hush/coreutils/uuencode.c

181 lines
5.0 KiB
C

/* 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_CONFIG_BUFFER(src_buf, src_buf_size + 1);
RESERVE_CONFIG_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 = 0666 & ~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);
}