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uudecode,base64: code shrink 

function                                             old     new   delta
read_base64                                          373     358     -15

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
1_18_stable
Denys Vlasenko 2010-09-01 13:24:05 +02:00
parent 0004e99493
commit 6f80fe71f0
1 changed files with 26 additions and 27 deletions
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53
coreutils/uudecode.c
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@ -77,18 +77,21 @@ static void read_stduu(FILE *src_stream, FILE *dst_stream)
static void read_base64(FILE *src_stream, FILE *dst_stream) static void read_base64(FILE *src_stream, FILE *dst_stream)
{ {
int term_count = 1; int term_count = 0;
while (1) { while (1) {
unsigned char translated[4]; unsigned char translated[4];
int count = 0; int count = 0;
/* Process one group of 4 chars */
while (count < 4) { while (count < 4) {
char *table_ptr; char *table_ptr;
int ch; int ch;
/* Get next _valid_ character. /* Get next _valid_ character.
* global vector bb_uuenc_tbl_base64[] contains this string: * bb_uuenc_tbl_base64[] contains this string:
* 0 1 2 3 4 5 6
* 012345678901234567890123456789012345678901234567890123456789012345
* "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=\n" * "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=\n"
*/ */
do { do {
@ -103,42 +106,38 @@ static void read_base64(FILE *src_stream, FILE *dst_stream)
bb_error_msg_and_die("short file"); bb_error_msg_and_die("short file");
} }
table_ptr = strchr(bb_uuenc_tbl_base64, ch); table_ptr = strchr(bb_uuenc_tbl_base64, ch);
} while (table_ptr == NULL); } while (!table_ptr);
/* Convert encoded character to decimal */ /* Convert encoded character to decimal */
ch = table_ptr - bb_uuenc_tbl_base64; ch = table_ptr - bb_uuenc_tbl_base64;
if (*table_ptr == '=') { if (ch == 65 /* '\n' */) {
if (term_count == 0) { /* Terminating "====" line? */
translated[count] = '\0'; if (term_count == 4)
break; return; /* yes */
}
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; term_count = 0;
continue;
} }
/* ch is 64 is char was '=', otherwise 0..63 */
translated[count] = ch & 63; /* 64 -> 0 */
if (ch == 64) {
term_count++;
break;
}
count++;
} }
/* Merge 6 bit chars to 8 bit */ /* Merge 6 bit chars to 8 bit.
if (count > 1) { * count can be < 4 when we decode the tail:
* "eQ==" -> "y", not "y NUL NUL"
*/
if (count > 1)
fputc(translated[0] << 2 | translated[1] >> 4, dst_stream); fputc(translated[0] << 2 | translated[1] >> 4, dst_stream);
} if (count > 2)
if (count > 2) {
fputc(translated[1] << 4 | translated[2] >> 2, dst_stream); fputc(translated[1] << 4 | translated[2] >> 2, dst_stream);
} if (count > 3)
if (count > 3) {
fputc(translated[2] << 6 | translated[3], dst_stream); fputc(translated[2] << 6 | translated[3], dst_stream);
} } /* while (1) */
}
} }
#if ENABLE_UUDECODE #if ENABLE_UUDECODE