/* fgetstest.c */


#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>


int main(int /*@unused@*/argc, char **argv) {
  FILE *fp;
  char *line; 


  if ((fp = fopen ("test.txt", "r" )) == NULL ){
    fprintf (stderr, "%s: could not open file\n", argv[0]);
    exit (EXIT_FAILURE);
  }

  printf("reading first character of the first line from file:\n");
  if (fgets (line, 1, fp) != NULL)
    printf("%s",line);
  else
    printf("%s: could not read file\n", argv[0]);


  return 0;
 }

(gdb) break main                                                             
Breakpoint 1 at 0x80484c8: file fgetstest.c, line 12.                                     
(gdb) run                                                                    
Starting program: /home/eugen/sysprog/fgetstest                              


Breakpoint 1, main (argc=1, argv=0xbfcb1984) at fgetstest.c:12
12        if ((fp = fopen ("test.txt", "r" )) == NULL ){      
(gdb) step
17        printf("reading first character of the first line from file:\n");
(gdb) print fp                                                             
$1 = (FILE *) 0x804a008                                                    
(gdb) step                                                             
reading first character of the first line from file:
18        if (fgets (line, 1, fp) != NULL)
(gdb) print fp
$2 = (FILE *) 0x804a008
(gdb) print line
$3 = 0x80485a9 "\215�\030���\215\203\030���)���\002\205�t$1�\213E\020\211D$\b\213E\f\211D$\004\213E\b\211\004$�\224�\030���\203�\0019�u�\203�\f[^_]�\213\034$�\220\220U\211�S\203�\004��\226\004\b\203��t\0221���\213\203�\226\004\b\203�\004\203��u�\203�\004[]�\220\220\220U\211�S\203�\004�"
(gdb) step


Program received signal SIGSEGV, Segmentation fault.
0xb7debc42 in fgets () from /lib/tls/i686/cmov/libc.so.6