1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <string.h> 4 #include <stdint.h> 5 #include <fcntl.h> 6 #include <sys/ioctl.h> 7 #include <errno.h> 8 9 int cmp_main(int argc, char *argv[]) 10 { 11 int c; 12 int fd1, fd2; 13 char buf1[4096], buf2[4096]; 14 int res, res1, res2; 15 int rv = 0; 16 int i; 17 int filepos = 0; 18 19 int show_byte = 0; 20 int show_all = 0; 21 int limit = 0; 22 23 do { 24 c = getopt(argc, argv, "bln:"); 25 if (c == EOF) 26 break; 27 switch (c) { 28 case 'b': 29 show_byte = 1; 30 break; 31 case 'l': 32 show_all = 1; 33 break; 34 case 'n': 35 limit = atoi(optarg); 36 break; 37 case '?': 38 fprintf(stderr, "%s: invalid option -%c\n", 39 argv[0], optopt); 40 exit(1); 41 } 42 } while (1); 43 44 if (optind + 2 != argc) { 45 fprintf(stderr, "Usage: %s [-b] [-l] [-n count] file1 file2\n", argv[0]); 46 exit(1); 47 } 48 49 fd1 = open(argv[optind], O_RDONLY); 50 if(fd1 < 0) { 51 fprintf(stderr, "could not open %s, %s\n", argv[optind], strerror(errno)); 52 return 1; 53 } 54 55 fd2 = open(argv[optind+1], O_RDONLY); 56 if(fd2 < 0) { 57 fprintf(stderr, "could not open %s, %s\n", argv[optind+1], strerror(errno)); 58 return 1; 59 } 60 61 while(1) { 62 res1 = read(fd1, &buf1, sizeof(buf1)); 63 res2 = read(fd2, &buf2, sizeof(buf2)); 64 res = res1 < res2 ? res1 : res2; 65 if(res1 == 0 && res2 == 0) { 66 return rv; 67 } 68 for(i = 0; i < res; i++) { 69 if(buf1[i] != buf2[i]) { 70 printf("%s %s differ byte %d", argv[optind], argv[optind+1], filepos + i); 71 if(show_byte) 72 printf(" 0x%02x 0x%02x", buf1[i], buf2[i]); 73 printf("\n"); 74 if(!show_all) 75 return 1; 76 rv = 1; 77 } 78 if(limit) { 79 limit--; 80 if(limit == 0) 81 return rv; 82 } 83 } 84 if(res1 != res2 || res < 0) { 85 printf("%s on %s\n", res < 0 ? "Read error" : "EOF", res1 < res2 ? argv[optind] : argv[optind+1]); 86 return 1; 87 } 88 filepos += res; 89 } 90 } 91
