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path: root/coreutils/uudecode.c (plain)
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1/* vi: set sw=4 ts=4: */
2/*
3 * Copyright 2003, Glenn McGrath
4 *
5 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
6 *
7 * Based on specification from
8 * http://www.opengroup.org/onlinepubs/007904975/utilities/uuencode.html
9 *
10 * Bugs: the spec doesn't mention anything about "`\n`\n" prior to the
11 * "end" line
12 */
13//config:config UUDECODE
14//config: bool "uudecode"
15//config: default y
16//config: help
17//config: uudecode is used to decode a uuencoded file.
18
19//applet:IF_UUDECODE(APPLET(uudecode, BB_DIR_USR_BIN, BB_SUID_DROP))
20
21//kbuild:lib-$(CONFIG_UUDECODE) += uudecode.o
22
23//usage:#define uudecode_trivial_usage
24//usage: "[-o OUTFILE] [INFILE]"
25//usage:#define uudecode_full_usage "\n\n"
26//usage: "Uudecode a file\n"
27//usage: "Finds OUTFILE in uuencoded source unless -o is given"
28//usage:
29//usage:#define uudecode_example_usage
30//usage: "$ uudecode -o busybox busybox.uu\n"
31//usage: "$ ls -l busybox\n"
32//usage: "-rwxr-xr-x 1 ams ams 245264 Jun 7 21:35 busybox\n"
33
34#include "libbb.h"
35
36#if ENABLE_UUDECODE
37static void FAST_FUNC read_stduu(FILE *src_stream, FILE *dst_stream, int flags UNUSED_PARAM)
38{
39 char *line;
40
41 for (;;) {
42 int encoded_len, str_len;
43 char *line_ptr, *dst;
44 size_t line_len;
45
46 line_len = 64 * 1024;
47 line = xmalloc_fgets_str_len(src_stream, "\n", &line_len);
48 if (!line)
49 break;
50 /* Handle both Unix and MSDOS text, and stray trailing spaces */
51 str_len = line_len;
52 while (--str_len >= 0 && isspace(line[str_len]))
53 line[str_len] = '\0';
54
55 if (strcmp(line, "end") == 0) {
56 return; /* the only non-error exit */
57 }
58
59 line_ptr = line;
60 while (*line_ptr) {
61 *line_ptr = (*line_ptr - 0x20) & 0x3f;
62 line_ptr++;
63 }
64 str_len = line_ptr - line;
65
66 encoded_len = line[0] * 4 / 3;
67 /* Check that line is not too short. (we tolerate
68 * overly _long_ line to accommodate possible extra '`').
69 * Empty line case is also caught here. */
70 if (str_len <= encoded_len) {
71 break; /* go to bb_error_msg_and_die("short file"); */
72 }
73 if (encoded_len <= 0) {
74 /* Ignore the "`\n" line, why is it even in the encode file ? */
75 free(line);
76 continue;
77 }
78 if (encoded_len > 60) {
79 bb_error_msg_and_die("line too long");
80 }
81
82 dst = line;
83 line_ptr = line + 1;
84 do {
85 /* Merge four 6 bit chars to three 8 bit chars */
86 *dst++ = line_ptr[0] << 2 | line_ptr[1] >> 4;
87 encoded_len--;
88 if (encoded_len == 0) {
89 break;
90 }
91
92 *dst++ = line_ptr[1] << 4 | line_ptr[2] >> 2;
93 encoded_len--;
94 if (encoded_len == 0) {
95 break;
96 }
97
98 *dst++ = line_ptr[2] << 6 | line_ptr[3];
99 line_ptr += 4;
100 encoded_len -= 2;
101 } while (encoded_len > 0);
102 fwrite(line, 1, dst - line, dst_stream);
103 free(line);
104 }
105 bb_error_msg_and_die("short file");
106}
107#endif
108
109#if ENABLE_UUDECODE
110int uudecode_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
111int uudecode_main(int argc UNUSED_PARAM, char **argv)
112{
113 FILE *src_stream;
114 char *outname = NULL;
115 char *line;
116
117 opt_complementary = "?1"; /* 1 argument max */
118 getopt32(argv, "o:", &outname);
119 argv += optind;
120
121 if (!argv[0])
122 *--argv = (char*)"-";
123 src_stream = xfopen_stdin(argv[0]);
124
125 /* Search for the start of the encoding */
126 while ((line = xmalloc_fgetline(src_stream)) != NULL) {
127 void FAST_FUNC (*decode_fn_ptr)(FILE *src, FILE *dst, int flags);
128 char *line_ptr;
129 FILE *dst_stream;
130 int mode;
131
132 if (is_prefixed_with(line, "begin-base64 ")) {
133 line_ptr = line + 13;
134 decode_fn_ptr = read_base64;
135 } else if (is_prefixed_with(line, "begin ")) {
136 line_ptr = line + 6;
137 decode_fn_ptr = read_stduu;
138 } else {
139 free(line);
140 continue;
141 }
142
143 /* begin line found. decode and exit */
144 mode = bb_strtou(line_ptr, NULL, 8);
145 if (outname == NULL) {
146 outname = strchr(line_ptr, ' ');
147 if (!outname)
148 break;
149 outname++;
150 trim(outname); /* remove trailing space (and '\r' for DOS text) */
151 if (!outname[0])
152 break;
153 }
154 dst_stream = stdout;
155 if (NOT_LONE_DASH(outname)) {
156 dst_stream = xfopen_for_write(outname);
157 fchmod(fileno(dst_stream), mode & (S_IRWXU | S_IRWXG | S_IRWXO));
158 }
159 free(line);
160 decode_fn_ptr(src_stream, dst_stream, /*flags:*/ BASE64_FLAG_UU_STOP + BASE64_FLAG_NO_STOP_CHAR);
161 /* fclose_if_not_stdin(src_stream); - redundant */
162 return EXIT_SUCCESS;
163 }
164 bb_error_msg_and_die("no 'begin' line");
165}
166#endif
167
168//applet:IF_BASE64(APPLET(base64, BB_DIR_BIN, BB_SUID_DROP))
169
170//kbuild:lib-$(CONFIG_BASE64) += uudecode.o
171
172//config:config BASE64
173//config: bool "base64"
174//config: default y
175//config: help
176//config: Base64 encode and decode
177
178//usage:#define base64_trivial_usage
179//usage: "[-d] [FILE]"
180//usage:#define base64_full_usage "\n\n"
181//usage: "Base64 encode or decode FILE to standard output"
182//usage: "\n -d Decode data"
183////usage: "\n -w COL Wrap lines at COL (default 76, 0 disables)"
184////usage: "\n -i When decoding, ignore non-alphabet characters"
185
186#if ENABLE_BASE64
187int base64_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
188int base64_main(int argc UNUSED_PARAM, char **argv)
189{
190 FILE *src_stream;
191 unsigned opts;
192
193 opt_complementary = "?1"; /* 1 argument max */
194 opts = getopt32(argv, "d");
195 argv += optind;
196
197 if (!argv[0])
198 *--argv = (char*)"-";
199 src_stream = xfopen_stdin(argv[0]);
200 if (opts) {
201 read_base64(src_stream, stdout, /*flags:*/ (char)EOF);
202 } else {
203 enum {
204 SRC_BUF_SIZE = 76/4*3, /* This *MUST* be a multiple of 3 */
205 DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3),
206 };
207 char src_buf[SRC_BUF_SIZE];
208 char dst_buf[DST_BUF_SIZE + 1];
209 int src_fd = fileno(src_stream);
210 while (1) {
211 size_t size = full_read(src_fd, src_buf, SRC_BUF_SIZE);
212 if (!size)
213 break;
214 if ((ssize_t)size < 0)
215 bb_perror_msg_and_die(bb_msg_read_error);
216 /* Encode the buffer we just read in */
217 bb_uuencode(dst_buf, src_buf, size, bb_uuenc_tbl_base64);
218 xwrite(STDOUT_FILENO, dst_buf, 4 * ((size + 2) / 3));
219 bb_putchar('\n');
220 fflush(stdout);
221 }
222 }
223
224 fflush_stdout_and_exit(EXIT_SUCCESS);
225}
226#endif
227
228/* Test script.
229Put this into an empty dir with busybox binary, an run.
230
231#!/bin/sh
232test -x busybox || { echo "No ./busybox?"; exit; }
233ln -sf busybox uudecode
234ln -sf busybox uuencode
235>A_null
236echo -n A >A
237echo -n AB >AB
238echo -n ABC >ABC
239echo -n ABCD >ABCD
240echo -n ABCDE >ABCDE
241echo -n ABCDEF >ABCDEF
242cat busybox >A_bbox
243for f in A*; do
244 echo uuencode $f
245 ./uuencode $f <$f >u_$f
246 ./uuencode -m $f <$f >m_$f
247done
248mkdir unpk_u unpk_m 2>/dev/null
249for f in u_*; do
250 ./uudecode <$f -o unpk_u/${f:2}
251 diff -a ${f:2} unpk_u/${f:2} >/dev/null 2>&1
252 echo uudecode $f: $?
253done
254for f in m_*; do
255 ./uudecode <$f -o unpk_m/${f:2}
256 diff -a ${f:2} unpk_m/${f:2} >/dev/null 2>&1
257 echo uudecode $f: $?
258done
259*/
260
generated by cgit at 2024-05-15 09:54:29 (GMT)