xref: /freebsd/usr.bin/apply/apply.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
1 /*-
2  * Copyright (c) 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Jan-Simon Pendry.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #if 0
38 #ifndef lint
39 static char sccsid[] = "@(#)apply.c	8.4 (Berkeley) 4/4/94";
40 #endif
41 #endif
42 
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
45 
46 #include <sys/types.h>
47 #include <sys/wait.h>
48 
49 #include <ctype.h>
50 #include <err.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 *, char *, char *);
61 static void	usage(void);
62 
63 int
64 main(int argc, char *argv[]) {
65 	int ch, debug, i, magic, n, nargs, offset, rval;
66 	size_t clen, cmdsize, l;
67 	char *c, *cmd, *name, *p, *q, *shell, *slashp, *tmpshell;
68 
69 	debug = 0;
70 	magic = '%';		/* Default magic char is `%'. */
71 	nargs = -1;
72 	while ((ch = getopt(argc, argv, "a:d0123456789")) != -1)
73 		switch (ch) {
74 		case 'a':
75 			if (optarg[1] != '\0')
76 				errx(1,
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(1,
87 				    "only one -# argument may be specified");
88 			nargs = optopt - '0';
89 			break;
90 		default:
91 			usage();
92 		}
93 	argc -= optind;
94 	argv += optind;
95 
96 	if (argc < 2)
97 		usage();
98 
99 	/*
100 	 * The command to run is argv[0], and the args are argv[1..].
101 	 * Look for %digit references in the command, remembering the
102 	 * largest one.
103 	 */
104 	for (n = 0, p = argv[0]; *p != '\0'; ++p)
105 		if (p[0] == magic && isdigit(p[1]) && p[1] != '0') {
106 			++p;
107 			if (p[0] - '0' > n)
108 				n = p[0] - '0';
109 		}
110 
111 	/*
112 	 * Figure out the shell and name arguments to pass to execl()
113 	 * in exec_shell().  Always malloc() shell and just set name
114 	 * to point at the last part of shell if there are any backslashes,
115 	 * otherwise just set it to point at the space malloc()'d.  If
116 	 * SHELL environment variable exists, replace contents of
117 	 * shell with it.
118 	 */
119 	shell = name = NULL;
120 	tmpshell = getenv("SHELL");
121 	shell = (tmpshell != NULL) ? strdup(tmpshell) : strdup(_PATH_BSHELL);
122 	if (shell == NULL)
123 		err(1, "strdup() failed");
124 	slashp = strrchr(shell, '/');
125 	name = (slashp != NULL) ? slashp + 1 : shell;
126 
127 	/*
128 	 * If there were any %digit references, then use those, otherwise
129 	 * build a new command string with sufficient %digit references at
130 	 * the end to consume (nargs) arguments each time round the loop.
131 	 * Allocate enough space to hold the maximum command.  Save the
132 	 * size to pass to snprintf().
133 	 */
134 	cmdsize = sizeof(EXEC) - 1 + strlen(argv[0])
135 	    + 9 * (sizeof(" %1") - 1) + 1;
136 	if ((cmd = malloc(cmdsize)) == NULL)
137 		err(1, NULL);
138 
139 	if (n == 0) {
140 		/* If nargs not set, default to a single argument. */
141 		if (nargs == -1)
142 			nargs = 1;
143 
144 		p = cmd;
145 		offset = snprintf(cmd, cmdsize, EXEC "%s", argv[0]);
146 		if ((size_t)offset >= cmdsize)
147 			err(1, "snprintf() failed");
148 		p += offset;
149 		cmdsize -= offset;
150 		for (i = 1; i <= nargs; i++) {
151 			offset = snprintf(p, cmdsize, " %c%d", magic, i);
152 			if ((size_t)offset >= cmdsize)
153 				err(1, "snprintf() failed");
154 			p += offset;
155 			cmdsize -= offset;
156 		}
157 
158 		/*
159 		 * If nargs set to the special value 0, eat a single
160 		 * argument for each command execution.
161 		 */
162 		if (nargs == 0)
163 			nargs = 1;
164 	} else {
165 		offset = snprintf(cmd, cmdsize, EXEC "%s", argv[0]);
166 		if ((size_t)offset >= cmdsize)
167 			err(1, "snprintf() failed");
168 		nargs = n;
169 	}
170 
171 	/*
172 	 * Grab some space in which to build the command.  Allocate
173 	 * as necessary later, but no reason to build it up slowly
174 	 * for the normal case.
175 	 */
176 	if ((c = malloc(clen = 1024)) == NULL)
177 		err(1, NULL);
178 
179 	/*
180 	 * (argc) and (argv) are still offset by one to make it simpler to
181 	 * expand %digit references.  At the end of the loop check for (argc)
182 	 * equals 1 means that all the (argv) has been consumed.
183 	 */
184 	for (rval = 0; argc > nargs; argc -= nargs, argv += nargs) {
185 		/*
186 		 * Find a max value for the command length, and ensure
187 		 * there's enough space to build it.
188 		 */
189 		for (l = strlen(cmd), i = 0; i < nargs; i++)
190 			l += strlen(argv[i+1]);
191 		if (l > clen && (c = realloc(c, clen = l)) == NULL)
192 			err(1, NULL);
193 
194 		/* Expand command argv references. */
195 		for (p = cmd, q = c; *p != '\0'; ++p)
196 			if (p[0] == magic && isdigit(p[1]) && p[1] != '0') {
197 				offset = snprintf(q, l, "%s",
198 				    argv[(++p)[0] - '0']);
199 				if ((size_t)offset >= l)
200 					err(1, "snprintf() failed");
201 				q += offset;
202 				l -= offset;
203 			} else
204 				*q++ = *p;
205 
206 		/* Terminate the command string. */
207 		*q = '\0';
208 
209 		/* Run the command. */
210 		if (debug)
211 			(void)printf("%s\n", c);
212 		else
213 			if (exec_shell(c, shell, name))
214 				rval = 1;
215 	}
216 
217 	if (argc != 1)
218 		errx(1, "expecting additional argument%s after \"%s\"",
219 	    (nargs - argc) ? "s" : "", argv[argc - 1]);
220 	free(cmd);
221 	free(c);
222 	free(shell);
223 	exit(rval);
224 }
225 
226 /*
227  * exec_shell --
228  * 	Execute a shell command using passed use_shell and use_name
229  * 	arguments.
230  */
231 static int
232 exec_shell(const char *command, char *use_shell, char *use_name)
233 {
234 	pid_t pid;
235 	int omask, pstat;
236 	sig_t intsave, quitsave;
237 
238 	if (!command)		/* just checking... */
239 		return(1);
240 
241 	omask = sigblock(sigmask(SIGCHLD));
242 	switch(pid = vfork()) {
243 	case -1:			/* error */
244 		err(1, "vfork");
245 	case 0:				/* child */
246 		(void)sigsetmask(omask);
247 		execl(use_shell, use_name, "-c", command, (char *)NULL);
248 		warn("%s", use_shell);
249 		_exit(1);
250 	}
251 	intsave = signal(SIGINT, SIG_IGN);
252 	quitsave = signal(SIGQUIT, SIG_IGN);
253 	pid = waitpid(pid, &pstat, 0);
254 	(void)sigsetmask(omask);
255 	(void)signal(SIGINT, intsave);
256 	(void)signal(SIGQUIT, quitsave);
257 	return(pid == -1 ? -1 : pstat);
258 }
259 
260 void
261 usage(void)
262 {
263 
264 	(void)fprintf(stderr,
265 	"usage: apply [-a magic] [-d] [-0123456789] command arguments ...\n");
266 	exit(1);
267 }
268