/* * Copyright (c) 1988, 1993 * The Regents of the University of California. All rights reserved. * Copyright (c) 2004 The DragonFly Project. All rights reserved. * * This code is derived from software written by Ken Arnold and * published in UNIX Review, Vol. 6, No. 8. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD: src/lib/libc/gen/popen.c,v 1.14 2000/01/27 23:06:19 jasone Exp $ * $Id: popen.c,v 1.6 2005/02/06 06:57:30 cpressey Exp $ * * @(#)popen.c 8.3 (Berkeley) 5/3/95 * * A modified version of the standard popen()/pclose() functions * which adds a third function, pgetpid(), which allows the program * which used popen() to obtain the pid of the process on the other * end of the pipe. */ #include <sys/param.h> #include <sys/wait.h> #include <sys/types.h> #include <sys/time.h> #include <errno.h> #include <signal.h> #include <stdarg.h> #include <paths.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include "popen.h" extern char **environ; static struct pid { struct pid *next; FILE *fp; pid_t pid; } *pidlist; FILE * aura_popen(const char *fmt, const char *type, ...) { FILE *iop; struct pid *cur; struct pid *p; va_list args; char *command; const char *argv[4]; int pdes[2], pid; volatile enum { READ, WRITE, TWO_WAY } pipedir; /* * Lite2 introduced two-way popen() pipes using socketpair(). * FreeBSD's pipe() is bidirectional, so we use that. */ if (strchr(type, '+')) { pipedir = TWO_WAY; } else { if (type[1] != '\0') return(NULL); if (*type == 'r') pipedir = READ; else if (*type == 'w') pipedir = WRITE; else return(NULL); } if (pipe(pdes) < 0) return(NULL); if ((cur = malloc(sizeof(struct pid))) == NULL) { close(pdes[0]); close(pdes[1]); return(NULL); } va_start(args, type); vasprintf(&command, fmt, args); va_end(args); argv[0] = "sh"; argv[1] = "-c"; argv[2] = command; argv[3] = NULL; switch (pid = vfork()) { case -1: /* Error. */ close(pdes[0]); close(pdes[1]); free(cur); free(command); return(NULL); /* NOTREACHED */ case 0: /* Child. */ if (pipedir == READ || pipedir == TWO_WAY) { /* * The dup2() to STDIN_FILENO is repeated to avoid * writing to pdes[1], which might corrupt the * parent's copy. This isn't good enough in * general, since the _exit() is no return, so * the compiler is free to corrupt all the local * variables. */ close(pdes[0]); if (pdes[1] != STDOUT_FILENO) { dup2(pdes[1], STDOUT_FILENO); close(pdes[1]); if (pipedir == TWO_WAY) dup2(STDOUT_FILENO, STDIN_FILENO); } else if (pipedir == TWO_WAY && (pdes[1] != STDIN_FILENO)) { dup2(pdes[1], STDIN_FILENO); } } else { if (pdes[0] != STDIN_FILENO) { dup2(pdes[0], STDIN_FILENO); close(pdes[0]); } close(pdes[1]); } for (p = pidlist; p; p = p->next) { close(fileno(p->fp)); } execve(_PATH_BSHELL, __DECONST(char **, argv), environ); _exit(127); /* NOTREACHED */ } /* Parent; assume fdopen can't fail. */ if (pipedir == READ || pipedir == TWO_WAY) { iop = fdopen(pdes[0], type); close(pdes[1]); } else { iop = fdopen(pdes[1], type); close(pdes[0]); } /* Link into list of file descriptors. */ cur->fp = iop; cur->pid = pid; cur->next = pidlist; pidlist = cur; free(command); return(iop); } /* * pclose -- * Pclose returns -1 if stream is not associated with a `popened' command, * if already `pclosed', or waitpid returns an error. */ int aura_pclose(FILE *iop) { struct pid *cur, *last; int pstat; pid_t pid; /* Find the appropriate file pointer. */ for (last = NULL, cur = pidlist; cur; last = cur, cur = cur->next) { if (cur->fp == iop) break; } if (cur == NULL) return (-1); fclose(iop); do { pid = wait4(cur->pid, &pstat, 0, (struct rusage *)0); } while (pid == -1 && errno == EINTR); /* Remove the entry from the linked list. */ if (last == NULL) pidlist = cur->next; else last->next = cur->next; free(cur); return (pid == -1 ? -1 : pstat); } pid_t aura_pgetpid(FILE *iop) { struct pid *cur; /* Find the appropriate file pointer. */ for (cur = pidlist; cur; cur = cur->next) if (cur->fp == iop) break; if (cur == NULL) return (-1); return(cur->pid); } /* * Returns: * 1 if all went well. * 0 if an error occurred, in which case err is set to: * AURA_PGETS_TIMEOUT: select() timed out. * AURA_PGETS_SELECT_ERR: a select() error occurred. * AURA_PGETS_EOF: end of file condition on pipe. * AURA_PGETS_FGETS_ERR: a fgets() error occurred. */ int aura_pgets(FILE *p, char *buf, size_t len, long msec, int *err) { struct timeval tv; struct timeval *tvp; fd_set r; int n; tv.tv_sec = msec / 1000; tv.tv_usec = (msec % 1000) * 1000; tvp = (msec < 0 ? NULL : &tv); FD_ZERO(&r); FD_SET(fileno(p), &r); *err = 0; buf[0] = '\0'; if (feof(p)) { *err = AURA_PGETS_EOF; return(0); } if (ferror(p)) { *err = AURA_PGETS_FGETS_ERR; return(0); } n = select(fileno(p) + 1, &r, NULL, NULL, tvp); if (n == 0) { *err = AURA_PGETS_TIMEOUT; return(0); } else if (n < 0) { *err = AURA_PGETS_SELECT_ERR; return(0); } else { /* Data came in; read it. */ if (fgets(buf, len, p) == NULL) { if (feof(p)) { *err = AURA_PGETS_EOF; } else { *err = AURA_PGETS_FGETS_ERR; } return(0); } else { return(1); } } }
