1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <string.h> 4 #include <stdint.h> 5 #include <unistd.h> 6 #include <fcntl.h> 7 #include <sys/ioctl.h> 8 #include <errno.h> 9 10 int cmp_main(int argc, char *argv[]) 11 { 12 int c; 13 int fd1, fd2; 14 char buf1[4096], buf2[4096]; 15 int res, res1, res2; 16 int rv = 0; 17 int i; 18 int filepos = 0; 19 20 int show_byte = 0; 21 int show_all = 0; 22 int limit = 0; 23 24 do { 25 c = getopt(argc, argv, "bln:"); 26 if (c == EOF) 27 break; 28 switch (c) { 29 case 'b': 30 show_byte = 1; 31 break; 32 case 'l': 33 show_all = 1; 34 break; 35 case 'n': 36 limit = atoi(optarg); 37 break; 38 case '?': 39 fprintf(stderr, "%s: invalid option -%c\n", 40 argv[0], optopt); 41 exit(1); 42 } 43 } while (1); 44 45 if (optind + 2 != argc) { 46 fprintf(stderr, "Usage: %s [-b] [-l] [-n count] file1 file2\n", argv[0]); 47 exit(1); 48 } 49 50 fd1 = open(argv[optind], O_RDONLY); 51 if(fd1 < 0) { 52 fprintf(stderr, "could not open %s, %s\n", argv[optind], strerror(errno)); 53 return 1; 54 } 55 56 fd2 = open(argv[optind+1], O_RDONLY); 57 if(fd2 < 0) { 58 fprintf(stderr, "could not open %s, %s\n", argv[optind+1], strerror(errno)); 59 return 1; 60 } 61 62 while(1) { 63 res1 = read(fd1, &buf1, sizeof(buf1)); 64 res2 = read(fd2, &buf2, sizeof(buf2)); 65 res = res1 < res2 ? res1 : res2; 66 if(res1 == 0 && res2 == 0) { 67 return rv; 68 } 69 for(i = 0; i < res; i++) { 70 if(buf1[i] != buf2[i]) { 71 printf("%s %s differ byte %d", argv[optind], argv[optind+1], filepos + i); 72 if(show_byte) 73 printf(" 0x%02x 0x%02x", buf1[i], buf2[i]); 74 printf("\n"); 75 if(!show_all) 76 return 1; 77 rv = 1; 78 } 79 if(limit) { 80 limit--; 81 if(limit == 0) 82 return rv; 83 } 84 } 85 if(res1 != res2 || res < 0) { 86 printf("%s on %s\n", res < 0 ? "Read error" : "EOF", res1 < res2 ? argv[optind] : argv[optind+1]); 87 return 1; 88 } 89 filepos += res; 90 } 91 } 92
