toolchain/gcc/newlib/libc/posix/popen.c

   1 /*      $NetBSD: popen.c,v 1.11 1995/06/16 07:05:33 jtc Exp $   */
   2
   3 /*
   4  * Copyright (c) 1988, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software written by Ken Arnold and
   8  * published in UNIX Review, Vol. 6, No. 8.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 #if defined(LIBC_SCCS) && !defined(lint)
  40 #if 0
  41 static char sccsid[] = "@(#)popen.c     8.1 (Berkeley) 6/4/93";
  42 #else
  43 static char rcsid[] = "$NetBSD: popen.c,v 1.11 1995/06/16 07:05:33 jtc Exp $";
  44 #endif
  45 #endif /* LIBC_SCCS and not lint */
  46
  47 #include <sys/param.h>
  48 #include <sys/types.h>
  49 #include <sys/wait.h>
  50
  51 #include <signal.h>
  52 #include <errno.h>
  53 #include <unistd.h>
  54 #include <stdio.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include <paths.h>
  58
  59 static struct pid {
  60         struct pid *next;
  61         FILE *fp;
  62         pid_t pid;
  63 } *pidlist;
  64
  65 FILE *
  66 _DEFUN(popen, (program, type),
  67         const char *program _AND
  68         const char *type)
  69 {
  70         struct pid *cur;
  71         FILE *iop;
  72         int pdes[2], pid;
  73
  74        if ((*type != 'r' && *type != 'w')
  75            || (type[1]
  76 #ifdef __CYGWIN__
  77                && (type[2] || (type[1] != 'b' && type[1] != 't'))
  78 #endif
  79                                )) {
  80                 errno = EINVAL;
  81                 return (NULL);
  82         }
  83
  84         if ((cur = malloc(sizeof(struct pid))) == NULL)
  85                 return (NULL);
  86
  87         if (pipe(pdes) < 0) {
  88                 free(cur);
  89                 return (NULL);
  90         }
  91
  92         switch (pid = vfork()) {
  93         case -1:                        /* Error. */
  94                 (void)close(pdes[0]);
  95                 (void)close(pdes[1]);
  96                 free(cur);
  97                 return (NULL);
  98                 /* NOTREACHED */
  99         case 0:                         /* Child. */
 100                 if (*type == 'r') {
 101                         if (pdes[1] != STDOUT_FILENO) {
 102                                 (void)dup2(pdes[1], STDOUT_FILENO);
 103                                 (void)close(pdes[1]);
 104                         }
 105                         (void) close(pdes[0]);
 106                 } else {
 107                         if (pdes[0] != STDIN_FILENO) {
 108                                 (void)dup2(pdes[0], STDIN_FILENO);
 109                                 (void)close(pdes[0]);
 110                         }
 111                         (void)close(pdes[1]);
 112                 }
 113                 execl(_PATH_BSHELL, "sh", "-c", program, NULL);
 114 #ifdef __CYGWIN__
 115                 /* On cygwin32, we may not have /bin/sh.  In that
 116                    case, try to find sh on PATH.  */
 117                 execlp("sh", "sh", "-c", program, NULL);
 118 #endif
 119                 _exit(127);
 120                 /* NOTREACHED */
 121         }
 122
 123         /* Parent; assume fdopen can't fail. */
 124         if (*type == 'r') {
 125                 iop = fdopen(pdes[0], type);
 126                 (void)close(pdes[1]);
 127         } else {
 128                 iop = fdopen(pdes[1], type);
 129                 (void)close(pdes[0]);
 130         }
 131
 132         /* Link into list of file descriptors. */
 133         cur->fp = iop;
 134         cur->pid =  pid;
 135         cur->next = pidlist;
 136         pidlist = cur;
 137
 138         return (iop);
 139 }
 140
 141 /*
 142  * pclose --
 143  *      Pclose returns -1 if stream is not associated with a `popened' command,
 144  *      if already `pclosed', or waitpid returns an error.
 145  */
 146 int
 147 _DEFUN(pclose, (iop),
 148         FILE *iop)
 149 {
 150         register struct pid *cur, *last;
 151         int pstat;
 152         pid_t pid;
 153
 154         (void)fclose(iop);
 155
 156         /* Find the appropriate file pointer. */
 157         for (last = NULL, cur = pidlist; cur; last = cur, cur = cur->next)
 158                 if (cur->fp == iop)
 159                         break;
 160         if (cur == NULL)
 161                 return (-1);
 162
 163         do {
 164                 pid = waitpid(cur->pid, &pstat, 0);
 165         } while (pid == -1 && errno == EINTR);
 166
 167         /* Remove the entry from the linked list. */
 168         if (last == NULL)
 169                 pidlist = cur->next;
 170         else
 171                 last->next = cur->next;
 172         free(cur);
 173
 174         return (pid == -1 ? -1 : pstat);
 175 }