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
52 pid_t childpid; /* child's process ID */
53
54 static SIGTYPE (*oldsigquit)(); /* old value of quit signal */
55 static SIGTYPE (*oldsigtstp)(); /* old value of terminal stop signal */
56
57 static pid_t myfork(void);
58 static 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*/
66 int
execute(char * path,...)67 execute(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
111 static pid_t
myfork(void)112 myfork(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
137 static int
join(pid_t p)138 join(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