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 2004 Sun Microsystems, Inc.  All rights reserved.
28 * Use is subject to license terms.
29 */
30
31#pragma ident	"%Z%%M%	%I%	%E% SMI"
32
33/*
34 *	cscope - interactive C symbol cross-reference
35 *
36 *	process execution functions
37 */
38
39#include "global.h"
40#include <sys/types.h>
41#include <sys/wait.h>
42#include <stdarg.h>
43#include <unistd.h>
44#include <stdlib.h>
45#include <stdio.h>
46#include <libgen.h>
47
48#define	getdtablesize()	_NFILE
49
50#define	MAXARGS	100	/* maximum number of arguments to executed command */
51
52pid_t	childpid;	/* child's process ID */
53
54static	SIGTYPE	(*oldsigquit)();	/* old value of quit signal */
55static	SIGTYPE	(*oldsigtstp)();	/* old value of terminal stop signal */
56
57static pid_t myfork(void);
58static int join(pid_t p);
59
60/*
61 * execute forks and executes a program or shell script, waits for it to
62 * finish, and returns its exit code.
63 */
64
65/*VARARGS0*/
66int
67execute(char *path, ...)
68{
69	va_list	ap;
70	char	*args[MAXARGS + 1];
71	int	exitcode;
72	int	i;
73	char	msg[MSGLEN + 1];
74	pid_t	p;
75
76	/* fork and exec the program or shell script */
77	exitcurses();
78	if ((p = myfork()) == 0) {
79
80		/* close all files except stdin, stdout, and stderr */
81		for (i = 3; i < getdtablesize() && close(i) == 0; ++i) {
82			;
83		}
84		/* execute the program or shell script */
85		va_start(ap, path);
86		for (i = 0; i < MAXARGS &&
87		    (args[i] = va_arg(ap, char *)) != NULL; ++i) {
88		}
89		va_end(ap);
90		args[i] = NULL;			/* in case MAXARGS reached */
91		args[0] = basename(args[0]);
92		(void) execvp(path, args);	/* returns only on failure */
93		(void) sprintf(msg, "\ncscope: cannot execute %s", path);
94		(void) perror(msg);	/* display the reason */
95		askforreturn();	 /* wait until the user sees the message */
96		exit(1);		/* exit the child */
97	} else {
98		exitcode = join(p);	/* parent */
99	}
100	if (noacttimeout) {
101		(void) fprintf(stderr,
102		    "cscope: no activity time out--exiting\n");
103		myexit(SIGALRM);
104	}
105	entercurses();
106	return (exitcode);
107}
108
109/* myfork acts like fork but also handles signals */
110
111static pid_t
112myfork(void)
113{
114	pid_t	p;		/* process number */
115
116	oldsigtstp = signal(SIGTSTP, SIG_DFL);
117	/* the parent ignores the interrupt and quit signals */
118	if ((p = fork()) > 0) {
119		childpid = p;
120		oldsigquit = signal(SIGQUIT, SIG_IGN);
121	}
122	/* so they can be used to stop the child */
123	else if (p == 0) {
124		(void) signal(SIGINT, SIG_DFL);
125		(void) signal(SIGQUIT, SIG_DFL);
126		(void) signal(SIGHUP, SIG_DFL);	/* restore hangup default */
127	}
128	/* check for fork failure */
129	if (p == -1) {
130		myperror("Cannot fork");
131	}
132	return (p);
133}
134
135/* join is the compliment of fork */
136
137static int
138join(pid_t p)
139{
140	int	status;
141	pid_t	w;
142
143	/* wait for the correct child to exit */
144	do {
145		w = wait(&status);
146	} while (p != -1 && w != p);
147	childpid = 0;
148
149	/* restore signal handling */
150	(void) signal(SIGQUIT, oldsigquit);
151	(void) signal(SIGTSTP, oldsigtstp);
152	/* return the child's exit code */
153	return (status >> 8);
154}
155