (count == 0) { Jim_RemoveTrailingNewline(strObj); return JIM_OK; } if (count < 0) { return JIM_ERR; } Jim_AppendString(interp, strObj, buffer, count); } } #ifndef NO_FORK static int Jim_CreatePipeline(Jim_Interp *interp, int argc, Jim_Obj *const *argv, int **pidArrayPtr, int *inPipePtr, int *outPipePtr, int *errFilePtr); static void JimDetachPids(Jim_Interp *interp, int numPids, int *pidPtr); static int Jim_CleanupChildren(Jim_Interp *interp, int numPids, int *pidPtr, int errorId); static int Jim_ExecCmd(Jim_Interp *interp, int argc, Jim_Obj *const *argv) { int outputId; /* File id for output pipe. -1 * means command overrode. */ int errorId; /* File id for temporary file * containing error output. */ int *pidPtr; int numPids, result; /* * See if the command is to be run in background; if so, create * the command, detach it, and return. */ if (argc > 1 && Jim_CompareStringImmediate(interp, argv[argc - 1], "&")) { Jim_Obj *listObj; int i; argc--; numPids = Jim_CreatePipeline(interp, argc-1, argv+1, &pidPtr, NULL, NULL, NULL); if (numPids < 0) { return JIM_ERR; } /* The return value is a list of the pids */ listObj = Jim_NewListObj(interp, NULL, 0); for (i = 0; i < numPids; i++) { Jim_ListAppendElement(interp, listObj, Jim_NewIntObj(interp, pidPtr[i])); } Jim_SetResult(interp, listObj); JimDetachPids(interp, numPids, pidPtr); Jim_Free(pidPtr); return JIM_OK; } /* * Create the command's pipeline. */ numPids = Jim_CreatePipeline(interp, argc-1, argv+1, &pidPtr, (int *) NULL, &outputId, &errorId); if (numPids < 0) { return JIM_ERR; } /* * Read the child's output (if any) and put it into the result. */ Jim_SetResultString(interp, "", 0); result = JIM_OK; if (outputId != -1) { result = Jim_AppendStreamToString(interp, outputId, Jim_GetResult(interp)); if (result < 0) { Jim_SetResultErrno(interp, "error reading from output pipe"); } close(outputId); } if (Jim_CleanupChildren(interp, numPids, pidPtr, errorId) != JIM_OK) { result = JIM_ERR; } return result; } /* * Data structures of the following type are used by JimFork and * JimWaitPids to keep track of child processes. */ typedef struct { int pid; /* Process id of child. */ int status; /* Status returned when child exited or suspended. */ int flags; /* Various flag bits; see below for definitions. */ } WaitInfo; /* * Flag bits in WaitInfo structures: * * WI_READY - Non-zero means process has exited or * suspended since it was forked or last * returned by JimWaitPids. * WI_DETACHED - Non-zero means no-one cares about the * process anymore. Ignore it until it * exits, then forget about it. */ #define WI_READY 1 #define WI_DETACHED 2 /* REVISIT: Should be per-interpreter */ static WaitInfo *waitTable = NULL; static int waitTableSize = 0; /* Total number of entries available in waitTable. */ static int waitTableUsed = 0; /* Number of entries in waitTable that * are actually in use right now. Active * entries are always at the beginning * of the table. */ #define WAIT_TABLE_GROW_BY 4 /* *---------------------------------------------------------------------- * * JimFork -- * * Create a new process using the vfork system call, and keep * track of it for "safe" waiting with JimWaitPids. * * Results: * The return value is the value returned by the vfork system * call (0 means child, > 0 means parent (value is child id), * < 0 means error). * * Side effects: * A new process is created, and an entry is added to an internal * table of child processes if the process is created successfully. * *---------------------------------------------------------------------- */ static int JimFork(void) { WaitInfo *waitPtr; pid_t pid; /* * Disable SIGPIPE signals: if they were allowed, this process * might go away unexpectedly if children misbehave. This code * can potentially interfere with other application code that * expects to handle SIGPIPEs; what's really needed is an * arbiter for signals to allow them to be "shared". */ if (waitTable == NULL) { (void) signal(SIGPIPE, SIG_IGN); } /* * Enlarge the wait table if there isn't enough space for a new * entry. */ if (waitTableUsed == waitTableSize) { waitTableSize += WAIT_TABLE_GROW_BY; waitTable = (WaitInfo *)realloc(waitTable, waitTableSize * sizeof(WaitInfo)); } /* * Make a new process and enter it into the table if the fork * is successful. */ waitPtr = &waitTable[waitTableUsed]; pid = fork(); if (pid > 0) { waitPtr->pid = pid; waitPtr->flags = 0; waitTableUsed++; } return pid; } /* *---------------------------------------------------------------------- * * JimWaitPids -- * * This procedure is used to wait for one or more processes created * by JimFork to exit or suspend. It records information about * all processes that exit or suspend, even those not waited for, * so that later waits for them will be able to get the status * information. * * Results: * -1 is returned if there is an error in the wait kernel call. * Otherwise the pid of an exited/suspended process from *pidPtr * is returned and *statusPtr is set to the status value returned * by the wait kernel call. * * Side effects: * Doesn't return until one of the pids at *pidPtr exits or suspends. * *---------------------------------------------------------------------- */ static int JimWaitPids(int numPids, int *pidPtr, int *statusPtr) { int i, count, pid; WaitInfo *waitPtr; int anyProcesses; int status; while (1) { /* * Scan the table of child processes to see if one of the * specified children has already exited or suspended. If so, * remove it from the table and return its status. */ anyProcesses = 0; for (waitPtr = waitTable, count = waitTableUsed; count > 0; waitPtr++, count--) { for (i = 0; i < numPids; i++) { if (pidPtr[i] != waitPtr->pid) { continue; } anyProcesses = 1; if (waitPtr->flags & WI_READY) { *statusPtr = *((int *) &waitPtr->status); pid = waitPtr->pid; if (WIFEXITED(waitPtr->status) || WIFSIGNALED(waitPtr->status)) { if (waitPtr != &waitTable[waitTableUsed-1]) { *waitPtr = waitTable[waitTableUsed-1]; } waitTableUsed--; } else { waitPtr->flags &= ~WI_READY; } return pid; } } } /* * Make sure that the caller at least specified one valid * process to wait for. */ if (!anyProcesses) { errno = ECHILD; return -1; } /* * Wait for a process to exit or suspend, then update its * entry in the table and go back to the beginning of the * loop to see if it's one of the desired processes. */ pid = wait(&status); if (pid < 0) { return pid; } for (waitPtr = waitTable, count = waitTableUsed; ; waitPtr++, count--) { if (count == 0) { break; /* Ignore unknown processes. */ } if (pid != waitPtr->pid) { continue; } /* * If the process has been detached, then ignore anything * other than an exit, and drop the entry on exit. */ if (waitPtr->flags & WI_DETACHED) { if (WIFEXITED(status) || WIFSIGNALED(status)) { *waitPtr = waitTable[waitTableUsed-1]; waitTableUsed--; } } else { waitPtr->status = status; waitPtr->flags |= WI_READY; } break; } } } /* *---------------------------------------------------------------------- * * JimDetachPids -- * * This procedure is called to indicate that one or more child * processes have been placed in background and are no longer * cared about. They should be ignored in future calls to * JimWaitPids. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ static void JimDetachPids(Jim_Interp *interp, int numPids, int *pidPtr) { WaitInfo *waitPtr; int i, count, pid; for (i = 0; i < numPids; i++) { pid = pidPtr[i]; for (waitPtr = waitTable, count = waitTableUsed; count > 0; waitPtr++, count--) { if (pid != waitPtr->pid) { continue; } /* * If the process has already exited then destroy its * table entry now. */ if ((waitPtr->flags & WI_READY) && (WIFEXITED(waitPtr->status) || WIFSIGNALED(waitPtr->status))) { *waitPtr = waitTable[waitTableUsed-1]; waitTableUsed--; } else { waitPtr->flags |= WI_DETACHED; } goto nextPid; } Jim_Panic(interp, "Jim_Detach couldn't find process"); nextPid: continue; } } /* *---------------------------------------------------------------------- * * Jim_CreatePipeline -- * * Given an argc/argv array, instantiate a pipeline of processes * as described by the argv. * * 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. * *---------------------------------------------------------------------- */ static int Jim_CreatePipeline(Jim_Interp *interp, int argc, Jim_Obj *const *argv, int **pidArrayPtr, int *inPipePtr, int *outPipePtr, int *errFilePtr) { int *pidPtr = NULL; /* Points to malloc-ed array holding all * the pids of child processes. */ int numPids = 0; /* Actual number of processes that exist * at *pidPtr right now. */ int cmdCount; /* Count of number of distinct commands * found in argc/argv. */ const char *input = NULL; /* Describes input for pipeline, depending * on "inputFile". NULL means take input * from stdin/pipe. */ #define FILE_NAME 0 /* input/output: filename */ #define FILE_APPEND 1 /* output only: filename, append */ #define FILE_HANDLE 2 /* input/output: filehandle */ #define FILE_TEXT 3 /* input only: input is actual text */ int inputFile = FILE_NAME; /* 1 means input is name of input file. * 2 means input is filehandle name. * 0 means input holds actual * text to be input to command. */ int outputFile = FILE_NAME; /* 0 means output is the name of output file. * 1 means output is the name of output file, and append. * 2 means output is filehandle name. * All this is ignored if output is NULL */ int errorFile = FILE_NAME; /* 0 means error is the name of error file. * 1 means error is the name of error file, and append. * 2 means error is filehandle name. * All this is ignored if error is NULL */ const char *output = NULL; /* Holds name of output file to pipe to, * or NULL if output goes to stdout/pipe. */ const char *error = NULL; /* Holds name of stderr file to pipe to, * or NULL if stderr goes to stderr/pipe. */ int inputId = -1; /* Readable file id input to current command in * pipeline (could be file or pipe). -1 * means use stdin. */ int outputId = -1; /* Writable file id for output from current * command in pipeline (could be file or pipe). * -1 means use stdout. */ int errorId = -1; /* Writable file id for all standard error * output from all commands in pipeline. -1 * means use stderr. */ int lastOutputId = -1; /* Write file id for output from last command * in pipeline (could be file or pipe). * -1 means use stdout. */ int pipeIds[2]; /* File ids for pipe that's being created. */ int firstArg, lastArg; /* Indexes of first and last arguments in * current command. */ int lastBar; char *execName; int i, pid; /* Holds the args which will be used to exec */ char **arg_array = Jim_Alloc(sizeof(*arg_array) * (argc + 1)); int arg_count = 0; if (inPipePtr != NULL) { *inPipePtr = -1; } if (outPipePtr != NULL) { *outPipePtr = -1; } if (errFilePtr != NULL) { *errFilePtr = -1; } pipeIds[0] = pipeIds[1] = -1; /* * First, scan through all the arguments to figure out the structure * of the pipeline. Count the number of distinct processes (it's the * number of "|" arguments). If there are "<", "<<", or ">" arguments * then make note of input and output redirection and remove these * arguments and the arguments that follow them. */ cmdCount = 1; lastBar = -1; for (i = 0; i < argc; i++) { const char *arg = Jim_GetString(argv[i], NULL); if (arg[0] == '<') { inputFile = FILE_NAME; input = arg + 1; if (*input == '<') { inputFile = FILE_TEXT; input++; } else if (*input == '@') { inputFile = FILE_HANDLE; input++; } if (!*input && ++i < argc) { input = Jim_GetString(argv[i], NULL); } } else if (arg[0] == '>') { int dup_error = 0; outputFile = FILE_NAME; output = arg + 1; if (*output == '>') { outputFile = FILE_APPEND; output++; } if (*output == '&') { /* Redirect stderr too */ output++; dup_error = 1; } if (*output == '@') { outputFile = FILE_HANDLE; output++; } if (!*output && ++i < argc) { output = Jim_GetString(argv[i], NULL); } if (dup_error) { errorFile = outputFile; error = output; } } else if (arg[0] == '2' && arg[1] == '>') { error = arg + 2; errorFile = FILE_NAME; if (*error == '@') { errorFile = FILE_HANDLE; error++; } else if (*error == '>') { errorFile = FILE_APPEND; error++; } if (!*error && ++i < argc) { error = Jim_GetString(argv[i], NULL); } } else { if (strcmp(arg, "|") == 0 || strcmp(arg, "|&") == 0) { if (i == lastBar + 1 || i == argc - 1) { Jim_SetResultString(interp, "illegal use of | or |& in command", -1); Jim_Free(arg_array); return -1; } lastBar = i; cmdCount++; } /* Either |, |& or a "normal" arg, so store it in the arg array */ arg_array[arg_count++] = (char *)arg; continue; } if (i >= argc) { Jim_SetResultString(interp, "", 0); Jim_AppendStrings(interp, Jim_GetResult(interp), "can't specify \"", arg, "\" as last word in command", NULL); Jim_Free(arg_array); return -1; } } if (arg_count == 0) { Jim_SetResultString(interp, "didn't specify command to execute", -1); Jim_Free(arg_array); return -1; } /* * Set up the redirected input source for the pipeline, if * so requested. */ if (input != NULL) { if (inputFile == FILE_TEXT) { /* * Immediate data in command. Create temporary file and * put data into file. */ #define TMP_STDIN_NAME "/tmp/tcl.in.XXXXXX" char inName[sizeof(TMP_STDIN_NAME) + 1]; int length; strcpy(inName, TMP_STDIN_NAME); inputId = mkstemp(inName); if (inputId < 0) { Jim_SetResultErrno(interp, "couldn't create input file for command"); goto error; } length = strlen(input); if (write(inputId, input, length) != length) { Jim_SetResultErrno(interp, "couldn't write file input for command"); goto error; } if (lseek(inputId, 0L, SEEK_SET) == -1 || unlink(inName) == -1) { Jim_SetResultErrno(interp, "couldn't reset or remove input file for command"); goto error; } } else if (inputFile == FILE_HANDLE) { /* Should be a file descriptor */ Jim_Obj *fhObj = Jim_NewStringObj(interp, input, -1); FILE *fh = Jim_AioFilehandle(interp, fhObj); Jim_FreeNewObj(interp, fhObj); if (fh == NULL) { goto error; } inputId = dup(fileno(fh)); } else { /* * File redirection. Just open the file. */ inputId = open(input, O_RDONLY, 0); if (inputId < 0) { Jim_SetResultString(interp, "", 0); Jim_AppendStrings(interp, Jim_GetResult(interp), "couldn't read file \"", input, "\": ", strerror(errno), NULL); goto error; } } } else if (inPipePtr != NULL) { if (pipe(pipeIds) != 0) { Jim_SetResultErrno(interp, "couldn't create input pipe for command"); goto error; } inputId = pipeIds[0]; *inPipePtr = pipeIds[1]; pipeIds[0] = pipeIds[1] = -1; } /* * Set up the redirected output sink for the pipeline from one * of two places, if requested. */ if (output != NULL) { if (outputFile == FILE_HANDLE) { Jim_Obj *fhObj = Jim_NewStringObj(interp, output, -1); FILE *fh = Jim_AioFilehandle(interp, fhObj); Jim_FreeNewObj(interp, fhObj); if (fh == NULL) { goto error; } fflush(fh); lastOutputId = dup(fileno(fh)); } else { /* * Output is to go to a file. */ int mode = O_WRONLY|O_CREAT|O_TRUNC; if (outputFile == FILE_APPEND) { mode = O_WRONLY|O_CREAT|O_APPEND; } lastOutputId = open(output, mode, 0666); if (lastOutputId < 0) { Jim_SetResultString(interp, "", 0); Jim_AppendStrings(interp, Jim_GetResult(interp), "couldn't write file \"", output, "\": ", strerror(errno), NULL); goto error; } } } else if (outPipePtr != NULL) { /* * Output is to go to a pipe. */ if (pipe(pipeIds) != 0) { Jim_SetResultErrno(interp, "couldn't create output pipe"); goto error; } lastOutputId = pipeIds[1]; *outPipePtr = pipeIds[0]; pipeIds[0] = pipeIds[1] = -1; } /* If we are redirecting stderr with 2>filename or 2>@fileId, then we ignore errFilePtr */ if (error != NULL) { if (errorFile == FILE_HANDLE) { Jim_Obj *fhObj = Jim_NewStringObj(interp, error, -1); FILE *fh = Jim_AioFilehandle(interp, fhObj); Jim_FreeNewObj(interp, fhObj); if (fh == NULL) { goto error; } fflush(fh); errorId = dup(fileno(fh)); } else { /* * Output is to go to a file. */ int mode = O_WRONLY|O_CREAT|O_TRUNC; if (errorFile == FILE_APPEND) { mode = O_WRONLY|O_CREAT|O_APPEND; } errorId = open(error, mode, 0666); if (errorId < 0) { Jim_SetResultString(interp, "", 0); Jim_AppendStrings(interp, Jim_GetResult(interp), "couldn't write file \"", error, "\": ", strerror(errno), NULL); } } } 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. */ #define TMP_STDERR_NAME "/tmp/tcl.err.XXXXXX" char errName[sizeof(TMP_STDERR_NAME) + 1]; strcpy(errName, TMP_STDERR_NAME); errorId = mkstemp(errName); if (errorId < 0) { errFileError: Jim_SetResultErrno(interp, "couldn't create error file for command"); goto error; } *errFilePtr = open(errName, O_RDONLY, 0); if (*errFilePtr < 0) { goto errFileError; } if (unlink(errName) == -1) { Jim_SetResultErrno(interp, "couldn't remove error file for command"); goto error; } } /* * Scan through the argc array, forking off a process for each * group of arguments between "|" arguments. */ pidPtr = (int *)Jim_Alloc(cmdCount * sizeof(*pidPtr)); for (i = 0; i < numPids; i++) { pidPtr[i] = -1; } for (firstArg = 0; firstArg < arg_count; numPids++, firstArg = lastArg+1) { int pipe_dup_err = 0; for (lastArg = firstArg; lastArg < arg_count; lastArg++) { if (arg_array[lastArg][0] == '|') { if (arg_array[lastArg][1] == '&') { pipe_dup_err = 1; } break; } } /* Replace | with NULL for execv() */ arg_array[lastArg] = NULL; if (lastArg == arg_count) { outputId = lastOutputId; } else { if (pipe(pipeIds) != 0) { Jim_SetResultErrno(interp, "couldn't create pipe"); goto error; } outputId = pipeIds[1]; } execName = arg_array[firstArg]; pid = JimFork(); if (pid == -1) { Jim_SetResultErrno(interp, "couldn't fork child process"); goto error; } if (pid == 0) { char errSpace[200]; int rc; if (pipe_dup_err) { errorId = outputId; } if ((inputId != -1 && dup2(inputId, 0) == -1) || (outputId != -1 && dup2(outputId, 1) == -1) || (errorId != -1 &&(dup2(errorId, 2) == -1))) { static const char err[] = "forked process couldn't set up input/output\n"; rc = write(errorId < 0 ? 2 : errorId, err, strlen(err)); _exit(1); } for (i = 3; (i <= outputId) || (i <= inputId) || (i <= errorId); i++) { close(i); } execvp(execName, &arg_array[firstArg]); sprintf(errSpace, "couldn't find \"%.150s\" to execute\n", arg_array[firstArg]); rc = write(2, errSpace, strlen(errSpace)); _exit(1); } else { pidPtr[numPids] = pid; } /* * Close off our copies of file descriptors that were set up for * this child, then set up the input for the next child. */ if (inputId != -1) { close(inputId); } if (outputId != -1) { close(outputId); } inputId = pipeIds[0]; pipeIds[0] = pipeIds[1] = -1; } *pidArrayPtr = pidPtr; /* * All done. Cleanup open files lying around and then return. */ cleanup: if (inputId != -1) { close(inputId); } if (lastOutputId != -1) { close(lastOutputId); } if (errorId != -1) { close(errorId); } Jim_Free(arg_array); 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 ((inPipePtr != NULL) && (*inPipePtr != -1)) { close(*inPipePtr); *inPipePtr = -1; } if ((outPipePtr != NULL) && (*outPipePtr != -1)) { close(*outPipePtr); *outPipePtr = -1; } if ((errFilePtr != NULL) && (*errFilePtr != -1)) { close(*errFilePtr); *errFilePtr = -1; } if (pipeIds[0] != -1) { close(pipeIds[0]); } if (pipeIds[1] != -1) { close(pipeIds[1]); } if (pidPtr != NULL) { for (i = 0; i < numPids; i++) { if (pidPtr[i] != -1) { JimDetachPids(interp, 1, &pidPtr[i]); } } Jim_Free(pidPtr); } numPids = -1; goto cleanup; } /* *---------------------------------------------------------------------- * * CleanupChildren -- * * 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, JIM_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. File errorId gets closed, and pidPtr is freed * back to the storage allocator. * *---------------------------------------------------------------------- */ static int Jim_CleanupChildren(Jim_Interp *interp, int numPids, int *pidPtr, int errorId) { int result = JIM_OK; int i, pid; int len; const char *p; for (i = 0; i < numPids; i++) { int waitStatus = 0; pid = JimWaitPids(1, &pidPtr[i], &waitStatus); if (pid == -1) { /* This can happen if the process was already reaped, so just ignore it */ 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)) { result = JIM_ERR; if (WIFEXITED(waitStatus)) { /* Nothing */ } else if (WIFSIGNALED(waitStatus)) { /* REVISIT: Name the signal */ Jim_SetResultString(interp, "child killed by signal", -1); } else if (WIFSTOPPED(waitStatus)) { Jim_SetResultString(interp, "child suspended", -1); } } } Jim_Free(pidPtr); /* * Read the standard error file. If there's anything there, * then add the file's contents to the result * string. */ if (errorId >= 0) { if (Jim_AppendStreamToString(interp, errorId, Jim_GetResult(interp)) != JIM_OK) { Jim_SetResultErrno(interp, "error reading from stderr output file"); result = JIM_ERR; } close(errorId); } /* * If the last character of interp->result is a newline, then remove * the newline character (the newline would just confuse things). * * Note: Ideally we could do this by just reducing the length of stringrep * by 1, but there is not API for this :-( */ p = Jim_GetString(Jim_GetResult(interp), &len); if (len > 0 && p[len - 1] == '\n') { Jim_SetResultString(interp, p, len - 1); } return result; } #else /* NO_FORK */ static int Jim_ExecCmd(Jim_Interp *interp, int argc, Jim_Obj *const *argv) { int pid; int tmpfd; int status; int result; char **nargv; int i; #define TMP_NAME "/tmp/tcl.exec.XXXXXX" char tmpname[sizeof(TMP_NAME) + 1]; /* Create a temporary file for the output from our exec command */ strcpy(tmpname, TMP_NAME); tmpfd = mkstemp(tmpname); if (tmpfd < 0) { Jim_SetResultErrno(interp, "couldn't create temp file file for exec"); return JIM_ERR; } nargv = Jim_Alloc(sizeof(*nargv) * argc); for (i = 1; i < argc; i++) { nargv[i - 1] = (char *)Jim_GetString(argv[i], NULL); } nargv[i - 1] = NULL; /*printf("Writing output to %s, fd=%d\n", tmpname, tmpfd);*/ unlink(tmpname); /* Use vfork and send output to this temporary file */ pid = vfork(); if (pid == 0) { close(0); open("/dev/null", O_RDONLY); close(1); dup(tmpfd); close(2); /*open("/dev/null", O_WRONLY);*/ dup(tmpfd); close(tmpfd); execvp(nargv[0], nargv); _exit(127); } Jim_Free(nargv); /* Wait for the child to exit */ do { waitpid(pid, &status, 0); } while (!WIFEXITED(status)); /* * Read the child's output (if any) and put it into the result. */ lseek(tmpfd, 0L, SEEK_SET); Jim_SetResultString(interp, "", 0); result = Jim_AppendStreamToString(interp, tmpfd, Jim_GetResult(interp)); if (result < 0) { Jim_SetResultErrno(interp, "error reading result"); } close(tmpfd); return result; } #endif int Jim_execInit(Jim_Interp *interp) { if (Jim_PackageProvide(interp, "exec", "1.0", JIM_ERRMSG) != JIM_OK) { return JIM_ERR; } Jim_CreateCommand(interp, "exec", Jim_ExecCmd, NULL, NULL); return JIM_OK; }