xref: /freebsd/usr.bin/apply/apply.c (revision 031beb4e239bfce798af17f5fe8dba8bcaf13d99)
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 #include <sys/types.h>
43 #include <sys/sbuf.h>
44 #include <sys/wait.h>
45 
46 #include <ctype.h>
47 #include <err.h>
48 #include <errno.h>
49 #include <paths.h>
50 #include <signal.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <unistd.h>
55 
56 #define ISMAGICNO(p) \
57 	    (p)[0] == magic && isdigit((unsigned char)(p)[1]) && (p)[1] != '0'
58 
59 static int	exec_shell(const char *, const char *, const char *);
60 static void	usage(void);
61 
62 int
63 main(int argc, char *argv[])
64 {
65 	struct sbuf *cmdbuf;
66 	long arg_max;
67 	int ch, debug, i, magic, n, nargs, rval;
68 	size_t cmdsize;
69 	char buf[4];
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[0] == '\0' || 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 (ISMAGICNO(p)) {
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 	if (n == 0) {
138 		cmdsize = strlen(argv[0]) + 9 * (sizeof(" %1") - 1) + 1;
139 		if ((cmd = malloc(cmdsize)) == NULL)
140 			err(1, NULL);
141 		strlcpy(cmd, argv[0], cmdsize);
142 
143 		/* If nargs not set, default to a single argument. */
144 		if (nargs == -1)
145 			nargs = 1;
146 
147 		for (i = 1; i <= nargs; i++) {
148 			snprintf(buf, sizeof(buf), " %c%d", magic, i);
149 			strlcat(cmd, buf, cmdsize);
150 		}
151 
152 		/*
153 		 * If nargs set to the special value 0, eat a single
154 		 * argument for each command execution.
155 		 */
156 		if (nargs == 0)
157 			nargs = 1;
158 	} else {
159 		if ((cmd = strdup(argv[0])) == NULL)
160 			err(1, NULL);
161 		nargs = n;
162 	}
163 
164 	cmdbuf = sbuf_new(NULL, NULL, 1024, SBUF_AUTOEXTEND);
165 	if (cmdbuf == NULL)
166 		err(1, NULL);
167 
168 	arg_max = sysconf(_SC_ARG_MAX);
169 
170 	/*
171 	 * (argc) and (argv) are still offset by one to make it simpler to
172 	 * expand %digit references.  At the end of the loop check for (argc)
173 	 * equals 1 means that all the (argv) has been consumed.
174 	 */
175 	for (rval = 0; argc > nargs; argc -= nargs, argv += nargs) {
176 		sbuf_clear(cmdbuf);
177 		if (sbuf_cat(cmdbuf, "exec ") != 0)
178 			err(1, "sbuf");
179 		/* Expand command argv references. */
180 		for (p = cmd; *p != '\0'; ++p) {
181 			if (ISMAGICNO(p)) {
182 				if (sbuf_cat(cmdbuf, argv[*++p - '0']) != 0)
183 					err(1, "sbuf");
184 			} else {
185 				if (sbuf_putc(cmdbuf, *p) != 0)
186 					err(1, "sbuf");
187 			}
188 			if (sbuf_len(cmdbuf) > arg_max)
189 				errc(1, E2BIG, NULL);
190 		}
191 
192 		/* Terminate the command string. */
193 		if (sbuf_finish(cmdbuf) != 0)
194 			err(1, "sbuf");
195 
196 		/* Run the command. */
197 		if (debug)
198 			(void)printf("%s\n", sbuf_data(cmdbuf));
199 		else
200 			if (exec_shell(sbuf_data(cmdbuf), shell, name))
201 				rval = 1;
202 	}
203 
204 	if (argc != 1)
205 		errx(1, "expecting additional argument%s after \"%s\"",
206 		    (nargs - argc) ? "s" : "", argv[argc - 1]);
207 	free(cmd);
208 	sbuf_delete(cmdbuf);
209 	free(shell);
210 	exit(rval);
211 }
212 
213 /*
214  * exec_shell --
215  * 	Execute a shell command using passed use_shell and use_name
216  * 	arguments.
217  */
218 static int
219 exec_shell(const char *command, const char *use_shell, const char *use_name)
220 {
221 	pid_t pid;
222 	int omask, pstat;
223 	sig_t intsave, quitsave;
224 
225 	if (!command)		/* just checking... */
226 		return(1);
227 
228 	omask = sigblock(sigmask(SIGCHLD));
229 	switch(pid = vfork()) {
230 	case -1:			/* error */
231 		err(1, "vfork");
232 	case 0:				/* child */
233 		(void)sigsetmask(omask);
234 		execl(use_shell, use_name, "-c", command, (char *)NULL);
235 		warn("%s", use_shell);
236 		_exit(1);
237 	}
238 	intsave = signal(SIGINT, SIG_IGN);
239 	quitsave = signal(SIGQUIT, SIG_IGN);
240 	pid = waitpid(pid, &pstat, 0);
241 	(void)sigsetmask(omask);
242 	(void)signal(SIGINT, intsave);
243 	(void)signal(SIGQUIT, quitsave);
244 	return(pid == -1 ? -1 : pstat);
245 }
246 
247 static void
248 usage(void)
249 {
250 
251 	(void)fprintf(stderr,
252 	"usage: apply [-a magic] [-d] [-0123456789] command arguments ...\n");
253 	exit(1);
254 }
255