projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 8168e750 WJ |
1 | /* |
| 2 | * Copyright (c) 1988 The Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * This code is derived from software written by Ken Arnold and | |
| 6 | * published in UNIX Review, Vol. 6, No. 8. | |
| 7 | * | |
| 8 | * Redistribution and use in source and binary forms, with or without | |
| 9 | * modification, are permitted provided that the following conditions | |
| 10 | * are met: | |
| 11 | * 1. Redistributions of source code must retain the above copyright | |
| 12 | * notice, this list of conditions and the following disclaimer. | |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright | |
| 14 | * notice, this list of conditions and the following disclaimer in the | |
| 15 | * documentation and/or other materials provided with the distribution. | |
| 16 | * 3. All advertising materials mentioning features or use of this software | |
| 17 | * must display the following acknowledgement: | |
| 18 | * This product includes software developed by the University of | |
| 19 | * California, Berkeley and its contributors. | |
| 20 | * 4. Neither the name of the University nor the names of its contributors | |
| 21 | * may be used to endorse or promote products derived from this software | |
| 22 | * without specific prior written permission. | |
| 23 | * | |
| 24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
| 25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
| 28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 34 | * SUCH DAMAGE. | |
| 35 | */ | |
| 36 | ||
| 37 | #if defined(LIBC_SCCS) && !defined(lint) | |
| 38 | static char sccsid[] = "@(#)popen.c 5.15 (Berkeley) 2/23/91"; | |
| 39 | #endif /* LIBC_SCCS and not lint */ | |
| 40 | ||
| 41 | #include <sys/param.h> | |
| 42 | #include <sys/signal.h> | |
| 43 | #include <sys/wait.h> | |
| 44 | #include <errno.h> | |
| 45 | #include <stdio.h> | |
| 46 | #include <stdlib.h> | |
| 47 | #include <string.h> | |
| 48 | #include <unistd.h> | |
| 49 | #include <paths.h> | |
| 50 | ||
| 51 | static pid_t *pids; | |
| 52 | ||
| 53 | FILE * | |
| 54 | popen(program, type) | |
| 55 | const char *program; | |
| 56 | const char *type; | |
| 57 | { | |
| 58 | FILE *iop; | |
| 59 | int pdes[2], fds, pid; | |
| 60 | ||
| 61 | if (*type != 'r' && *type != 'w' || type[1]) | |
| 62 | return (NULL); | |
| 63 | ||
| 64 | if (pids == NULL) { | |
| 65 | if ((fds = getdtablesize()) <= 0) | |
| 66 | return (NULL); | |
| 67 | if ((pids = (pid_t *)malloc((u_int)(fds * sizeof(int)))) == NULL) | |
| 68 | return (NULL); | |
| 69 | bzero((char *)pids, fds * sizeof(pid_t)); | |
| 70 | } | |
| 71 | if (pipe(pdes) < 0) | |
| 72 | return (NULL); | |
| 73 | switch (pid = vfork()) { | |
| 74 | case -1: /* error */ | |
| 75 | (void) close(pdes[0]); | |
| 76 | (void) close(pdes[1]); | |
| 77 | return (NULL); | |
| 78 | /* NOTREACHED */ | |
| 79 | case 0: /* child */ | |
| 80 | if (*type == 'r') { | |
| 81 | if (pdes[1] != STDOUT_FILENO) { | |
| 82 | (void) dup2(pdes[1], STDOUT_FILENO); | |
| 83 | (void) close(pdes[1]); | |
| 84 | } | |
| 85 | (void) close(pdes[0]); | |
| 86 | } else { | |
| 87 | if (pdes[0] != STDIN_FILENO) { | |
| 88 | (void) dup2(pdes[0], STDIN_FILENO); | |
| 89 | (void) close(pdes[0]); | |
| 90 | } | |
| 91 | (void) close(pdes[1]); | |
| 92 | } | |
| 93 | execl(_PATH_BSHELL, "sh", "-c", program, NULL); | |
| 94 | _exit(127); | |
| 95 | /* NOTREACHED */ | |
| 96 | } | |
| 97 | /* parent; assume fdopen can't fail... */ | |
| 98 | if (*type == 'r') { | |
| 99 | iop = fdopen(pdes[0], type); | |
| 100 | (void) close(pdes[1]); | |
| 101 | } else { | |
| 102 | iop = fdopen(pdes[1], type); | |
| 103 | (void) close(pdes[0]); | |
| 104 | } | |
| 105 | pids[fileno(iop)] = pid; | |
| 106 | return (iop); | |
| 107 | } | |
| 108 | ||
| 109 | int | |
| 110 | pclose(iop) | |
| 111 | FILE *iop; | |
| 112 | { | |
| 113 | register int fdes; | |
| 114 | int omask; | |
| 115 | union wait pstat; | |
| 116 | pid_t pid; | |
| 117 | ||
| 118 | /* | |
| 119 | * pclose returns -1 if stream is not associated with a | |
| 120 | * `popened' command, if already `pclosed', or waitpid | |
| 121 | * returns an error. | |
| 122 | */ | |
| 123 | if (pids == NULL || pids[fdes = fileno(iop)] == 0) | |
| 124 | return (-1); | |
| 125 | (void) fclose(iop); | |
| 126 | omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP)); | |
| 127 | do { | |
| 128 | pid = waitpid(pids[fdes], (int *) &pstat, 0); | |
| 129 | } while (pid == -1 && errno == EINTR); | |
| 130 | (void) sigsetmask(omask); | |
| 131 | pids[fdes] = 0; | |
| 132 | return (pid == -1 ? -1 : pstat.w_status); | |
| 133 | } |