xref: /netbsd-src/usr.bin/uudecode/uudecode.c (revision 0b9f50897e9a9c6709320fafb4c3787fddcc0a45)
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 1.3 1993/08/27 22:30:54 jtc 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 #include <errno.h>
51 
52 static int decode();
53 static void usage();
54 char *filename;
55 
56 /* ARGSUSED */
57 int
58 main(argc, argv)
59 	int argc;
60 	char **argv;
61 {
62 	int rval;
63 
64 	if (*++argv) {
65 		rval = 0;
66 		do {
67 			if (!freopen(filename = *argv, "r", stdin)) {
68 				(void)fprintf(stderr, "uudecode: %s: %s\n",
69 				    *argv, strerror(errno));
70 				rval = 1;
71 				continue;
72 			}
73 			rval |= decode();
74 		} while (*++argv);
75 	} else {
76 		filename = "stdin";
77 		rval = decode();
78 	}
79 	exit(rval);
80 }
81 
82 static int
83 decode()
84 {
85 	extern int errno;
86 	struct passwd *pw;
87 	register int n;
88 	register char ch, *p;
89 	int mode, n1;
90 	char buf[MAXPATHLEN];
91 
92 	/* search for header line */
93 	do {
94 		if (!fgets(buf, sizeof(buf), stdin)) {
95 			(void)fprintf(stderr,
96 			    "uudecode: %s: no \"begin\" line\n", filename);
97 			return(1);
98 		}
99 	} while (strncmp(buf, "begin ", 6));
100 	(void)sscanf(buf, "begin %o %s", &mode, buf);
101 
102 	/* handle ~user/file format */
103 	if (buf[0] == '~') {
104 		if (!(p = index(buf, '/'))) {
105 			(void)fprintf(stderr, "uudecode: %s: illegal ~user.\n",
106 			    filename);
107 			return(1);
108 		}
109 		*p++ = NULL;
110 		if (!(pw = getpwnam(buf + 1))) {
111 			(void)fprintf(stderr, "uudecode: %s: no user %s.\n",
112 			    filename, buf);
113 			return(1);
114 		}
115 		n = strlen(pw->pw_dir);
116 		n1 = strlen(p);
117 		if (n + n1 + 2 > MAXPATHLEN) {
118 			(void)fprintf(stderr, "uudecode: %s: path too long.\n",
119 			    filename);
120 			return(1);
121 		}
122 		bcopy(p, buf + n + 1, n1 + 1);
123 		bcopy(pw->pw_dir, buf, n);
124 		buf[n] = '/';
125 	}
126 
127 	/* create output file, set mode */
128 	if (!freopen(buf, "w", stdout) ||
129 	    fchmod(fileno(stdout), mode&0666)) {
130 		(void)fprintf(stderr, "uudecode: %s: %s: %s\n", buf,
131 		    filename, strerror(errno));
132 		return(1);
133 	}
134 
135 	/* for each input line */
136 	for (;;) {
137 		if (!fgets(p = buf, sizeof(buf), stdin)) {
138 			(void)fprintf(stderr, "uudecode: %s: short file.\n",
139 			    filename);
140 			return(1);
141 		}
142 #define	DEC(c)	(((c) - ' ') & 077)		/* single character decode */
143 		/*
144 		 * `n' is used to avoid writing out all the characters
145 		 * at the end of the file.
146 		 */
147 		if ((n = DEC(*p)) <= 0)
148 			break;
149 		for (++p; n > 0; p += 4, n -= 3)
150 			if (n >= 3) {
151 				ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
152 				putchar(ch);
153 				ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
154 				putchar(ch);
155 				ch = DEC(p[2]) << 6 | DEC(p[3]);
156 				putchar(ch);
157 			}
158 			else {
159 				if (n >= 1) {
160 					ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
161 					putchar(ch);
162 				}
163 				if (n >= 2) {
164 					ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
165 					putchar(ch);
166 				}
167 				if (n >= 3) {
168 					ch = DEC(p[2]) << 6 | DEC(p[3]);
169 					putchar(ch);
170 				}
171 			}
172 	}
173 	if (!fgets(buf, sizeof(buf), stdin) || strcmp(buf, "end\n")) {
174 		(void)fprintf(stderr, "uudecode: %s: no \"end\" line.\n",
175 		    filename);
176 		return(1);
177 	}
178 	return(0);
179 }
180 
181 static void
182 usage()
183 {
184 	(void)fprintf(stderr, "usage: uudecode [file ...]\n");
185 	exit(1);
186 }
187