get-tar-commit-id.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <unistd.h>
   4
   5 #define HEADERSIZE      1024
   6
   7 int main(int argc, char **argv)
   8 {
   9         char buffer[HEADERSIZE];
  10         ssize_t n;
  11
  12         n = read(0, buffer, HEADERSIZE);
  13         if (n < HEADERSIZE) {
  14                 fprintf(stderr, "read error\n");
  15                 return 3;
  16         }
  17         if (buffer[156] != 'g')
  18                 return 1;
  19         if (memcmp(&buffer[512], "52 comment=", 11))
  20                 return 1;
  21         n = write(1, &buffer[523], 41);
  22         if (n < 41) {
  23                 fprintf(stderr, "write error\n");
  24                 return 2;
  25         }
  26         return 0;
  27 }