1 /*	$OpenBSD: apply.c,v 1.29 2018/04/01 17:45:05 bluhm Exp $	*/
2 /*	$NetBSD: apply.c,v 1.3 1995/03/25 03:38:23 glass Exp $	*/
3 
4 /*-
5  * Copyright (c) 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Jan-Simon Pendry.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/wait.h>
37 
38 #include <ctype.h>
39 #include <err.h>
40 #include <paths.h>
41 #include <signal.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 #define ISMAGICNO(p) \
48 	    (p)[0] == magic && isdigit((unsigned char)(p)[1]) && (p)[1] != '0'
49 
50 __dead	void	usage(void);
51 static	int	mysystem(const char *);
52 
53 char	*str;
54 size_t	 sz;
55 
56 void
stradd(char * p)57 stradd(char *p)
58 {
59 	size_t n;
60 
61 	n = strlen(p);
62 	if (str == NULL) {
63 		sz = (n / 1024 + 1) * 1024;
64 		if ((str = malloc(sz)) == NULL)
65 			err(1, "malloc");
66 		*str = '\0';
67 	} else if (sz - strlen(str) <= n) {
68 		sz += (n / 1024 + 1) * 1024;
69 		if ((str = realloc(str, sz)) == NULL)
70 			err(1, "realloc");
71 	}
72 	strlcat(str, p, sz);
73 }
74 
75 void
strset(char * p)76 strset(char *p)
77 {
78 	if (str != NULL)
79 		str[0] = '\0';
80 	stradd(p);
81 }
82 
83 int
main(int argc,char * argv[])84 main(int argc, char *argv[])
85 {
86 	int ch, debug, i, magic, n, nargs, rval;
87 	char buf[4], *cmd, *p;
88 
89 	if (pledge("stdio proc exec", NULL) == -1)
90 		err(1, "pledge");
91 
92 	debug = 0;
93 	magic = '%';		/* Default magic char is `%'. */
94 	nargs = -1;
95 	while ((ch = getopt(argc, argv, "a:d0123456789")) != -1)
96 		switch (ch) {
97 		case 'a':
98 			if (optarg[0] == '\0' || optarg[1] != '\0')
99 				errx(1,
100 				    "illegal magic character specification.");
101 			magic = optarg[0];
102 			break;
103 		case 'd':
104 			debug = 1;
105 			break;
106 		case '0': case '1': case '2': case '3': case '4':
107 		case '5': case '6': case '7': case '8': case '9':
108 			if (nargs != -1)
109 				errx(1,
110 				    "only one -# argument may be specified.");
111 			nargs = ch - '0';
112 			break;
113 		default:
114 			usage();
115 		}
116 	argc -= optind;
117 	argv += optind;
118 
119 	if (argc < 2)
120 		usage();
121 
122 	/*
123 	 * The command to run is argv[0], and the args are argv[1..].
124 	 * Look for %digit references in the command, remembering the
125 	 * largest one.
126 	 */
127 	for (n = 0, p = argv[0]; *p != '\0'; ++p)
128 		if (ISMAGICNO(p)) {
129 			++p;
130 			if (p[0] - '0' > n)
131 				n = p[0] - '0';
132 		}
133 
134 	/*
135 	 * If there were any %digit references, then use those, otherwise
136 	 * build a new command string with sufficient %digit references at
137 	 * the end to consume (nargs) arguments each time round the loop.
138 	 * Allocate enough space to hold the maximum command.
139 	 */
140 	strset(argv[0]);
141 	if (n == 0) {
142 		/* If nargs not set, default to a single argument. */
143 		if (nargs == -1)
144 			nargs = 1;
145 
146 		for (i = 1; i <= nargs; i++) {
147 			snprintf(buf, sizeof(buf), " %c%d", magic, i);
148 			stradd(buf);
149 		}
150 
151 		/*
152 		 * If nargs set to the special value 0, eat a single
153 		 * argument for each command execution.
154 		 */
155 		if (nargs == 0)
156 			nargs = 1;
157 	} else
158 		nargs = n;
159 	if ((cmd = strdup(str)) == NULL)
160 		err(1, "strdup");
161 
162 	/*
163 	 * (argc) and (argv) are still offset by one to make it simpler to
164 	 * expand %digit references.  At the end of the loop check for (argc)
165 	 * equals 1 means that all the (argv) has been consumed.
166 	 */
167 	for (rval = 0; argc > nargs; argc -= nargs, argv += nargs) {
168 		strset("exec ");
169 
170 		/* Expand command argv references. */
171 		for (p = cmd; *p != '\0'; ++p)
172 			if (ISMAGICNO(p))
173 				stradd(argv[*(++p) - '0']);
174 			else {
175 				strlcpy(buf, p, 2);
176 				stradd(buf);
177 			}
178 
179 		/* Run the command. */
180 		if (debug)
181 			(void)printf("%s\n", str);
182 		else if (mysystem(str))
183 			rval = 1;
184 	}
185 
186 	if (argc != 1)
187 		errx(1, "expecting additional argument%s after \"%s\"",
188 		    (nargs - argc) ? "s" : "", argv[argc - 1]);
189 	exit(rval);
190 }
191 
192 /*
193  * mysystem --
194  * 	Private version of system(3).  Use the user's SHELL environment
195  *	variable as the shell to execute.
196  */
197 static int
mysystem(const char * command)198 mysystem(const char *command)
199 {
200 	static const char *name, *shell;
201 	pid_t pid;
202 	int pstat;
203 	sigset_t mask, omask;
204 	sig_t intsave, quitsave;
205 
206 	if (shell == NULL) {
207 		if ((shell = getenv("SHELL")) == NULL)
208 			shell = _PATH_BSHELL;
209 		if ((name = strrchr(shell, '/')) == NULL)
210 			name = shell;
211 		else
212 			++name;
213 	}
214 	if (!command)		/* just checking... */
215 		return(1);
216 
217 	sigemptyset(&mask);
218 	sigaddset(&mask, SIGCHLD);
219 	sigprocmask(SIG_BLOCK, &mask, &omask);
220 	switch(pid = fork()) {
221 	case -1:			/* error */
222 		err(1, "fork");
223 	case 0:				/* child */
224 		sigprocmask(SIG_SETMASK, &omask, NULL);
225 		execl(shell, name, "-c", command, (char *)NULL);
226 		err(1, "%s", shell);
227 	}
228 	intsave = signal(SIGINT, SIG_IGN);
229 	quitsave = signal(SIGQUIT, SIG_IGN);
230 	pid = waitpid(pid, &pstat, 0);
231 	sigprocmask(SIG_SETMASK, &omask, NULL);
232 	(void)signal(SIGINT, intsave);
233 	(void)signal(SIGQUIT, quitsave);
234 	return(pid == -1 ? -1 : pstat);
235 }
236 
237 __dead void
usage(void)238 usage(void)
239 {
240 	(void)fprintf(stderr,
241 	    "usage: apply [-#] [-d] [-a magic] command argument ...\n");
242 	exit(1);
243 }
244