1/* $NetBSD: apply.c,v 1.19 2016/03/12 22:28:04 dholland Exp $ */
2
3/*-
4 * Copyright (c) 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Jan-Simon Pendry.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <sys/cdefs.h>
36#ifndef lint
37#if 0
38static char sccsid[] = "@(#)apply.c 8.4 (Berkeley) 4/4/94";
39#else
40__RCSID("$NetBSD: apply.c,v 1.19 2016/03/12 22:28:04 dholland Exp $");
41#endif
42#endif /* not lint */
43
44#include <sys/wait.h>
45
46#include <ctype.h>
47#include <err.h>
48#include <paths.h>
49#include <signal.h>
50#include <stdio.h>
51#include <stdlib.h>
52#include <string.h>
53#include <unistd.h>
54
55static __dead void usage(void);
56static int shell_system(const char *);
57
58int
59main(int argc, char *argv[])
60{
61 size_t clen, l;
62 int ch, debug, i, magic, n, nargs, rval;
63 char *c, *cmd, *p, *q, *nc;
64
65 (void)setprogname(argv[0]); /* for portability */
66
67 /* Option defaults */
68 debug = 0;
69 magic = '%';
70 nargs = -1;
71
72 while ((ch = getopt(argc, argv, "a:d0123456789")) != -1) {
73 switch (ch) {
74 case 'a':
75 if (optarg[1] != '\0')
76 errx(EXIT_FAILURE,
77 "Illegal magic character specification.");
78 magic = optarg[0];
79 break;
80 case 'd':
81 debug = 1;
82 break;
83 case '0': case '1': case '2': case '3': case '4':
84 case '5': case '6': case '7': case '8': case '9':
85 if (nargs != -1)
86 errx(EXIT_FAILURE,
87 "Only one -# argument may be specified.");
88 nargs = optopt - '0';
89 break;
90 default:
91 usage();
92 }
93 }
94 argc -= optind;
95 argv += optind;
96
97 if (argc < 2)
98 usage();
99
100 /*
101 * The command to run is now argv[0], and the args are argv[1+].
102 * Look for %digit references in the command, remembering the
103 * largest one.
104 */
105 n = 0;
106 for (p = argv[0]; p[0] != '\0'; ++p) {
107 if (p[0] == magic && p[1] != '\0' &&
108 isdigit((unsigned char)p[1]) && p[1] != '0') {
109 ++p;
110 if (p[0] - '0' > n)
111 n = p[0] - '0';
112 }
113 }
114
115 /*
116 * If there were any %digit references, then use those, otherwise
117 * build a new command string with sufficient %digit references at
118 * the end to consume (nargs) arguments each time round the loop.
119 * Allocate enough space to hold the maximum command.
120 */
121 if ((cmd = malloc(sizeof("exec ") - 1 +
122 strlen(argv[0]) + 9 * (sizeof(" %1") - 1) + 1)) == NULL)
123 err(EXIT_FAILURE, "malloc");
124
125 if (n == 0) {
126 /* If nargs not set, default to a single argument. */
127 if (nargs == -1)
128 nargs = 1;
129
130 p = cmd;
131 p += sprintf(cmd, "exec %s", argv[0]);
132 for (i = 1; i <= nargs; i++)
133 p += sprintf(p, " %c%d", magic, i);
134
135 /*
136 * If nargs set to the special value 0, eat a single
137 * argument for each command execution.
138 */
139 if (nargs == 0)
140 nargs = 1;
141 } else {
142 (void)sprintf(cmd, "exec %s", argv[0]);
143 nargs = n;
144 }
145
146 /*
147 * Grab some space in which to build the command. Allocate
148 * as necessary later, but no reason to build it up slowly
149 * for the normal case.
150 */
151 if ((c = malloc(clen = 1024)) == NULL)
152 err(EXIT_FAILURE, "malloc");
153
154 /*
155 * (argc) and (argv) are still offset by one to make it simpler to
156 * expand %digit references. At the end of the loop check for (argc)
157 * equals 1 means that all the (argv) has been consumed.
158 */
159 for (rval = 0; argc > nargs; argc -= nargs, argv += nargs) {
160 /*
161 * Find a max value for the command length, and ensure
162 * there's enough space to build it.
163 */
164 for (l = strlen(cmd), i = 0; i < nargs; i++)
165 l += strlen(argv[i+1]);
166 if (l > clen) {
167 nc = realloc(c, l);
168 if (nc == NULL)
169 err(EXIT_FAILURE, "malloc");
170 c = nc;
171 clen = l;
172 }
173
174 /* Expand command argv references. */
175 for (p = cmd, q = c; *p != '\0'; ++p) {
176 if (p[0] == magic && isdigit((unsigned char)p[1]) &&
177 p[1] != '0')
178 q += sprintf(q, "%s", argv[(++p)[0] - '0']);
179 else
180 *q++ = *p;
181 }
182
183 /* Terminate the command string. */
184 *q = '\0';
185
186 /* Run the command. */
187 if (debug)
188 (void)printf("%s\n", c);
189 else if (shell_system(c))
190 rval = 1;
191 }
192
193 if (argc != 1)
194 errx(EXIT_FAILURE,
195 "Expecting additional argument%s after \"%s\"",
196 (nargs - argc) ? "s" : "", argv[argc - 1]);
197 return rval;
198}
199
200/*
201 * shell_system --
202 * Private version of system(3). Use the user's SHELL environment
203 * variable as the shell to execute.
204 */
205static int
206shell_system(const char *command)
207{
208 static const char *name, *shell;
209 int status;
210 pid_t pid;
211 sigset_t chldmask, omask;
212 sig_t intsave, quitsave;
213
214 if (shell == NULL) {
215 if ((shell = getenv("SHELL")) == NULL)
216 shell = _PATH_BSHELL;
217 if ((name = strrchr(shell, '/')) == NULL)
218 name = shell;
219 else
220 ++name;
221 }
222
223 if (!command) {
224 /* just checking... */
225 return(1);
226 }
227
228 (void)sigemptyset(&chldmask);
229 (void)sigaddset(&chldmask, SIGCHLD);
230 if (sigprocmask(SIG_BLOCK, &chldmask, &omask) == -1)
231 err(EXIT_FAILURE, "sigprocmask");
232
233 switch (pid = fork()) {
234 case -1:
235 /* error */
236 err(EXIT_FAILURE, "fork");
237 /*NOTREACHED*/
238 case 0:
239 /* child */
240 (void)sigprocmask(SIG_SETMASK, &omask, NULL);
241 (void)execl(shell, name, "-c", command, (char *)NULL);
242 warn("%s", shell);
243 _exit(1);
244 /*NOTREACHED*/
245 default:
246 /* parent */
247 intsave = signal(SIGINT, SIG_IGN);
248 quitsave = signal(SIGQUIT, SIG_IGN);
249 pid = waitpid(pid, &status, 0);
250 (void)sigprocmask(SIG_SETMASK, &omask, NULL);
251 (void)signal(SIGINT, intsave);
252 (void)signal(SIGQUIT, quitsave);
253 return pid == -1 ? -1 : status;
254 }
255 /*NOTREACHED*/
256}
257
258static __dead void
259usage(void)
260{
261
262 (void)fprintf(stderr,
263 "usage: %s [-a magic] [-0123456789] command arguments ...\n",
264 getprogname());
265 exit(1);
266}
