1/* 2 * Copyright (c) 1988, 1993 3 * The Regents of the University of California. 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 --- 21 unchanged lines hidden (view full) --- 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) |
38static char sccsid[] = "@(#)popen.c 8.3 (Berkeley) 5/3/95"; |
39#endif /* LIBC_SCCS and not lint */ 40 41#include <sys/param.h> 42#include <sys/wait.h> |
43#include <sys/socket.h> |
44 45#include <signal.h> 46#include <errno.h> 47#include <unistd.h> 48#include <stdio.h> 49#include <stdlib.h> 50#include <string.h> 51#include <paths.h> 52 53static struct pid { 54 struct pid *next; 55 FILE *fp; 56 pid_t pid; 57} *pidlist; 58 59FILE * |
60popen(command, type) 61 const char *command, *type; |
62{ 63 struct pid *cur; 64 FILE *iop; |
65 int pdes[2], pid, twoway; |
66 |
67 /* 68 * Lite2 introduced two-way popen() pipes using socketpair(). 69 * FreeBSD's pipe() is bidirectional, so we use that. 70 */ 71 if (strchr(type, '+')) { 72 twoway = 1; 73 type = "r+"; 74 } else { 75 twoway = 0; 76 if (*type != 'r' && *type != 'w' || type[1]) 77 return (NULL); 78 } 79 if (pipe(pdes) < 0) |
80 return (NULL); 81 82 if ((cur = malloc(sizeof(struct pid))) == NULL) 83 return (NULL); 84 |
85 switch (pid = vfork()) { 86 case -1: /* Error. */ 87 (void)close(pdes[0]); 88 (void)close(pdes[1]); 89 free(cur); 90 return (NULL); 91 /* NOTREACHED */ 92 case 0: /* Child. */ 93 if (*type == 'r') { 94 if (pdes[1] != STDOUT_FILENO) { 95 (void)dup2(pdes[1], STDOUT_FILENO); 96 (void)close(pdes[1]); |
97 pdes[1] = STDOUT_FILENO; |
98 } 99 (void) close(pdes[0]); |
100 if (twoway && (pdes[1] != STDIN_FILENO)) 101 (void)dup2(pdes[1], STDIN_FILENO); |
102 } else { 103 if (pdes[0] != STDIN_FILENO) { 104 (void)dup2(pdes[0], STDIN_FILENO); 105 (void)close(pdes[0]); 106 } 107 (void)close(pdes[1]); 108 } |
109 execl(_PATH_BSHELL, "sh", "-c", command, NULL); |
110 _exit(127); 111 /* NOTREACHED */ 112 } 113 114 /* Parent; assume fdopen can't fail. */ 115 if (*type == 'r') { 116 iop = fdopen(pdes[0], type); 117 (void)close(pdes[1]); --- 17 unchanged lines hidden (view full) --- 135 * if already `pclosed', or waitpid returns an error. 136 */ 137int 138pclose(iop) 139 FILE *iop; 140{ 141 register struct pid *cur, *last; 142 int omask; |
143 int pstat; |
144 pid_t pid; 145 |
146 /* Find the appropriate file pointer. */ 147 for (last = NULL, cur = pidlist; cur; last = cur, cur = cur->next) 148 if (cur->fp == iop) 149 break; 150 if (cur == NULL) 151 return (-1); 152 |
153 (void)fclose(iop); 154 |
155 do { |
156 pid = waitpid(cur->pid, &pstat, 0); |
157 } while (pid == -1 && errno == EINTR); |
158 159 /* Remove the entry from the linked list. */ 160 if (last == NULL) 161 pidlist = cur->next; 162 else 163 last->next = cur->next; 164 free(cur); 165 |
166 return (pid == -1 ? -1 : pstat); |
167} |