xref: /netbsd-src/usr.bin/uudecode/uudecode.c (revision e9d867ef5010fbab8d48045c13025636f5cd7479)
1 /*
2  * Copyright (c) 1983 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 /*static char sccsid[] = "from: @(#)uudecode.c	5.10 (Berkeley) 6/1/90";*/
36 static char rcsid[] = "$Id: uudecode.c,v 1.2 1993/08/01 18:03:42 mycroft Exp $";
37 #endif /* not lint */
38 
39 /*
40  * uudecode [file ...]
41  *
42  * create the specified file, decoding as you go.
43  * used with uuencode.
44  */
45 #include <sys/param.h>
46 #include <sys/stat.h>
47 #include <pwd.h>
48 #include <stdio.h>
49 #include <string.h>
50 
51 char *filename;
52 
53 /* ARGSUSED */
54 main(argc, argv)
55 	int argc;
56 	char **argv;
57 {
58 	extern int errno;
59 	int rval;
60 
61 	if (*++argv) {
62 		rval = 0;
63 		do {
64 			if (!freopen(filename = *argv, "r", stdin)) {
65 				(void)fprintf(stderr, "uudecode: %s: %s\n",
66 				    *argv, strerror(errno));
67 				rval = 1;
68 				continue;
69 			}
70 			rval |= decode();
71 		} while (*++argv);
72 	} else {
73 		filename = "stdin";
74 		rval = decode();
75 	}
76 	exit(rval);
77 }
78 
79 decode()
80 {
81 	extern int errno;
82 	struct passwd *pw;
83 	register int n;
84 	register char ch, *p;
85 	int mode, n1;
86 	char buf[MAXPATHLEN];
87 
88 	/* search for header line */
89 	do {
90 		if (!fgets(buf, sizeof(buf), stdin)) {
91 			(void)fprintf(stderr,
92 			    "uudecode: %s: no \"begin\" line\n", filename);
93 			return(1);
94 		}
95 	} while (strncmp(buf, "begin ", 6));
96 	(void)sscanf(buf, "begin %o %s", &mode, buf);
97 
98 	/* handle ~user/file format */
99 	if (buf[0] == '~') {
100 		if (!(p = index(buf, '/'))) {
101 			(void)fprintf(stderr, "uudecode: %s: illegal ~user.\n",
102 			    filename);
103 			return(1);
104 		}
105 		*p++ = NULL;
106 		if (!(pw = getpwnam(buf + 1))) {
107 			(void)fprintf(stderr, "uudecode: %s: no user %s.\n",
108 			    filename, buf);
109 			return(1);
110 		}
111 		n = strlen(pw->pw_dir);
112 		n1 = strlen(p);
113 		if (n + n1 + 2 > MAXPATHLEN) {
114 			(void)fprintf(stderr, "uudecode: %s: path too long.\n",
115 			    filename);
116 			return(1);
117 		}
118 		bcopy(p, buf + n + 1, n1 + 1);
119 		bcopy(pw->pw_dir, buf, n);
120 		buf[n] = '/';
121 	}
122 
123 	/* create output file, set mode */
124 	if (!freopen(buf, "w", stdout) ||
125 	    fchmod(fileno(stdout), mode&0666)) {
126 		(void)fprintf(stderr, "uudecode: %s: %s: %s\n", buf,
127 		    filename, strerror(errno));
128 		return(1);
129 	}
130 
131 	/* for each input line */
132 	for (;;) {
133 		if (!fgets(p = buf, sizeof(buf), stdin)) {
134 			(void)fprintf(stderr, "uudecode: %s: short file.\n",
135 			    filename);
136 			return(1);
137 		}
138 #define	DEC(c)	(((c) - ' ') & 077)		/* single character decode */
139 		/*
140 		 * `n' is used to avoid writing out all the characters
141 		 * at the end of the file.
142 		 */
143 		if ((n = DEC(*p)) <= 0)
144 			break;
145 		for (++p; n > 0; p += 4, n -= 3)
146 			if (n >= 3) {
147 				ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
148 				putchar(ch);
149 				ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
150 				putchar(ch);
151 				ch = DEC(p[2]) << 6 | DEC(p[3]);
152 				putchar(ch);
153 			}
154 			else {
155 				if (n >= 1) {
156 					ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
157 					putchar(ch);
158 				}
159 				if (n >= 2) {
160 					ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
161 					putchar(ch);
162 				}
163 				if (n >= 3) {
164 					ch = DEC(p[2]) << 6 | DEC(p[3]);
165 					putchar(ch);
166 				}
167 			}
168 	}
169 	if (!fgets(buf, sizeof(buf), stdin) || strcmp(buf, "end\n")) {
170 		(void)fprintf(stderr, "uudecode: %s: no \"end\" line.\n",
171 		    filename);
172 		return(1);
173 	}
174 	return(0);
175 }
176 
177 usage()
178 {
179 	(void)fprintf(stderr, "usage: uudecode [file ...]\n");
180 	exit(1);
181 }
182