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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*	Copyright (c) 1988 AT&T	*/
23 /*	  All Rights Reserved  	*/
24 
25 
26 /*
27  * Copyright (c) 1999 by Sun Microsystems, Inc.
28  * All rights reserved.
29  */
30 
31 #pragma ident	"%Z%%M%	%I%	%E% SMI"
32 
33 #include <fcntl.h>
34 #include <sys/types.h>
35 #include <sys/wait.h>
36 #include <unistd.h>
37 #include <stdlib.h>
38 #include <stdio.h>
39 #include <libgen.h>
40 #include "global.h"	/* pid_t, SIGTYPE, shell, and basename() */
41 
42 #define	tst(a, b) (*mode == 'r'? (b) : (a))
43 #define	RDR	0
44 #define	WTR	1
45 
46 static pid_t popen_pid[20];
47 static SIGTYPE (*tstat)();
48 
49 FILE *
mypopen(char * cmd,char * mode)50 mypopen(char *cmd, char *mode)
51 {
52 	int	p[2];
53 	pid_t *poptr;
54 	int myside, yourside;
55 	pid_t pid;
56 
57 	if (pipe(p) < 0)
58 		return (NULL);
59 	myside = tst(p[WTR], p[RDR]);
60 	yourside = tst(p[RDR], p[WTR]);
61 	if ((pid = fork()) > 0) {
62 		tstat = signal(SIGTSTP, SIG_DFL);
63 	} else if (pid == 0) {
64 		/* myside and yourside reverse roles in child */
65 		int	stdio;
66 
67 		/* close all pipes from other popen's */
68 		for (poptr = popen_pid; poptr < popen_pid+20; poptr++) {
69 			if (*poptr)
70 				(void) close(poptr - popen_pid);
71 		}
72 		stdio = tst(0, 1);
73 		(void) close(myside);
74 		(void) close(stdio);
75 		(void) fcntl(yourside, F_DUPFD, stdio);
76 		(void) close(yourside);
77 		(void) execlp(shell, basename(shell), "-c", cmd, 0);
78 		_exit(1);
79 	}
80 	if (pid == -1)
81 		return (NULL);
82 	popen_pid[myside] = pid;
83 	(void) close(yourside);
84 	return (fdopen(myside, mode));
85 }
86 
87 int
mypclose(FILE * ptr)88 mypclose(FILE *ptr)
89 {
90 	int f;
91 	pid_t r;
92 	int status;
93 	SIGTYPE (*hstat)(), (*istat)(), (*qstat)();
94 
95 	f = fileno(ptr);
96 	(void) fclose(ptr);
97 	istat = signal(SIGINT, SIG_IGN);
98 	qstat = signal(SIGQUIT, SIG_IGN);
99 	hstat = signal(SIGHUP, SIG_IGN);
100 	while ((r = wait(&status)) != popen_pid[f] && r != -1) {
101 	}
102 	if (r == -1)
103 		status = -1;
104 	(void) signal(SIGINT, istat);
105 	(void) signal(SIGQUIT, qstat);
106 	(void) signal(SIGHUP, hstat);
107 	(void) signal(SIGTSTP, tstat);
108 	/* mark this pipe closed */
109 	popen_pid[f] = 0;
110 	return (status);
111 }
112