usr/src/lib/libmail/common/popenvp.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 /*
  33  *  These routines are based on the standard UNIX stdio popen/pclose
  34  *  routines. This version takes an argv[][] argument instead of a string
  35  *  to be passed to the shell. The routine execvp() is used to call the
  36  *  program, hence the name popenvp() and the argument types.
  37  *
  38  *  This routine avoids an extra shell completely, along with not having
  39  *  to worry about quoting conventions in strings that have spaces,
  40  *  quotes, etc.
  41  */
  42
  43 #include <sys/types.h>
  44 #include <assert.h>
  45 #include <string.h>
  46 #include "libmail.h"
  47 #include <sys/wait.h>
  48 #include <stdio.h>
  49 #include <fcntl.h>
  50 #include <signal.h>
  51 #include <errno.h>
  52
  53 #define tst(a, b) (*mode == 'r'? (b) : (a))
  54 #define RDR     0
  55 #define WTR     1
  56
  57 #include <unistd.h>
  58 static pid_t popen_pid[20];
  59
  60 /* Functions calling popenvp() should ensure 'file' is non-NULL */
  61
  62 FILE *
  63 popenvp(char *file, char **argv, char *mode, int resetid)
  64 {
  65         int     p[2];
  66         int myside, yourside;
  67         pid_t pid;
  68
  69         assert(file != NULL);
  70         if (pipe(p) < 0)
  71                 return (NULL);
  72         myside = tst(p[WTR], p[RDR]);
  73         yourside = tst(p[RDR], p[WTR]);
  74         if ((pid = fork()) == 0) {
  75                 /* myside and yourside reverse roles in child */
  76                 int     stdio;
  77
  78                 if (resetid) {
  79                         (void) setgid(getgid());
  80                         (void) setuid(getuid());
  81                 }
  82                 stdio = tst(0, 1);
  83                 (void) close(myside);
  84                 (void) close(stdio);
  85                 (void) fcntl(yourside, F_DUPFD, stdio);
  86                 (void) close(yourside);
  87                 (void) execvp(file, argv);
  88                 (void) fprintf(stderr, "exec of \"%s\" failed: %s\n",
  89                     file, strerror(errno));
  90                 (void) fflush(stderr);
  91                 _exit(1);
  92         }
  93         if (pid == (pid_t)-1)
  94                 return (NULL);
  95         popen_pid[myside] = pid;
  96         (void) close(yourside);
  97         return (fdopen(myside, mode));
  98 }
  99
 100 int
 101 pclosevp(FILE *ptr)
 102 {
 103         int f;
 104         pid_t r;
 105         int status;
 106         void (*hstat)(int), (*istat)(int), (*qstat)(int);
 107
 108         f = fileno(ptr);
 109         (void) fclose(ptr);
 110         istat = signal(SIGINT, SIG_IGN);
 111         qstat = signal(SIGQUIT, SIG_IGN);
 112         hstat = signal(SIGHUP, SIG_IGN);
 113         do {
 114                 r = wait(&status);
 115         } while (r != popen_pid[f] && r != (pid_t)-1);
 116
 117         if (r == (pid_t)-1)
 118                 status = -1;
 119         (void) signal(SIGINT, istat);
 120         (void) signal(SIGQUIT, qstat);
 121         (void) signal(SIGHUP, hstat);
 122         return (status);
 123 }