xref: /dragonfly/usr.bin/apply/apply.c (revision 1de703da)
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  * @(#)apply.c	8.4 (Berkeley) 4/4/94
37  * $FreeBSD: src/usr.bin/apply/apply.c,v 1.8.2.3 2001/08/01 23:28:04 obrien Exp $
38  * $DragonFly: src/usr.bin/apply/apply.c,v 1.2 2003/06/17 04:29:25 dillon Exp $
39  */
40 
41 #include <sys/types.h>
42 
43 #include <sys/wait.h>
44 
45 #include <ctype.h>
46 #include <err.h>
47 #include <paths.h>
48 #include <signal.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <unistd.h>
53 
54 #define EXEC	"exec "
55 
56 static int	exec_shell(const char *, char *, char *);
57 static void	usage(void);
58 
59 int
60 main(int argc, char *argv[]) {
61 	int ch, debug, i, magic, n, nargs, offset, rval;
62 	size_t clen, cmdsize, l;
63 	char *c, *cmd, *name, *p, *q, *shell, *slashp, *tmpshell;
64 
65 	debug = 0;
66 	magic = '%';		/* Default magic char is `%'. */
67 	nargs = -1;
68 	while ((ch = getopt(argc, argv, "a:d0123456789")) != -1)
69 		switch (ch) {
70 		case 'a':
71 			if (optarg[1] != '\0')
72 				errx(1,
73 				    "illegal magic character specification");
74 			magic = optarg[0];
75 			break;
76 		case 'd':
77 			debug = 1;
78 			break;
79 		case '0': case '1': case '2': case '3': case '4':
80 		case '5': case '6': case '7': case '8': case '9':
81 			if (nargs != -1)
82 				errx(1,
83 				    "only one -# argument may be specified");
84 			nargs = optopt - '0';
85 			break;
86 		default:
87 			usage();
88 		}
89 	argc -= optind;
90 	argv += optind;
91 
92 	if (argc < 2)
93 		usage();
94 
95 	/*
96 	 * The command to run is argv[0], and the args are argv[1..].
97 	 * Look for %digit references in the command, remembering the
98 	 * largest one.
99 	 */
100 	for (n = 0, p = argv[0]; *p != '\0'; ++p)
101 		if (p[0] == magic && isdigit(p[1]) && p[1] != '0') {
102 			++p;
103 			if (p[0] - '0' > n)
104 				n = p[0] - '0';
105 		}
106 
107 	/*
108 	 * Figure out the shell and name arguments to pass to execl()
109 	 * in exec_shell().  Always malloc() shell and just set name
110 	 * to point at the last part of shell if there are any backslashes,
111 	 * otherwise just set it to point at the space malloc()'d.  If
112 	 * SHELL environment variable exists, replace contents of
113 	 * shell with it.
114 	 */
115 	shell = name = NULL;
116 	tmpshell = getenv("SHELL");
117 	shell = (tmpshell != NULL) ? strdup(tmpshell) : strdup(_PATH_BSHELL);
118 	if (shell == NULL)
119 		err(1, "strdup() failed");
120 	slashp = strrchr(shell, '/');
121 	name = (slashp != NULL) ? slashp + 1 : shell;
122 
123 	/*
124 	 * If there were any %digit references, then use those, otherwise
125 	 * build a new command string with sufficient %digit references at
126 	 * the end to consume (nargs) arguments each time round the loop.
127 	 * Allocate enough space to hold the maximum command.  Save the
128 	 * size to pass to snprintf().
129 	 */
130 	cmdsize = sizeof(EXEC) - 1 + strlen(argv[0])
131 	    + 9 * (sizeof(" %1") - 1) + 1;
132 	if ((cmd = malloc(cmdsize)) == NULL)
133 		err(1, NULL);
134 
135 	if (n == 0) {
136 		/* If nargs not set, default to a single argument. */
137 		if (nargs == -1)
138 			nargs = 1;
139 
140 		p = cmd;
141 		offset = snprintf(cmd, cmdsize, EXEC "%s", argv[0]);
142 		if ((size_t)offset >= cmdsize)
143 			err(1, "snprintf() failed");
144 		p += offset;
145 		cmdsize -= offset;
146 		for (i = 1; i <= nargs; i++) {
147 			offset = snprintf(p, cmdsize, " %c%d", magic, i);
148 			if ((size_t)offset >= cmdsize)
149 				err(1, "snprintf() failed");
150 			p += offset;
151 			cmdsize -= offset;
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 		offset = snprintf(cmd, cmdsize, EXEC "%s", argv[0]);
162 		if ((size_t)offset >= cmdsize)
163 			err(1, "snprintf() failed");
164 		nargs = n;
165 	}
166 
167 	/*
168 	 * Grab some space in which to build the command.  Allocate
169 	 * as necessary later, but no reason to build it up slowly
170 	 * for the normal case.
171 	 */
172 	if ((c = malloc(clen = 1024)) == NULL)
173 		err(1, NULL);
174 
175 	/*
176 	 * (argc) and (argv) are still offset by one to make it simpler to
177 	 * expand %digit references.  At the end of the loop check for (argc)
178 	 * equals 1 means that all the (argv) has been consumed.
179 	 */
180 	for (rval = 0; argc > nargs; argc -= nargs, argv += nargs) {
181 		/*
182 		 * Find a max value for the command length, and ensure
183 		 * there's enough space to build it.
184 		 */
185 		for (l = strlen(cmd), i = 0; i < nargs; i++)
186 			l += strlen(argv[i+1]);
187 		if (l > clen && (c = realloc(c, clen = l)) == NULL)
188 			err(1, NULL);
189 
190 		/* Expand command argv references. */
191 		for (p = cmd, q = c; *p != '\0'; ++p)
192 			if (p[0] == magic && isdigit(p[1]) && p[1] != '0') {
193 				offset = snprintf(q, l, "%s",
194 				    argv[(++p)[0] - '0']);
195 				if ((size_t)offset >= l)
196 					err(1, "snprintf() failed");
197 				q += offset;
198 				l -= offset;
199 			} else
200 				*q++ = *p;
201 
202 		/* Terminate the command string. */
203 		*q = '\0';
204 
205 		/* Run the command. */
206 		if (debug)
207 			(void)printf("%s\n", c);
208 		else
209 			if (exec_shell(c, shell, name))
210 				rval = 1;
211 	}
212 
213 	if (argc != 1)
214 		errx(1, "expecting additional argument%s after \"%s\"",
215 	    (nargs - argc) ? "s" : "", argv[argc - 1]);
216 	free(cmd);
217 	free(c);
218 	free(shell);
219 	exit(rval);
220 }
221 
222 /*
223  * exec_shell --
224  * 	Execute a shell command using passed use_shell and use_name
225  * 	arguments.
226  */
227 static int
228 exec_shell(const char *command, char *use_shell, char *use_name)
229 {
230 	pid_t pid;
231 	int omask, pstat;
232 	sig_t intsave, quitsave;
233 
234 	if (!command)		/* just checking... */
235 		return(1);
236 
237 	omask = sigblock(sigmask(SIGCHLD));
238 	switch(pid = vfork()) {
239 	case -1:			/* error */
240 		err(1, "vfork");
241 	case 0:				/* child */
242 		(void)sigsetmask(omask);
243 		execl(use_shell, use_name, "-c", command, (char *)NULL);
244 		warn("%s", use_shell);
245 		_exit(1);
246 	}
247 	intsave = signal(SIGINT, SIG_IGN);
248 	quitsave = signal(SIGQUIT, SIG_IGN);
249 	pid = waitpid(pid, &pstat, 0);
250 	(void)sigsetmask(omask);
251 	(void)signal(SIGINT, intsave);
252 	(void)signal(SIGQUIT, quitsave);
253 	return(pid == -1 ? -1 : pstat);
254 }
255 
256 void
257 usage()
258 {
259 
260 	(void)fprintf(stderr,
261 	"usage: apply [-a magic] [-d] [-0123456789] command arguments ...\n");
262 	exit(1);
263 }
264