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/* cksum.c - produce crc32 checksum value for each input
*
* Copyright 2008 Rob Landley <rob@landley.net>
*
* See http://opengroup.org/onlinepubs/9699919799/utilities/cksum.html
USE_CKSUM(NEWTOY(cksum, "HIPLN", TOYFLAG_BIN))
USE_CRC32(NEWTOY(crc32, 0, TOYFLAG_BIN))
config CKSUM
bool "cksum"
default y
help
usage: cksum [-IPLN] [FILE...]
For each file, output crc32 checksum value, length and name of file.
If no files listed, copy from stdin. Filename "-" is a synonym for stdin.
-H Hexadecimal checksum (defaults to decimal)
-L Little endian (defaults to big endian)
-P Pre-inversion
-I Skip post-inversion
-N Do not include length in CRC calculation (or output)
config CRC32
bool "crc32"
default y
help
usage: crc32 [file...]
Output crc32 checksum for each file.
*/
#define FOR_cksum
#define FORCE_FLAGS
#include "toys.h"
static void do_cksum(int fd, char *name)
{
unsigned crc_table[256], crc = FLAG(P) ? ~0 : 0;
unsigned long long llen = 0, llen2 = 0;
int len, i, done = 0;
// Init table, loop through data
crc_init(crc_table, FLAG(L));
for (;;) {
len = read(fd, toybuf, sizeof(toybuf));
if (len<0) perror_msg_raw(name);
if (len<1) {
// CRC the length at end
if (FLAG(N)) break;
for (llen2 = llen, len = 0; llen2; llen2 >>= 8) toybuf[len++] = llen2;
done++;
} else llen += len;
for (i = 0; i<len; i++)
crc = FLAG(L) ? crc_table[(crc^toybuf[i])&0xff] ^ (crc>>8)
: (crc<<8) ^ crc_table[(crc>>24)^toybuf[i]];
if (done) break;
}
printf(FLAG(H) ? "%08x" : "%u", FLAG(I) ? crc : ~crc);
if (!FLAG(N)) printf(" %llu", llen);
if (toys.optc) printf(" %s", name);
xputc('\n');
}
void cksum_main(void)
{
loopfiles(toys.optargs, do_cksum);
}
void crc32_main(void)
{
toys.optflags |= FLAG_H|FLAG_N|FLAG_P|FLAG_L;
if (toys.optc) toys.optc--;
cksum_main();
}
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