velilla@island.dec.com (Juan Velilla) (02/25/90)
> > > > > I'm in the process of learning unix through the use of MINIX. I have a simple question regarding crc's; I'm running P-H v1.3 and I'm the process to update to v1.5. In postings by Andy there is a listing of crcs for v1.3, v1.4 and v1.5, he recomends that crcs for v1.3 should be checked, now.... the only command that I found in Minix to checksum a file is "sum" ,is there any other command???? as and example I tried to check file utmp.h with sum and I get the value of 22540 and in the listing the value is 13220. Non of the values that I get from my files using sum, match the listings, at least the size of the files match, for the example, the size utmp.h is 217. Could someone help me in getting the correct crcs from my files or tell me what I'm doing wrong............ Velilla
ast@cs.vu.nl (Andy Tanenbaum) (02/26/90)
In article <1395@mountn.dec.com> velilla@island.dec.com (Juan Velilla) writes: >the only command that I found in Minix to checksum a file >is "sum" ,is there any other command???? Yes. The MINIX standard for checksumming is NOT sum, but a program called crc written by Johan Stevenson. It has a stronger checksum and also prints the file length. Since this question comes up repeatedly, here it is again. Andy Tanenbaum (ast@cs.vu.nl) /* Compute checksum Author: Johan W. Stevenson */ #include <stdio.h> int errs; main(argc, argv) char **argv; { char line[256]; if (argc <= 1) crc((char *) 0); else if (argc == 2 && strcmp(argv[1], "-") == 0) while (fgets(line, sizeof line, stdin) != NULL) { if (line[strlen(line) - 1] = '\n') line[strlen(line) - 1] = '\0'; crc(line); } else do { crc(argv[1]); argv++; argc--; } while (argc > 1); exit(errs != 0); } /* Crctab calculated by Mark G. Mendel, Network Systems Corporation */ static unsigned short crctab[256] = { 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7, 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef, 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6, 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de, 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485, 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d, 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4, 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc, 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823, 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b, 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12, 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a, 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41, 0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49, 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70, 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78, 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f, 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067, 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e, 0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256, 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d, 0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405, 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c, 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634, 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab, 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3, 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a, 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92, 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9, 0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1, 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8, 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0 }; /* Updcrc macro derived from article Copyright (C) 1986 Stephen Satchell. * NOTE: First argument must be in range 0 to 255. * Second argument is referenced twice. * * Programmers may incorporate any or all code into their programs, * giving proper credit within the source. Publication of the * source routines is permitted so long as proper credit is given * to Stephen Satchell, Satchell Evaluations and Chuck Forsberg, * Omen Technology. */ #define updcrc(cp, crc) ( crctab[((crc >> 8) & 255)] ^ (crc << 8) ^ cp) crc(fname) char *fname; { register int c; register int i; register long len = 0; register unsigned short crc = 0; register FILE *fp; if (fname == NULL) fp = stdin; else if ((fp = fopen(fname, "r")) == NULL) { fprintf(stderr, "crc: cannot open %s\n", fname); errs++; return; } while ((c = getc(fp)) != EOF) { len++; crc = updcrc(c, crc); } printf("%05u %6ld", crc, len); if (fname) { printf(" %s", fname); fclose(fp); } printf("\n"); }