diff options
Diffstat (limited to 'toys/posix/cksum.c')
| -rw-r--r-- | toys/posix/cksum.c | 107 |
1 files changed, 52 insertions, 55 deletions
diff --git a/toys/posix/cksum.c b/toys/posix/cksum.c index 3e27b4cb..1192077c 100644 --- a/toys/posix/cksum.c +++ b/toys/posix/cksum.c @@ -1,6 +1,4 @@ -/* vi: set sw=4 ts=4: - * - * cksum.c - produce crc32 checksum value for each input +/* cksum.c - produce crc32 checksum value for each input * * Copyright 2008 Rob Landley <rob@landley.net> * @@ -9,78 +7,77 @@ USE_CKSUM(NEWTOY(cksum, "IPLN", 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. - - -L Little endian (defaults to big endian) - -P Pre-inversion - -I Skip post-inversion - -N Do not include length in CRC calculation + 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. + + -L Little endian (defaults to big endian) + -P Pre-inversion + -I Skip post-inversion + -N Do not include length in CRC calculation */ #define FOR_cksum #include "toys.h" GLOBALS( - unsigned crc_table[256]; + unsigned crc_table[256]; ) static unsigned cksum_be(unsigned crc, unsigned char c) { - return (crc<<8)^TT.crc_table[(crc>>24)^c]; + return (crc<<8)^TT.crc_table[(crc>>24)^c]; } static unsigned cksum_le(unsigned crc, unsigned char c) { - return TT.crc_table[(crc^c)&0xff] ^ (crc>>8); + return TT.crc_table[(crc^c)&0xff] ^ (crc>>8); } static void do_cksum(int fd, char *name) { - unsigned crc = (toys.optflags&4) ? 0xffffffff : 0; - uint64_t llen = 0, llen2; - unsigned (*cksum)(unsigned crc, unsigned char c); - - - cksum = (toys.optflags&2) ? cksum_le : cksum_be; - // CRC the data - - for (;;) { - int len, i; - - len = read(fd, toybuf, sizeof(toybuf)); - if (len<0) { - perror_msg("%s",name); - toys.exitval = EXIT_FAILURE; - } - if (len<1) break; - - llen += len; - for (i=0; i<len; i++) crc=cksum(crc, toybuf[i]); - } - - // CRC the length - - llen2 = llen; - if (!(toys.optflags&1)) { - while (llen) { - crc = cksum(crc, llen); - llen >>= 8; - } - } - - printf("%u %"PRIu64, (toys.optflags&8) ? crc : ~crc, llen2); - if (strcmp("-", name)) printf(" %s", name); - xputc('\n'); + unsigned crc = (toys.optflags&4) ? 0xffffffff : 0; + uint64_t llen = 0, llen2; + unsigned (*cksum)(unsigned crc, unsigned char c); + + cksum = (toys.optflags&2) ? cksum_le : cksum_be; + // CRC the data + + for (;;) { + int len, i; + + len = read(fd, toybuf, sizeof(toybuf)); + if (len<0) { + perror_msg("%s",name); + toys.exitval = EXIT_FAILURE; + } + if (len<1) break; + + llen += len; + for (i=0; i<len; i++) crc=cksum(crc, toybuf[i]); + } + + // CRC the length + + llen2 = llen; + if (!(toys.optflags&1)) { + while (llen) { + crc = cksum(crc, llen); + llen >>= 8; + } + } + + printf("%u %"PRIu64, (toys.optflags&8) ? crc : ~crc, llen2); + if (strcmp("-", name)) printf(" %s", name); + xputc('\n'); } void cksum_main(void) { - crc_init(TT.crc_table, toys.optflags&2); - loopfiles(toys.optargs, do_cksum); + crc_init(TT.crc_table, toys.optflags&2); + loopfiles(toys.optargs, do_cksum); } |