xref: /illumos-gate/usr/src/lib/libmail/common/popenvp.c (revision 1a2d662a91cee3bf82f41cd47c7ae6f3825d9db2)
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 /*
31  *  These routines are based on the standard UNIX stdio popen/pclose
32  *  routines. This version takes an argv[][] argument instead of a string
33  *  to be passed to the shell. The routine execvp() is used to call the
34  *  program, hence the name popenvp() and the argument types.
35  *
36  *  This routine avoids an extra shell completely, along with not having
37  *  to worry about quoting conventions in strings that have spaces,
38  *  quotes, etc.
39  */
40 
41 #include <sys/types.h>
42 #include <assert.h>
43 #include <string.h>
44 #include "libmail.h"
45 #include <sys/wait.h>
46 #include <stdio.h>
47 #include <fcntl.h>
48 #include <signal.h>
49 #include <errno.h>
50 
51 #define	tst(a, b) (*mode == 'r'? (b) : (a))
52 #define	RDR	0
53 #define	WTR	1
54 
55 #include <unistd.h>
56 static pid_t popen_pid[20];
57 
58 /* Functions calling popenvp() should ensure 'file' is non-NULL */
59 
60 FILE *
61 popenvp(char *file, char **argv, char *mode, int resetid)
62 {
63 	int	p[2];
64 	int myside, yourside;
65 	pid_t pid;
66 
67 	assert(file != NULL);
68 	if (pipe(p) < 0)
69 		return (NULL);
70 	myside = tst(p[WTR], p[RDR]);
71 	yourside = tst(p[RDR], p[WTR]);
72 	if ((pid = fork()) == 0) {
73 		/* myside and yourside reverse roles in child */
74 		int	stdio;
75 
76 		if (resetid) {
77 			(void) setgid(getgid());
78 			(void) setuid(getuid());
79 		}
80 		stdio = tst(0, 1);
81 		(void) close(myside);
82 		(void) close(stdio);
83 		(void) fcntl(yourside, F_DUPFD, stdio);
84 		(void) close(yourside);
85 		(void) execvp(file, argv);
86 		(void) fprintf(stderr, "exec of \"%s\" failed: %s\n",
87 		    file, strerror(errno));
88 		(void) fflush(stderr);
89 		_exit(1);
90 	}
91 	if (pid == (pid_t)-1)
92 		return (NULL);
93 	popen_pid[myside] = pid;
94 	(void) close(yourside);
95 	return (fdopen(myside, mode));
96 }
97 
98 int
99 pclosevp(FILE *ptr)
100 {
101 	int f;
102 	pid_t r;
103 	int status;
104 	void (*hstat)(int), (*istat)(int), (*qstat)(int);
105 
106 	f = fileno(ptr);
107 	(void) fclose(ptr);
108 	istat = signal(SIGINT, SIG_IGN);
109 	qstat = signal(SIGQUIT, SIG_IGN);
110 	hstat = signal(SIGHUP, SIG_IGN);
111 	do {
112 		r = wait(&status);
113 	} while (r != popen_pid[f] && r != (pid_t)-1);
114 
115 	if (r == (pid_t)-1)
116 		status = -1;
117 	(void) signal(SIGINT, istat);
118 	(void) signal(SIGQUIT, qstat);
119 	(void) signal(SIGHUP, hstat);
120 	return (status);
121 }
122