| [9] | 1 | /* sum - checksum a file Author: Martin C. Atkins */
|
|---|
| 2 |
|
|---|
| 3 | /*
|
|---|
| 4 | * This program was written by:
|
|---|
| 5 | * Martin C. Atkins,
|
|---|
| 6 | * University of York,
|
|---|
| 7 | * Heslington,
|
|---|
| 8 | * York. Y01 5DD
|
|---|
| 9 | * England
|
|---|
| 10 | * and is released into the public domain, on the condition
|
|---|
| 11 | * that this comment is always included without alteration.
|
|---|
| 12 | */
|
|---|
| 13 |
|
|---|
| 14 | #include <sys/types.h>
|
|---|
| 15 | #include <fcntl.h>
|
|---|
| 16 | #include <stdlib.h>
|
|---|
| 17 | #include <unistd.h>
|
|---|
| 18 | #include <minix/minlib.h>
|
|---|
| 19 | #include <stdio.h>
|
|---|
| 20 |
|
|---|
| 21 | #define BUFFER_SIZE (512)
|
|---|
| 22 |
|
|---|
| 23 | int rc = 0;
|
|---|
| 24 |
|
|---|
| 25 | char *defargv[] = {"-", 0};
|
|---|
| 26 |
|
|---|
| 27 | _PROTOTYPE(int main, (int argc, char **argv));
|
|---|
| 28 | _PROTOTYPE(void error, (char *s, char *f));
|
|---|
| 29 | _PROTOTYPE(void sum, (int fd, char *fname));
|
|---|
| 30 | _PROTOTYPE(void putd, (int number, int fw, int zeros));
|
|---|
| 31 |
|
|---|
| 32 | int main(argc, argv)
|
|---|
| 33 | int argc;
|
|---|
| 34 | char *argv[];
|
|---|
| 35 | {
|
|---|
| 36 | register int fd;
|
|---|
| 37 |
|
|---|
| 38 | if (*++argv == 0) argv = defargv;
|
|---|
| 39 | for (; *argv; argv++) {
|
|---|
| 40 | if (argv[0][0] == '-' && argv[0][1] == '\0')
|
|---|
| 41 | fd = 0;
|
|---|
| 42 | else
|
|---|
| 43 | fd = open(*argv, O_RDONLY);
|
|---|
| 44 |
|
|---|
| 45 | if (fd == -1) {
|
|---|
| 46 | error("can't open ", *argv);
|
|---|
| 47 | rc = 1;
|
|---|
| 48 | continue;
|
|---|
| 49 | }
|
|---|
| 50 | sum(fd, (argc > 2) ? *argv : (char *) 0);
|
|---|
| 51 | if (fd != 0) close(fd);
|
|---|
| 52 | }
|
|---|
| 53 | return(rc);
|
|---|
| 54 | }
|
|---|
| 55 |
|
|---|
| 56 | void error(s, f)
|
|---|
| 57 | char *s, *f;
|
|---|
| 58 | {
|
|---|
| 59 |
|
|---|
| 60 | std_err("sum: ");
|
|---|
| 61 | std_err(s);
|
|---|
| 62 |
|
|---|
| 63 | if (f) std_err(f);
|
|---|
| 64 | std_err("\n");
|
|---|
| 65 | }
|
|---|
| 66 |
|
|---|
| 67 | void sum(fd, fname)
|
|---|
| 68 | int fd;
|
|---|
| 69 | char *fname;
|
|---|
| 70 | {
|
|---|
| 71 | char buf[BUFFER_SIZE];
|
|---|
| 72 | register int i, n;
|
|---|
| 73 | long size = 0;
|
|---|
| 74 | unsigned crc = 0;
|
|---|
| 75 | unsigned tmp, blks;
|
|---|
| 76 |
|
|---|
| 77 | while ((n = read(fd, buf, BUFFER_SIZE)) > 0) {
|
|---|
| 78 | for (i = 0; i < n; i++) {
|
|---|
| 79 | crc = (crc >> 1) + ((crc & 1) ? 0x8000 : 0);
|
|---|
| 80 | tmp = buf[i] & 0377;
|
|---|
| 81 | crc += tmp;
|
|---|
| 82 | crc &= 0xffff;
|
|---|
| 83 | size++;
|
|---|
| 84 | }
|
|---|
| 85 | }
|
|---|
| 86 |
|
|---|
| 87 | if (n < 0) {
|
|---|
| 88 | if (fname)
|
|---|
| 89 | error("read error on ", fname);
|
|---|
| 90 | else
|
|---|
| 91 | error("read error", (char *) 0);
|
|---|
| 92 | rc = 1;
|
|---|
| 93 | return;
|
|---|
| 94 | }
|
|---|
| 95 | putd(crc, 5, 1);
|
|---|
| 96 | blks = (size + (long) BUFFER_SIZE - 1L) / (long) BUFFER_SIZE;
|
|---|
| 97 | putd(blks, 6, 0);
|
|---|
| 98 | if (fname) printf(" %s", fname);
|
|---|
| 99 | printf("\n");
|
|---|
| 100 | }
|
|---|
| 101 |
|
|---|
| 102 | void putd(number, fw, zeros)
|
|---|
| 103 | int number, fw, zeros;
|
|---|
| 104 | {
|
|---|
| 105 | /* Put a decimal number, in a field width, to stdout. */
|
|---|
| 106 |
|
|---|
| 107 | char buf[10];
|
|---|
| 108 | int n;
|
|---|
| 109 | unsigned num;
|
|---|
| 110 |
|
|---|
| 111 | num = (unsigned) number;
|
|---|
| 112 | for (n = 0; n < fw; n++) {
|
|---|
| 113 | if (num || n == 0) {
|
|---|
| 114 | buf[fw - n - 1] = '0' + num % 10;
|
|---|
| 115 | num /= 10;
|
|---|
| 116 | } else
|
|---|
| 117 | buf[fw - n - 1] = zeros ? '0' : ' ';
|
|---|
| 118 | }
|
|---|
| 119 | buf[fw] = 0;
|
|---|
| 120 | printf("%s", buf);
|
|---|
| 121 | }
|
|---|
