coreutils/pwd.c

   1 #include <errno.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <unistd.h>
   5
   6 /* Not yet posix, command line arguments not handled */
   7
   8 int not_posix = 0;
   9
  10 int main(void)
  11 {
  12     char *pathname;
  13     if(not_posix)
  14     {
  15         pathname = getcwd(0, 0); /* Not POSIX, but a reasonable option */
  16     }
  17     else
  18     {
  19         size_t i = 100;
  20         pathname = NULL;
  21         while(1)
  22         {
  23             pathname = realloc(pathname, i);
  24             if(! pathname)
  25             {
  26                 fputs("pwd: memory allocation failure", stderr);
  27                 return 1;
  28             }
  29
  30             if(getcwd(pathname, i))
  31                 break;
  32
  33             if(errno != ERANGE)
  34             {
  35                 perror("pwd");
  36                 free(pathname);
  37                 return 1;
  38             }
  39
  40             i += 100;
  41         }
  42     }
  43
  44     if((!not_posix || pathname) && puts(pathname) != EOF)
  45     {
  46         free(pathname);
  47         return 0;
  48     }
  49     else
  50     {
  51         perror("pwd");
  52         free(pathname);
  53         return 1;
  54     }
  55 }