summaryrefslogtreecommitdiff
path: root/coreutils/uuencode.c
blob: 1789aefbb43e67d73adefeb79554a41111385e4e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/* vi: set sw=4 ts=4: */
/*
 *  Copyright (C) 2000 by Glenn McGrath
 *
 *  based on the function base64_encode from http.c in wget v1.6
 *  Copyright (C) 1995, 1996, 1997, 1998, 2000 Free Software Foundation, Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Library General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include "busybox.h"

/* Conversion table.  for base 64 */
static char tbl_base64[64] = {
	'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
	'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
	'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
	'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
	'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
	'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
	'w', 'x', 'y', 'z', '0', '1', '2', '3',
	'4', '5', '6', '7', '8', '9', '+', '/'
};

static char tbl_std[64] = {
	'`', '!', '"', '#', '$', '%', '&', '\'',
	'(', ')', '*', '+', ',', '-', '.', '/',
	'0', '1', '2', '3', '4', '5', '6', '7',
	'8', '9', ':', ';', '<', '=', '>', '?',
	'@', 'A', 'B', 'C', 'D', 'E', 'F', 'G',
	'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
	'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
	'X', 'Y', 'Z', '[', '\\', ']', '^', '_'
};

/*
 * Encode the string S of length LENGTH to base64 format and place it
 * to STORE.  STORE will be 0-terminated, and must point to a writable
 * buffer of at least 1+BASE64_LENGTH(length) bytes.
 * where BASE64_LENGTH(len) = (4 * ((LENGTH + 2) / 3))
 */
static void uuencode (const char *s, const char *store, const int length, const char *tbl)
{
	int i;
	unsigned char *p = (unsigned char *)store;

	/* Transform the 3x8 bits to 4x6 bits, as required by base64.  */
	for (i = 0; i < length; i += 3) {
		*p++ = tbl[s[0] >> 2];
		*p++ = tbl[((s[0] & 3) << 4) + (s[1] >> 4)];
		*p++ = tbl[((s[1] & 0xf) << 2) + (s[2] >> 6)];
		*p++ = tbl[s[2] & 0x3f];
		s += 3;
	}
	/* Pad the result if necessary...  */
	if (i == length + 1) {
		*(p - 1) = '=';
	}
	else if (i == length + 2) {
		*(p - 1) = *(p - 2) = '=';
	}
	/* ...and zero-terminate it.  */
	*p = '\0';
}

int uuencode_main(int argc, char **argv)
{
	const int src_buf_size = 60;	// This *MUST* be a multiple of 3
	const int dst_buf_size = 4 * ((src_buf_size + 2) / 3);
	RESERVE_BB_BUFFER(src_buf, src_buf_size + 1);
	RESERVE_BB_BUFFER(dst_buf, dst_buf_size + 1);
	struct stat stat_buf;
	FILE *src_stream = stdin;
	char *tbl = tbl_std;
	size_t size;
	mode_t mode;
	int opt;
	int column = 0;
	int write_size = 0;
	int remaining;
	int buffer_offset = 0;

	while ((opt = getopt(argc, argv, "m")) != -1) {
		switch (opt) {
		case 'm':
			tbl = tbl_base64;
   			break;
		default:
			show_usage();
		}
	}

	switch (argc - optind) {
		case 2:
			src_stream = xfopen(argv[optind], "r");
			stat(argv[optind], &stat_buf);
			mode = stat_buf.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO);
			if (src_stream == stdout) {
				printf("NULL\n");
			}
			break;
		case 1:
			mode = umask(0666);
			break;
		default:
			show_usage();
	}

	printf("begin%s %o %s", tbl == tbl_std ? "" : "-base64", mode, argv[argc - 1]);

	while ((size = fread(src_buf, 1, src_buf_size, src_stream)) > 0) {
		/* Encode the buffer we just read in */
		uuencode(src_buf, dst_buf, size, tbl);

		/* Write the buffer to stdout, wrapping at 60 chars.
		 * This looks overly complex, but it gets tricky as
		 * the line has to continue to wrap correctly if we
		 * have to refill the buffer
		 *
		 * Improvments most welcome
		 */

		/* Initialise values for the new buffer */
		remaining = 4 * ((size + 2) / 3);
		buffer_offset = 0;

		/* Write the buffer to stdout, wrapping at 60 chars
		 * starting from the column the last buffer ran out
		 */
		do {
			if (remaining > (60 - column)) {
				write_size = 60 - column;
			}
			else if (remaining < 60) {
				write_size = remaining;
			} else {
				write_size = 60;
			}

			/* Setup a new row if required */
			if (column == 0) {
				putchar('\n');
				if (tbl == tbl_std) {
					putchar('M');
				}
			}
			/* Write to the 60th column */
			if (fwrite(&dst_buf[buffer_offset], 1, write_size, stdout) != write_size) {
				perror("Couldnt finish writing");
			}
			/* Update variables based on last write */
			buffer_offset += write_size;
			remaining -= write_size;
			column += write_size;
			if (column % 60 == 0) {
				column = 0;
			}
		} while (remaining > 0);
	}
	printf(tbl == tbl_std ? "\n`\nend\n" : "\n====\n");

	return(EXIT_SUCCESS);
}