1/*	$NetBSD: apply.c,v 1.19 2016/03/12 22:28:04 dholland Exp $	*/
2
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#include <sys/cdefs.h>
36#ifndef lint
37#if 0
38static char sccsid[] = "@(#)apply.c	8.4 (Berkeley) 4/4/94";
39#else
40__RCSID("$NetBSD: apply.c,v 1.19 2016/03/12 22:28:04 dholland Exp $");
41#endif
42#endif /* not lint */
43
44#include <sys/wait.h>
45
46#include <ctype.h>
47#include <err.h>
48#include <paths.h>
49#include <signal.h>
50#include <stdio.h>
51#include <stdlib.h>
52#include <string.h>
53#include <unistd.h>
54
55static __dead void usage(void);
56static int shell_system(const char *);
57
58int
59main(int argc, char *argv[])
60{
61	size_t clen, l;
62	int ch, debug, i, magic, n, nargs, rval;
63	char *c, *cmd, *p, *q, *nc;
64
65	(void)setprogname(argv[0]);	/* for portability */
66
67	/* Option defaults */
68	debug = 0;
69	magic = '%';
70	nargs = -1;
71
72	while ((ch = getopt(argc, argv, "a:d0123456789")) != -1) {
73		switch (ch) {
74		case 'a':
75			if (optarg[1] != '\0')
76				errx(EXIT_FAILURE,
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(EXIT_FAILURE,
87				    "Only one -# argument may be specified.");
88			nargs = optopt - '0';
89			break;
90		default:
91			usage();
92		}
93	}
94	argc -= optind;
95	argv += optind;
96
97	if (argc < 2)
98		usage();
99
100	/*
101	 * The command to run is now argv[0], and the args are argv[1+].
102	 * Look for %digit references in the command, remembering the
103	 * largest one.
104	 */
105	n = 0;
106	for (p = argv[0]; p[0] != '\0'; ++p) {
107		if (p[0] == magic && p[1] != '\0' &&
108		    isdigit((unsigned char)p[1]) && p[1] != '0') {
109			++p;
110			if (p[0] - '0' > n)
111				n = p[0] - '0';
112		}
113	}
114
115	/*
116	 * If there were any %digit references, then use those, otherwise
117	 * build a new command string with sufficient %digit references at
118	 * the end to consume (nargs) arguments each time round the loop.
119	 * Allocate enough space to hold the maximum command.
120	 */
121	if ((cmd = malloc(sizeof("exec ") - 1 +
122	    strlen(argv[0]) + 9 * (sizeof(" %1") - 1) + 1)) == NULL)
123		err(EXIT_FAILURE, "malloc");
124
125	if (n == 0) {
126		/* If nargs not set, default to a single argument. */
127		if (nargs == -1)
128			nargs = 1;
129
130		p = cmd;
131		p += sprintf(cmd, "exec %s", argv[0]);
132		for (i = 1; i <= nargs; i++)
133			p += sprintf(p, " %c%d", magic, i);
134
135		/*
136		 * If nargs set to the special value 0, eat a single
137		 * argument for each command execution.
138		 */
139		if (nargs == 0)
140			nargs = 1;
141	} else {
142		(void)sprintf(cmd, "exec %s", argv[0]);
143		nargs = n;
144	}
145
146	/*
147	 * Grab some space in which to build the command.  Allocate
148	 * as necessary later, but no reason to build it up slowly
149	 * for the normal case.
150	 */
151	if ((c = malloc(clen = 1024)) == NULL)
152		err(EXIT_FAILURE, "malloc");
153
154	/*
155	 * (argc) and (argv) are still offset by one to make it simpler to
156	 * expand %digit references.  At the end of the loop check for (argc)
157	 * equals 1 means that all the (argv) has been consumed.
158	 */
159	for (rval = 0; argc > nargs; argc -= nargs, argv += nargs) {
160		/*
161		 * Find a max value for the command length, and ensure
162		 * there's enough space to build it.
163		 */
164		for (l = strlen(cmd), i = 0; i < nargs; i++)
165			l += strlen(argv[i+1]);
166		if (l > clen) {
167			nc = realloc(c, l);
168			if (nc == NULL)
169				err(EXIT_FAILURE, "malloc");
170			c = nc;
171			clen = l;
172		}
173
174		/* Expand command argv references. */
175		for (p = cmd, q = c; *p != '\0'; ++p) {
176			if (p[0] == magic && isdigit((unsigned char)p[1]) &&
177			    p[1] != '0')
178				q += sprintf(q, "%s", argv[(++p)[0] - '0']);
179			else
180				*q++ = *p;
181		}
182
183		/* Terminate the command string. */
184		*q = '\0';
185
186		/* Run the command. */
187		if (debug)
188			(void)printf("%s\n", c);
189		else if (shell_system(c))
190			rval = 1;
191	}
192
193	if (argc != 1)
194		errx(EXIT_FAILURE,
195		    "Expecting additional argument%s after \"%s\"",
196		    (nargs - argc) ? "s" : "", argv[argc - 1]);
197	return rval;
198}
199
200/*
201 * shell_system --
202 * 	Private version of system(3).  Use the user's SHELL environment
203 *	variable as the shell to execute.
204 */
205static int
206shell_system(const char *command)
207{
208	static const char *name, *shell;
209	int status;
210	int omask;
211	pid_t pid;
212	sig_t intsave, quitsave;
213
214	if (shell == NULL) {
215		if ((shell = getenv("SHELL")) == NULL)
216			shell = _PATH_BSHELL;
217		if ((name = strrchr(shell, '/')) == NULL)
218			name = shell;
219		else
220			++name;
221	}
222
223	if (!command) {
224		/* just checking... */
225		return(1);
226	}
227
228	omask = sigblock(sigmask(SIGCHLD));
229	switch (pid = vfork()) {
230	case -1:
231		/* error */
232		err(EXIT_FAILURE, "vfork");
233		/*NOTREACHED*/
234	case 0:
235		/* child */
236		(void)sigsetmask(omask);
237		(void)execl(shell, name, "-c", command, (char *)NULL);
238		warn("%s", shell);
239		_exit(1);
240		/*NOTREACHED*/
241	default:
242		/* parent */
243		intsave = signal(SIGINT, SIG_IGN);
244		quitsave = signal(SIGQUIT, SIG_IGN);
245		pid = waitpid(pid, &status, 0);
246		(void)sigsetmask(omask);
247		(void)signal(SIGINT, intsave);
248		(void)signal(SIGQUIT, quitsave);
249		return pid == -1 ? -1 : status;
250	}
251	/*NOTREACHED*/
252}
253
254static __dead void
255usage(void)
256{
257
258	(void)fprintf(stderr,
259	    "usage: %s [-a magic] [-0123456789] command arguments ...\n",
260	    getprogname());
261	exit(1);
262}
263