xref: /freebsd/usr.bin/apply/apply.c (revision 3cbb4cc200f8a0ad7ed08233425ea54524a21f1c)
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 ISMAGICNO(p) \
59 	    (p)[0] == magic && isdigit((unsigned char)(p)[1]) && (p)[1] != '0'
60 
61 static int	exec_shell(const char *, const char *, const char *);
62 static void	usage(void);
63 
64 int
65 main(int argc, char *argv[])
66 {
67 	struct sbuf *cmdbuf;
68 	long arg_max;
69 	int ch, debug, i, magic, n, nargs, rval;
70 	size_t cmdsize;
71 	char buf[4];
72 	char *cmd, *name, *p, *shell, *slashp, *tmpshell;
73 
74 	debug = 0;
75 	magic = '%';		/* Default magic char is `%'. */
76 	nargs = -1;
77 	while ((ch = getopt(argc, argv, "a:d0123456789")) != -1)
78 		switch (ch) {
79 		case 'a':
80 			if (optarg[0] == '\0' || optarg[1] != '\0')
81 				errx(1,
82 				    "illegal magic character specification");
83 			magic = optarg[0];
84 			break;
85 		case 'd':
86 			debug = 1;
87 			break;
88 		case '0': case '1': case '2': case '3': case '4':
89 		case '5': case '6': case '7': case '8': case '9':
90 			if (nargs != -1)
91 				errx(1,
92 				    "only one -# argument may be specified");
93 			nargs = optopt - '0';
94 			break;
95 		default:
96 			usage();
97 		}
98 	argc -= optind;
99 	argv += optind;
100 
101 	if (argc < 2)
102 		usage();
103 
104 	/*
105 	 * The command to run is argv[0], and the args are argv[1..].
106 	 * Look for %digit references in the command, remembering the
107 	 * largest one.
108 	 */
109 	for (n = 0, p = argv[0]; *p != '\0'; ++p)
110 		if (ISMAGICNO(p)) {
111 			++p;
112 			if (p[0] - '0' > n)
113 				n = p[0] - '0';
114 		}
115 
116 	/*
117 	 * Figure out the shell and name arguments to pass to execl()
118 	 * in exec_shell().  Always malloc() shell and just set name
119 	 * to point at the last part of shell if there are any backslashes,
120 	 * otherwise just set it to point at the space malloc()'d.  If
121 	 * SHELL environment variable exists, replace contents of
122 	 * shell with it.
123 	 */
124 	shell = name = NULL;
125 	tmpshell = getenv("SHELL");
126 	shell = (tmpshell != NULL) ? strdup(tmpshell) : strdup(_PATH_BSHELL);
127 	if (shell == NULL)
128 		err(1, "strdup() failed");
129 	slashp = strrchr(shell, '/');
130 	name = (slashp != NULL) ? slashp + 1 : shell;
131 
132 	/*
133 	 * If there were any %digit references, then use those, otherwise
134 	 * build a new command string with sufficient %digit references at
135 	 * the end to consume (nargs) arguments each time round the loop.
136 	 * Allocate enough space to hold the maximum command.  Save the
137 	 * size to pass to snprintf().
138 	 */
139 	if (n == 0) {
140 		cmdsize = strlen(argv[0]) + 9 * (sizeof(" %1") - 1) + 1;
141 		if ((cmd = malloc(cmdsize)) == NULL)
142 			err(1, NULL);
143 		strlcpy(cmd, argv[0], cmdsize);
144 
145 		/* If nargs not set, default to a single argument. */
146 		if (nargs == -1)
147 			nargs = 1;
148 
149 		for (i = 1; i <= nargs; i++) {
150 			snprintf(buf, sizeof(buf), " %c%d", magic, i);
151 			strlcat(cmd, buf, cmdsize);
152 		}
153 
154 		/*
155 		 * If nargs set to the special value 0, eat a single
156 		 * argument for each command execution.
157 		 */
158 		if (nargs == 0)
159 			nargs = 1;
160 	} else {
161 		if ((cmd = strdup(argv[0])) == NULL)
162 			err(1, NULL);
163 		nargs = n;
164 	}
165 
166 	cmdbuf = sbuf_new(NULL, NULL, 1024, SBUF_AUTOEXTEND);
167 	if (cmdbuf == NULL)
168 		err(1, NULL);
169 
170 	arg_max = sysconf(_SC_ARG_MAX);
171 
172 	/*
173 	 * (argc) and (argv) are still offset by one to make it simpler to
174 	 * expand %digit references.  At the end of the loop check for (argc)
175 	 * equals 1 means that all the (argv) has been consumed.
176 	 */
177 	for (rval = 0; argc > nargs; argc -= nargs, argv += nargs) {
178 		sbuf_clear(cmdbuf);
179 		sbuf_cat(cmdbuf, "exec ");
180 		/* Expand command argv references. */
181 		for (p = cmd; *p != '\0'; ++p) {
182 			if (ISMAGICNO(p)) {
183 				if (sbuf_cat(cmdbuf, argv[(++p)[0] - '0'])
184 				    == -1)
185 					errc(1, ENOMEM, "sbuf");
186 			} else {
187 				if (sbuf_putc(cmdbuf, *p) == -1)
188 					errc(1, ENOMEM, "sbuf");
189 			}
190 			if (sbuf_len(cmdbuf) > arg_max)
191 				errc(1, E2BIG, NULL);
192 		}
193 
194 		/* Terminate the command string. */
195 		sbuf_finish(cmdbuf);
196 
197 		/* Run the command. */
198 		if (debug)
199 			(void)printf("%s\n", sbuf_data(cmdbuf));
200 		else
201 			if (exec_shell(sbuf_data(cmdbuf), shell, name))
202 				rval = 1;
203 	}
204 
205 	if (argc != 1)
206 		errx(1, "expecting additional argument%s after \"%s\"",
207 		    (nargs - argc) ? "s" : "", argv[argc - 1]);
208 	free(cmd);
209 	sbuf_delete(cmdbuf);
210 	free(shell);
211 	exit(rval);
212 }
213 
214 /*
215  * exec_shell --
216  * 	Execute a shell command using passed use_shell and use_name
217  * 	arguments.
218  */
219 static int
220 exec_shell(const char *command, const char *use_shell, const char *use_name)
221 {
222 	pid_t pid;
223 	int omask, pstat;
224 	sig_t intsave, quitsave;
225 
226 	if (!command)		/* just checking... */
227 		return(1);
228 
229 	omask = sigblock(sigmask(SIGCHLD));
230 	switch(pid = vfork()) {
231 	case -1:			/* error */
232 		err(1, "vfork");
233 	case 0:				/* child */
234 		(void)sigsetmask(omask);
235 		execl(use_shell, use_name, "-c", command, (char *)NULL);
236 		warn("%s", use_shell);
237 		_exit(1);
238 	}
239 	intsave = signal(SIGINT, SIG_IGN);
240 	quitsave = signal(SIGQUIT, SIG_IGN);
241 	pid = waitpid(pid, &pstat, 0);
242 	(void)sigsetmask(omask);
243 	(void)signal(SIGINT, intsave);
244 	(void)signal(SIGQUIT, quitsave);
245 	return(pid == -1 ? -1 : pstat);
246 }
247 
248 static void
249 usage(void)
250 {
251 
252 	(void)fprintf(stderr,
253 	"usage: apply [-a magic] [-d] [-0123456789] command arguments ...\n");
254 	exit(1);
255 }
256