diff options
Diffstat (limited to 'coreutils/uudecode.c')
| -rw-r--r-- | coreutils/uudecode.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/coreutils/uudecode.c b/coreutils/uudecode.c new file mode 100644 index 0000000..0298a4b --- /dev/null +++ b/coreutils/uudecode.c @@ -0,0 +1,224 @@ +/* vi: set sw=4 ts=4: */ +/* + * Copyright 2003, Glenn McGrath + * + * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + * + * Based on specification from + * http://www.opengroup.org/onlinepubs/007904975/utilities/uuencode.html + * + * Bugs: the spec doesn't mention anything about "`\n`\n" prior to the + * "end" line + */ + + +#include "libbb.h" + +static void read_stduu(FILE *src_stream, FILE *dst_stream) +{ + char *line; + + while ((line = xmalloc_fgetline(src_stream)) != NULL) { + int encoded_len, str_len; + char *line_ptr, *dst; + + if (strcmp(line, "end") == 0) { + return; /* the only non-error exit */ + } + + line_ptr = line; + while (*line_ptr) { + *line_ptr = (*line_ptr - 0x20) & 0x3f; + line_ptr++; + } + str_len = line_ptr - line; + + encoded_len = line[0] * 4 / 3; + /* Check that line is not too short. (we tolerate + * overly _long_ line to accomodate possible extra '`'). + * Empty line case is also caught here. */ + if (str_len <= encoded_len) { + break; /* go to bb_error_msg_and_die("short file"); */ + } + if (encoded_len <= 0) { + /* Ignore the "`\n" line, why is it even in the encode file ? */ + free(line); + continue; + } + if (encoded_len > 60) { + bb_error_msg_and_die("line too long"); + } + + dst = line; + line_ptr = line + 1; + do { + /* Merge four 6 bit chars to three 8 bit chars */ + *dst++ = line_ptr[0] << 2 | line_ptr[1] >> 4; + encoded_len--; + if (encoded_len == 0) { + break; + } + + *dst++ = line_ptr[1] << 4 | line_ptr[2] >> 2; + encoded_len--; + if (encoded_len == 0) { + break; + } + + *dst++ = line_ptr[2] << 6 | line_ptr[3]; + line_ptr += 4; + encoded_len -= 2; + } while (encoded_len > 0); + fwrite(line, 1, dst - line, dst_stream); + free(line); + } + bb_error_msg_and_die("short file"); +} + +static void read_base64(FILE *src_stream, FILE *dst_stream) +{ + int term_count = 1; + + while (1) { + char translated[4]; + int count = 0; + + while (count < 4) { + char *table_ptr; + int ch; + + /* Get next _valid_ character. + * global vector bb_uuenc_tbl_base64[] contains this string: + * "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=\n" + */ + do { + ch = fgetc(src_stream); + if (ch == EOF) { + bb_error_msg_and_die("short file"); + } + table_ptr = strchr(bb_uuenc_tbl_base64, ch); + } while (table_ptr == NULL); + + /* Convert encoded character to decimal */ + ch = table_ptr - bb_uuenc_tbl_base64; + + if (*table_ptr == '=') { + if (term_count == 0) { + translated[count] = '\0'; + break; + } + term_count++; + } else if (*table_ptr == '\n') { + /* Check for terminating line */ + if (term_count == 5) { + return; + } + term_count = 1; + continue; + } else { + translated[count] = ch; + count++; + term_count = 0; + } + } + + /* Merge 6 bit chars to 8 bit */ + if (count > 1) { + fputc(translated[0] << 2 | translated[1] >> 4, dst_stream); + } + if (count > 2) { + fputc(translated[1] << 4 | translated[2] >> 2, dst_stream); + } + if (count > 3) { + fputc(translated[2] << 6 | translated[3], dst_stream); + } + } +} + +int uudecode_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int uudecode_main(int argc UNUSED_PARAM, char **argv) +{ + FILE *src_stream; + char *outname = NULL; + char *line; + + opt_complementary = "?1"; /* 1 argument max */ + getopt32(argv, "o:", &outname); + argv += optind; + + if (!*argv) + *--argv = (char*)"-"; + src_stream = xfopen_stdin(*argv); + + /* Search for the start of the encoding */ + while ((line = xmalloc_fgetline(src_stream)) != NULL) { + void (*decode_fn_ptr)(FILE *src, FILE *dst); + char *line_ptr; + FILE *dst_stream; + int mode; + + if (strncmp(line, "begin-base64 ", 13) == 0) { + line_ptr = line + 13; + decode_fn_ptr = read_base64; + } else if (strncmp(line, "begin ", 6) == 0) { + line_ptr = line + 6; + decode_fn_ptr = read_stduu; + } else { + free(line); + continue; + } + + /* begin line found. decode and exit */ + mode = bb_strtou(line_ptr, NULL, 8); + if (outname == NULL) { + outname = strchr(line_ptr, ' '); + if ((outname == NULL) || (*outname == '\0')) { + break; + } + outname++; + } + dst_stream = stdout; + if (NOT_LONE_DASH(outname)) { + dst_stream = xfopen_for_write(outname); + fchmod(fileno(dst_stream), mode & (S_IRWXU | S_IRWXG | S_IRWXO)); + } + free(line); + decode_fn_ptr(src_stream, dst_stream); + /* fclose_if_not_stdin(src_stream); - redundant */ + return EXIT_SUCCESS; + } + bb_error_msg_and_die("no 'begin' line"); +} + +/* Test script. +Put this into an empty dir with busybox binary, an run. + +#!/bin/sh +test -x busybox || { echo "No ./busybox?"; exit; } +ln -sf busybox uudecode +ln -sf busybox uuencode +>A_null +echo -n A >A +echo -n AB >AB +echo -n ABC >ABC +echo -n ABCD >ABCD +echo -n ABCDE >ABCDE +echo -n ABCDEF >ABCDEF +cat busybox >A_bbox +for f in A*; do + echo uuencode $f + ./uuencode $f <$f >u_$f + ./uuencode -m $f <$f >m_$f +done +mkdir unpk_u unpk_m 2>/dev/null +for f in u_*; do + ./uudecode <$f -o unpk_u/${f:2} + diff -a ${f:2} unpk_u/${f:2} >/dev/null 2>&1 + echo uudecode $f: $? +done +for f in m_*; do + ./uudecode <$f -o unpk_m/${f:2} + diff -a ${f:2} unpk_m/${f:2} >/dev/null 2>&1 + echo uudecode $f: $? +done +*/ |