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glibc  2.9
Functions
test_rdwr.c File Reference
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

Go to the source code of this file.

Functions

int main (int argc, char **argv)

Function Documentation

int main ( int  argc,
char **  argv 
)

Definition at line 26 of file test_rdwr.c.

{
  static const char hello[] = "Hello, world.\n";
  static const char replace[] = "Hewwo, world.\n";
  static const size_t replace_from = 2, replace_to = 4;
  char filename[FILENAME_MAX];
  char *name = strrchr (*argv, '/');
  char buf[BUFSIZ];
  FILE *f;
  int lose = 0;

  if (name != NULL)
    ++name;
  else
    name = *argv;

  (void) sprintf (filename, "/tmp/%s.test", name);

  f = fopen (filename, "w+");
  if (f == NULL)
    {
      perror (filename);
      exit (1);
    }

  (void) fputs (hello, f);
  rewind (f);
  (void) fgets (buf, sizeof (buf), f);
  rewind (f);
  (void) fputs (buf, f);
  rewind (f);
  {
    size_t i;
    for (i = 0; i < replace_from; ++i)
      {
       int c = getc (f);
       if (c == EOF)
         {
           printf ("EOF at %Zu.\n", i);
           lose = 1;
           break;
         }
       else if (c != hello[i])
         {
           printf ("Got '%c' instead of '%c' at %Zu.\n",
                  (unsigned char) c, hello[i], i);
           lose = 1;
           break;
         }
      }
  }

  {
    long int where = ftell (f);
    if (where == (long int) replace_from)
      {
       register size_t i;
       for (i = replace_from; i < replace_to; ++i)
         if (putc(replace[i], f) == EOF)
           {
             printf ("putc('%c') got %s at %Zu.\n",
                    replace[i], strerror (errno), i);
             lose = 1;
             break;
           }
      }
    else if (where == -1L)
      {
       printf ("ftell got %s (should be at %Zu).\n",
              strerror (errno), replace_from);
       lose = 1;
      }
    else
      {
       printf ("ftell returns %lu; should be %Zu.\n", where, replace_from);
       lose = 1;
      }
  }

  if (!lose)
    {
      rewind (f);
      if (fgets (buf, sizeof (buf), f) == NULL)
       {
         printf ("fgets got %s.\n", strerror(errno));
         lose = 1;
       }
      else if (strcmp (buf, replace))
       {
         printf ("Read \"%s\" instead of \"%s\".\n", buf, replace);
         lose = 1;
       }
    }

  if (lose)
    printf ("Test FAILED!  Losing file is \"%s\".\n", filename);
  else
    {
      (void) remove (filename);
      puts ("Test succeeded.");
    }

  return lose ? EXIT_FAILURE : EXIT_SUCCESS;
}

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