coreutils/cat.c

   1 #include <errno.h>
   2 #include <stdio.h>
   3 #include <string.h>
   4
   5 int main(int argc, char** argv)
   6 {
   7     int uflag = 0, retval = 0;
   8
   9     if(*argv && *++argv)
  10     {
  11         if(! strcmp(*argv, "-u"))
  12         {
  13             uflag = 1;
  14             setvbuf(stdout, NULL, _IONBF, 0);
  15             argv++;
  16         }
  17     }
  18
  19     do
  20     {
  21         FILE* input;
  22         if(! *argv || ! strcmp(*argv, "-"))
  23         {
  24             input = stdin;
  25         }
  26         else
  27         {
  28             input = fopen(*argv, "rb");
  29             if(! input)
  30             {
  31                 int temp = errno;
  32                 fprintf(stderr, "cat: can't open %s: ", *argv);
  33                 errno = temp;
  34                 perror(NULL);
  35                 retval = 1;
  36                 continue;
  37             }
  38         }
  39
  40         if(uflag)
  41             setvbuf(input, NULL, _IONBF, 0);
  42
  43         int c;
  44         while((c = fgetc(input)) != EOF)
  45         {
  46             if(putchar(c) == EOF)
  47             {
  48                 perror("cat: output failure");
  49                 return 1;
  50             }
  51         }
  52     } while (*argv && *++argv);
  53
  54     return retval;
  55 }