xref: /freebsd/usr.bin/apply/apply.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 #if 0
36 #ifndef lint
37 static char sccsid[] = "@(#)apply.c	8.4 (Berkeley) 4/4/94";
38 #endif
39 #endif
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include <sys/types.h>
45 #include <sys/sbuf.h>
46 #include <sys/wait.h>
47 
48 #include <ctype.h>
49 #include <err.h>
50 #include <errno.h>
51 #include <paths.h>
52 #include <signal.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <unistd.h>
57 
58 #define EXEC	"exec "
59 
60 static int	exec_shell(const char *, const char *, const char *);
61 static void	usage(void);
62 
63 int
64 main(int argc, char *argv[])
65 {
66 	struct sbuf *cmdbuf;
67 	long arg_max;
68 	int ch, debug, i, magic, n, nargs, offset, rval;
69 	size_t cmdsize;
70 	char *cmd, *name, *p, *shell, *slashp, *tmpshell;
71 
72 	debug = 0;
73 	magic = '%';		/* Default magic char is `%'. */
74 	nargs = -1;
75 	while ((ch = getopt(argc, argv, "a:d0123456789")) != -1)
76 		switch (ch) {
77 		case 'a':
78 			if (optarg[1] != '\0')
79 				errx(1,
80 				    "illegal magic character specification");
81 			magic = optarg[0];
82 			break;
83 		case 'd':
84 			debug = 1;
85 			break;
86 		case '0': case '1': case '2': case '3': case '4':
87 		case '5': case '6': case '7': case '8': case '9':
88 			if (nargs != -1)
89 				errx(1,
90 				    "only one -# argument may be specified");
91 			nargs = optopt - '0';
92 			break;
93 		default:
94 			usage();
95 		}
96 	argc -= optind;
97 	argv += optind;
98 
99 	if (argc < 2)
100 		usage();
101 
102 	/*
103 	 * The command to run is argv[0], and the args are argv[1..].
104 	 * Look for %digit references in the command, remembering the
105 	 * largest one.
106 	 */
107 	for (n = 0, p = argv[0]; *p != '\0'; ++p)
108 		if (p[0] == magic && isdigit(p[1]) && p[1] != '0') {
109 			++p;
110 			if (p[0] - '0' > n)
111 				n = p[0] - '0';
112 		}
113 
114 	/*
115 	 * Figure out the shell and name arguments to pass to execl()
116 	 * in exec_shell().  Always malloc() shell and just set name
117 	 * to point at the last part of shell if there are any backslashes,
118 	 * otherwise just set it to point at the space malloc()'d.  If
119 	 * SHELL environment variable exists, replace contents of
120 	 * shell with it.
121 	 */
122 	shell = name = NULL;
123 	tmpshell = getenv("SHELL");
124 	shell = (tmpshell != NULL) ? strdup(tmpshell) : strdup(_PATH_BSHELL);
125 	if (shell == NULL)
126 		err(1, "strdup() failed");
127 	slashp = strrchr(shell, '/');
128 	name = (slashp != NULL) ? slashp + 1 : shell;
129 
130 	/*
131 	 * If there were any %digit references, then use those, otherwise
132 	 * build a new command string with sufficient %digit references at
133 	 * the end to consume (nargs) arguments each time round the loop.
134 	 * Allocate enough space to hold the maximum command.  Save the
135 	 * size to pass to snprintf().
136 	 */
137 	cmdsize = sizeof(EXEC) - 1 + strlen(argv[0])
138 	    + 9 * (sizeof(" %1") - 1) + 1;
139 	if ((cmd = malloc(cmdsize)) == NULL)
140 		err(1, NULL);
141 
142 	if (n == 0) {
143 		/* If nargs not set, default to a single argument. */
144 		if (nargs == -1)
145 			nargs = 1;
146 
147 		p = cmd;
148 		offset = snprintf(cmd, cmdsize, EXEC "%s", argv[0]);
149 		if ((size_t)offset >= cmdsize)
150 			errx(1, "snprintf() failed");
151 		p += offset;
152 		cmdsize -= offset;
153 		for (i = 1; i <= nargs; i++) {
154 			offset = snprintf(p, cmdsize, " %c%d", magic, i);
155 			if ((size_t)offset >= cmdsize)
156 				errx(1, "snprintf() failed");
157 			p += offset;
158 			cmdsize -= offset;
159 		}
160 
161 		/*
162 		 * If nargs set to the special value 0, eat a single
163 		 * argument for each command execution.
164 		 */
165 		if (nargs == 0)
166 			nargs = 1;
167 	} else {
168 		offset = snprintf(cmd, cmdsize, EXEC "%s", argv[0]);
169 		if ((size_t)offset >= cmdsize)
170 			errx(1, "snprintf() failed");
171 		nargs = n;
172 	}
173 
174 	cmdbuf = sbuf_new(NULL, NULL, 1024, SBUF_AUTOEXTEND);
175 	if (cmdbuf == NULL)
176 		err(1, NULL);
177 
178 	arg_max = sysconf(_SC_ARG_MAX);
179 
180 	/*
181 	 * (argc) and (argv) are still offset by one to make it simpler to
182 	 * expand %digit references.  At the end of the loop check for (argc)
183 	 * equals 1 means that all the (argv) has been consumed.
184 	 */
185 	for (rval = 0; argc > nargs; argc -= nargs, argv += nargs) {
186 		sbuf_clear(cmdbuf);
187 		/* Expand command argv references. */
188 		for (p = cmd; *p != '\0'; ++p) {
189 			if (p[0] == magic && isdigit(p[1]) && p[1] != '0') {
190 				if (sbuf_cat(cmdbuf, argv[(++p)[0] - '0'])
191 				    == -1)
192 					errc(1, ENOMEM, "sbuf");
193 			} else {
194 				if (sbuf_putc(cmdbuf, *p) == -1)
195 					errc(1, ENOMEM, "sbuf");
196 			}
197 			if (sbuf_len(cmdbuf) > arg_max)
198 				errc(1, E2BIG, NULL);
199 		}
200 
201 		/* Terminate the command string. */
202 		sbuf_finish(cmdbuf);
203 
204 		/* Run the command. */
205 		if (debug)
206 			(void)printf("%s\n", sbuf_data(cmdbuf));
207 		else
208 			if (exec_shell(sbuf_data(cmdbuf), shell, name))
209 				rval = 1;
210 	}
211 
212 	if (argc != 1)
213 		errx(1, "expecting additional argument%s after \"%s\"",
214 		    (nargs - argc) ? "s" : "", argv[argc - 1]);
215 	free(cmd);
216 	sbuf_delete(cmdbuf);
217 	free(shell);
218 	exit(rval);
219 }
220 
221 /*
222  * exec_shell --
223  * 	Execute a shell command using passed use_shell and use_name
224  * 	arguments.
225  */
226 static int
227 exec_shell(const char *command, const char *use_shell, const char *use_name)
228 {
229 	pid_t pid;
230 	int omask, pstat;
231 	sig_t intsave, quitsave;
232 
233 	if (!command)		/* just checking... */
234 		return(1);
235 
236 	omask = sigblock(sigmask(SIGCHLD));
237 	switch(pid = vfork()) {
238 	case -1:			/* error */
239 		err(1, "vfork");
240 	case 0:				/* child */
241 		(void)sigsetmask(omask);
242 		execl(use_shell, use_name, "-c", command, (char *)NULL);
243 		warn("%s", use_shell);
244 		_exit(1);
245 	}
246 	intsave = signal(SIGINT, SIG_IGN);
247 	quitsave = signal(SIGQUIT, SIG_IGN);
248 	pid = waitpid(pid, &pstat, 0);
249 	(void)sigsetmask(omask);
250 	(void)signal(SIGINT, intsave);
251 	(void)signal(SIGQUIT, quitsave);
252 	return(pid == -1 ? -1 : pstat);
253 }
254 
255 static void
256 usage(void)
257 {
258 
259 	(void)fprintf(stderr,
260 	"usage: apply [-a magic] [-d] [-0123456789] command arguments ...\n");
261 	exit(1);
262 }
263