summaryrefslogtreecommitdiff
path: root/usr.bin/apply/apply.c
blob: 6218c6cb5d6c87c3a6b581f267d180ed8e7c3e58 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
/*	$OpenBSD: apply.c,v 1.26 2013/11/25 18:03:17 deraadt Exp $	*/
/*	$NetBSD: apply.c,v 1.3 1995/03/25 03:38:23 glass Exp $	*/

/*-
 * Copyright (c) 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Jan-Simon Pendry.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/wait.h>

#include <ctype.h>
#include <err.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

__dead	void	usage(void);
static	int	mysystem(const char *);

int
main(int argc, char *argv[])
{
	int ch, clen, debug, i, l, magic, n, nargs, rval;
	char *c, *c2, *cmd, *p, *q;
	size_t len;

	debug = 0;
	magic = '%';		/* Default magic char is `%'. */
	nargs = -1;
	while ((ch = getopt(argc, argv, "a:d0123456789")) != -1)
		switch (ch) {
		case 'a':
			if (optarg[1] != '\0')
				errx(1,
				    "illegal magic character specification.");
			magic = optarg[0];
			break;
		case 'd':
			debug = 1;
			break;
		case '0': case '1': case '2': case '3': case '4':
		case '5': case '6': case '7': case '8': case '9':
			if (nargs != -1)
				errx(1,
				    "only one -# argument may be specified.");
			nargs = ch - '0';
			break;
		default:
			usage();
		}
	argc -= optind;
	argv += optind;

	if (argc < 2)
		usage();

	/*
	 * The command to run is argv[0], and the args are argv[1..].
	 * Look for %digit references in the command, remembering the
	 * largest one.
	 */
	for (n = 0, p = argv[0]; *p != '\0'; ++p)
		if (p[0] == magic &&
		    isdigit((unsigned char)p[1]) && p[1] != '0') {
			++p;
			if (p[0] - '0' > n)
				n = p[0] - '0';
		}

	/*
	 * If there were any %digit references, then use those, otherwise
	 * build a new command string with sufficient %digit references at
	 * the end to consume (nargs) arguments each time round the loop.
	 * Allocate enough space to hold the maximum command.
	 */
	if (n == 0) {
		len = sizeof("exec ") - 1 +
		    strlen(argv[0]) + 9 * (sizeof(" %1") - 1) + 1;
		if ((cmd = malloc(len)) == NULL)
			err(1, NULL);

		/* If nargs not set, default to a single argument. */
		if (nargs == -1)
			nargs = 1;

		l = snprintf(cmd, len, "exec %s", argv[0]);
		if (l >= len || l == -1)
			errx(1, "error building exec string");
		len -= l;
		p = cmd + l;
		
		for (i = 1; i <= nargs; i++) {
			l = snprintf(p, len, " %c%d", magic, i);
			if (l >= len || l == -1)
				errx(1, "error numbering arguments");
			len -= l;
			p += l;
		}

		/*
		 * If nargs set to the special value 0, eat a single
		 * argument for each command execution.
		 */
		if (nargs == 0)
			nargs = 1;
	} else {
		if (asprintf(&cmd, "exec %s", argv[0]) == -1)
			err(1, NULL);		
		nargs = n;
	}

	/*
	 * Grab some space in which to build the command.  Allocate
	 * as necessary later, but no reason to build it up slowly
	 * for the normal case.
	 */
	if ((c = malloc(clen = 1024)) == NULL)
		err(1, NULL);

	/*
	 * (argc) and (argv) are still offset by one to make it simpler to
	 * expand %digit references.  At the end of the loop check for (argc)
	 * equals 1 means that all the (argv) has been consumed.
	 */
	for (rval = 0; argc > nargs; argc -= nargs, argv += nargs) {
		/*
		 * Find a max value for the command length, and ensure
		 * there's enough space to build it.
		 */
		for (l = strlen(cmd), i = 0; i < nargs; i++)
			l += strlen(argv[i+1]);
		if (l > clen) {
			if ((c2 = realloc(c, l)) == NULL)
				err(1, NULL);
			c = c2;
			clen = l;
		}

		/* Expand command argv references. */
		for (p = cmd, q = c; *p != '\0'; ++p)
			if (p[0] == magic &&
			    isdigit((unsigned char)p[1]) && p[1] != '0') {
				strlcpy(q, argv[(++p)[0] - '0'], c + clen - q);
				q += strlen(q);
			} else
				*q++ = *p;

		/* Terminate the command string. */
		*q = '\0';

		/* Run the command. */
		if (debug)
			(void)printf("%s\n", c);
		else if (mysystem(c))
			rval = 1;
	}

	if (argc != 1)
		errx(1, "expecting additional argument%s after \"%s\"",
		    (nargs - argc) ? "s" : "", argv[argc - 1]);
	exit(rval);
}

/*
 * mysystem --
 * 	Private version of system(3).  Use the user's SHELL environment
 *	variable as the shell to execute.
 */
static int
mysystem(const char *command)
{
	static const char *name, *shell;
	pid_t pid;
	int pstat;
	sigset_t mask, omask;
	sig_t intsave, quitsave;

	if (shell == NULL) {
		if ((shell = getenv("SHELL")) == NULL)
			shell = _PATH_BSHELL;
		if ((name = strrchr(shell, '/')) == NULL)
			name = shell;
		else
			++name;
	}
	if (!command)		/* just checking... */
		return(1);

	sigemptyset(&mask);
	sigaddset(&mask, SIGCHLD);
	sigprocmask(SIG_BLOCK, &mask, &omask);
	switch(pid = fork()) {
	case -1:			/* error */
		err(1, "fork");
	case 0:				/* child */
		sigprocmask(SIG_SETMASK, &omask, NULL);
		execl(shell, name, "-c", command, (char *)NULL);
		err(1, "%s", shell);
	}
	intsave = signal(SIGINT, SIG_IGN);
	quitsave = signal(SIGQUIT, SIG_IGN);
	pid = waitpid(pid, &pstat, 0);
	sigprocmask(SIG_SETMASK, &omask, NULL);
	(void)signal(SIGINT, intsave);
	(void)signal(SIGQUIT, quitsave);
	return(pid == -1 ? -1 : pstat);
}

__dead void
usage(void)
{
	(void)fprintf(stderr,
	    "usage: apply [-#] [-d] [-a magic] command argument ...\n");
	exit(1);
}