xref: /original-bsd/usr.bin/apply/apply.c (revision e58c8952)
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  * %sccs.include.redist.c%
9  */
10 
11 #ifndef lint
12 static char sccsid[] = "@(#)apply.c	8.4 (Berkeley) 04/04/94";
13 #endif /* not lint */
14 
15 #include <sys/wait.h>
16 
17 #include <ctype.h>
18 #include <err.h>
19 #include <paths.h>
20 #include <signal.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <unistd.h>
25 
26 void	usage __P((void));
27 int	system __P((const char *));
28 
29 int
30 main(argc, argv)
31 	int argc;
32 	char *argv[];
33 {
34 	int ch, clen, debug, i, l, magic, n, nargs, rval;
35 	char *c, *cmd, *p, *q;
36 
37 	debug = 0;
38 	magic = '%';		/* Default magic char is `%'. */
39 	nargs = -1;
40 	while ((ch = getopt(argc, argv, "a:d0123456789")) != EOF)
41 		switch (ch) {
42 		case 'a':
43 			if (optarg[1] != '\0')
44 				errx(1,
45 				    "illegal magic character specification.");
46 			magic = optarg[0];
47 			break;
48 		case 'd':
49 			debug = 1;
50 			break;
51 		case '0': case '1': case '2': case '3': case '4':
52 		case '5': case '6': case '7': case '8': case '9':
53 			if (nargs != -1)
54 				errx(1,
55 				    "only one -# argument may be specified.");
56 			nargs = optopt - '0';
57 			break;
58 		default:
59 			usage();
60 		}
61 	argc -= optind;
62 	argv += optind;
63 
64 	if (argc < 2)
65 		usage();
66 
67 	/*
68 	 * The command to run is argv[0], and the args are argv[1..].
69 	 * Look for %digit references in the command, remembering the
70 	 * largest one.
71 	 */
72 	for (n = 0, p = argv[0]; *p != '\0'; ++p)
73 		if (p[0] == magic && isdigit(p[1]) && p[1] != '0') {
74 			++p;
75 			if (p[0] - '0' > n)
76 				n = p[0] - '0';
77 		}
78 
79 	/*
80 	 * If there were any %digit references, then use those, otherwise
81 	 * build a new command string with sufficient %digit references at
82 	 * the end to consume (nargs) arguments each time round the loop.
83 	 * Allocate enough space to hold the maximum command.
84 	 */
85 	if ((cmd = malloc(sizeof("exec ") - 1 +
86 	    strlen(argv[0]) + 9 * (sizeof(" %1") - 1) + 1)) == NULL)
87 		err(1, NULL);
88 
89 	if (n == 0) {
90 		/* If nargs not set, default to a single argument. */
91 		if (nargs == -1)
92 			nargs = 1;
93 
94 		p = cmd;
95 		p += sprintf(cmd, "exec %s", argv[0]);
96 		for (i = 1; i <= nargs; i++)
97 			p += sprintf(p, " %c%d", magic, i);
98 
99 		/*
100 		 * If nargs set to the special value 0, eat a single
101 		 * argument for each command execution.
102 		 */
103 		if (nargs == 0)
104 			nargs = 1;
105 	} else {
106 		(void)sprintf(cmd, "exec %s", argv[0]);
107 		nargs = n;
108 	}
109 
110 	/*
111 	 * Grab some space in which to build the command.  Allocate
112 	 * as necessary later, but no reason to build it up slowly
113 	 * for the normal case.
114 	 */
115 	if ((c = malloc(clen = 1024)) == NULL)
116 		err(1, NULL);
117 
118 	/*
119 	 * (argc) and (argv) are still offset by one to make it simpler to
120 	 * expand %digit references.  At the end of the loop check for (argc)
121 	 * equals 1 means that all the (argv) has been consumed.
122 	 */
123 	for (rval = 0; argc > nargs; argc -= nargs, argv += nargs) {
124 		/*
125 		 * Find a max value for the command length, and ensure
126 		 * there's enough space to build it.
127 		 */
128 		for (l = strlen(cmd), i = 0; i < nargs; i++)
129 			l += strlen(argv[i]);
130 		if (l > clen && (c = realloc(c, clen = l)) == NULL)
131 			err(1, NULL);
132 
133 		/* Expand command argv references. */
134 		for (p = cmd, q = c; *p != '\0'; ++p)
135 			if (p[0] == magic && isdigit(p[1]) && p[1] != '0')
136 				q += sprintf(q, "%s", argv[(++p)[0] - '0']);
137 			else
138 				*q++ = *p;
139 
140 		/* Terminate the command string. */
141 		*q = '\0';
142 
143 		/* Run the command. */
144 		if (debug)
145 			(void)printf("%s\n", c);
146 		else
147 			if (system(c))
148 				rval = 1;
149 	}
150 
151 	if (argc != 1)
152 		errx(1, "expecting additional argument%s after \"%s\"",
153 		    (nargs - argc) ? "s" : "", argv[argc - 1]);
154 	exit(rval);
155 }
156 
157 /*
158  * system --
159  * 	Private version of system(3).  Use the user's SHELL environment
160  *	variable as the shell to execute.
161  */
162 int
163 system(command)
164 	const char *command;
165 {
166 	static char *name, *shell;
167 	union wait pstat;
168 	pid_t pid;
169 	int omask;
170 	sig_t intsave, quitsave;
171 
172 	if (shell == NULL) {
173 		if ((shell = getenv("SHELL")) == NULL)
174 			shell = _PATH_BSHELL;
175 		if ((name = strrchr(shell, '/')) == NULL)
176 			name = shell;
177 		else
178 			++name;
179 	}
180 	if (!command)		/* just checking... */
181 		return(1);
182 
183 	omask = sigblock(sigmask(SIGCHLD));
184 	switch(pid = vfork()) {
185 	case -1:			/* error */
186 		err(1, "fork");
187 	case 0:				/* child */
188 		(void)sigsetmask(omask);
189 		execl(shell, name, "-c", command, NULL);
190 		err(1, "%s", shell);
191 	}
192 	intsave = signal(SIGINT, SIG_IGN);
193 	quitsave = signal(SIGQUIT, SIG_IGN);
194 	pid = waitpid(pid, (int *)&pstat, 0);
195 	(void)sigsetmask(omask);
196 	(void)signal(SIGINT, intsave);
197 	(void)signal(SIGQUIT, quitsave);
198 	return(pid == -1 ? -1 : pstat.w_status);
199 }
200 
201 void
202 usage()
203 {
204 
205 	(void)fprintf(stderr,
206 	    "usage: apply [-a magic] [-0123456789] command arguments ...\n");
207 	exit(1);
208 }
209