cmp.c 2.0 KB

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  1. #include <u.h>
  2. #include <libc.h>
  3. #define BUF 65536
  4. int sflag = 0;
  5. int lflag = 0;
  6. int Lflag = 0;
  7. static void usage(void);
  8. void
  9. main(int argc, char *argv[])
  10. {
  11. int n, i;
  12. uchar *p, *q;
  13. uchar buf1[BUF], buf2[BUF];
  14. int f1, f2;
  15. vlong nc = 1, o, l = 1;
  16. char *name1, *name2;
  17. uchar *b1s, *b1e, *b2s, *b2e;
  18. ARGBEGIN{
  19. case 's': sflag = 1; break;
  20. case 'l': lflag = 1; break;
  21. case 'L': Lflag = 1; break;
  22. default: usage();
  23. }ARGEND
  24. if(argc < 2)
  25. usage();
  26. if((f1 = open(name1 = *argv++, OREAD)) == -1){
  27. if(!sflag) perror(name1);
  28. exits("open");
  29. }
  30. if((f2 = open(name2 = *argv++, OREAD)) == -1){
  31. if(!sflag) perror(name2);
  32. exits("open");
  33. }
  34. if(*argv){
  35. o = strtoll(*argv++, 0, 0);
  36. if(seek(f1, o, 0) < 0){
  37. if(!sflag) perror("cmp: seek by offset1");
  38. exits("seek 1");
  39. }
  40. }
  41. if(*argv){
  42. o = strtoll(*argv++, 0, 0);
  43. if(seek(f2, o, 0) < 0){
  44. if(!sflag) perror("cmp: seek by offset2");
  45. exits("seek 2");
  46. }
  47. }
  48. if(*argv)
  49. usage();
  50. b1s = b1e = buf1;
  51. b2s = b2e = buf2;
  52. for(;;){
  53. if(b1s >= b1e){
  54. if(b1s >= &buf1[BUF])
  55. b1s = buf1;
  56. n = read(f1, b1s, &buf1[BUF] - b1s);
  57. b1e = b1s + n;
  58. }
  59. if(b2s >= b2e){
  60. if(b2s >= &buf2[BUF])
  61. b2s = buf2;
  62. n = read(f2, b2s, &buf2[BUF] - b2s);
  63. b2e = b2s + n;
  64. }
  65. n = b2e - b2s;
  66. if(n > b1e - b1s)
  67. n = b1e - b1s;
  68. if(n <= 0)
  69. break;
  70. if(memcmp((void *)b1s, (void *)b2s, n) != 0){
  71. if(sflag)
  72. exits("differ");
  73. for(p = b1s, q = b2s, i = 0; i < n; p++, q++, i++) {
  74. if(*p == '\n')
  75. l++;
  76. if(*p != *q){
  77. if(!lflag){
  78. print("%s %s differ: char %lld",
  79. name1, name2, nc+i);
  80. print(Lflag?" line %lld\n":"\n", l);
  81. exits("differ");
  82. }
  83. print("%6lld 0x%.2x 0x%.2x\n", nc+i, *p, *q);
  84. }
  85. }
  86. }
  87. if(Lflag)
  88. for(p = b1s; p < b1e;)
  89. if(*p++ == '\n')
  90. l++;
  91. nc += n;
  92. b1s += n;
  93. b2s += n;
  94. }
  95. if(b1e - b1s == b2e - b2s)
  96. exits((char *)0);
  97. if(!sflag)
  98. print("EOF on %s\n", (b1e - b1s > b2e - b2s)? name2 : name1);
  99. exits("EOF");
  100. }
  101. static void
  102. usage(void)
  103. {
  104. print("Usage: cmp [-lsL] file1 file2 [offset1 [offset2] ]\n");
  105. exits("usage");
  106. }