| 1 | #include <stdlib.h> |
| 2 | #include <stdio.h> |
| 3 | #include <unistd.h> |
| 4 | #include <fcntl.h> |
| 5 | #include <errno.h> |
| 6 | |
| 7 | char buf[65536]; |
| 8 | |
| 9 | void findnulls(int fd, char *source, int squelch) |
| 10 | { |
| 11 | int i, ret, n, s, off; |
| 12 | |
| 13 | n = 0; |
| 14 | s = -1; |
| 15 | off = 0; |
| 16 | while(1) { |
| 17 | ret = read(fd, buf, sizeof(buf)); |
| 18 | if(ret < 0) { |
| 19 | if(source != NULL) |
| 20 | perror(source); |
| 21 | else |
| 22 | perror("read"); |
| 23 | return; |
| 24 | } |
| 25 | for(i = 0; i < ret; i++) { |
| 26 | if(buf[i] == 0) { |
| 27 | if(s == -1) |
| 28 | s = off + i; |
| 29 | n++; |
| 30 | } else { |
| 31 | if(n > 0) { |
| 32 | if(n > squelch) { |
| 33 | if(source == NULL) |
| 34 | printf("%i %i\n", s, n); |
| 35 | else |
| 36 | printf("%s: %i %i\n", source, s, n); |
| 37 | } |
| 38 | s = -1; |
| 39 | n = 0; |
| 40 | } |
| 41 | } |
| 42 | } |
| 43 | off += ret; |
| 44 | if(ret == 0) |
| 45 | break; |
| 46 | } |
| 47 | if(n > squelch) { |
| 48 | if(source == NULL) |
| 49 | printf("%i %i\n", s, n); |
| 50 | else |
| 51 | printf("%s: %i %i\n", source, s, n); |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | int main(int argc, char **argv) |
| 56 | { |
| 57 | int i, c; |
| 58 | int squelch; |
| 59 | int fd; |
| 60 | |
| 61 | squelch = 1024; |
| 62 | while((c = getopt(argc, argv, "hs:")) >= 0) { |
| 63 | switch(c) { |
| 64 | case 's': |
| 65 | squelch = atoi(optarg); |
| 66 | break; |
| 67 | case 'h': |
| 68 | case '?': |
| 69 | case ':': |
| 70 | default: |
| 71 | fprintf(stderr, "usage: findnulls [-h] [-s squelch] [FILE...]\n"); |
| 72 | exit((c == 'h')?0:1); |
| 73 | } |
| 74 | } |
| 75 | if(optind < argc) { |
| 76 | for(i = optind; i < argc; i++) { |
| 77 | if((fd = open(argv[i], O_RDONLY)) < 0) { |
| 78 | perror(argv[i]); |
| 79 | continue; |
| 80 | } |
| 81 | findnulls(fd, argv[i], squelch); |
| 82 | close(fd); |
| 83 | } |
| 84 | } else { |
| 85 | findnulls(0, NULL, squelch); |
| 86 | } |
| 87 | return(0); |
| 88 | } |
| 89 | |
| 90 | /* |
| 91 | * Local Variables: |
| 92 | * compile-command: "gcc -Wall -g -o findnulls findnulls.c" |
| 93 | * End: |
| 94 | */ |