1  #include <stdio.h>
       2  #include <string.h>
       3  #include <stdlib.h>
       4  
       5  
       6  static int
       7  do_test (void)
       8  {
       9    size_t size;
      10    char *buf;
      11    FILE *fp = open_memstream (&buf, &size);
      12    if (fp == NULL)
      13      {
      14        puts ("open_memstream failed");
      15        return 1;
      16      }
      17  
      18    off64_t off = ftello64 (fp);
      19    if (off != 0)
      20      {
      21        puts ("initial position wrong");
      22        return 1;
      23      }
      24  
      25    if (fseek (fp, 32768, SEEK_SET) != 0)
      26      {
      27        puts ("fseek failed");
      28        return 1;
      29      }
      30  
      31    if (fputs ("foo", fp) == EOF)
      32      {
      33        puts ("fputs failed");
      34        return 1;
      35      }
      36  
      37    if (fclose (fp) == EOF)
      38      {
      39        puts ("fclose failed");
      40        return 1;
      41      }
      42  
      43    if (size != 32768 + 3)
      44      {
      45        printf ("expected size %d, got %zu\n", 32768 + 3, size);
      46        return 1;
      47      }
      48  
      49    for (int i = 0; i < 32768; ++i)
      50      if (buf[i] != '\0')
      51        {
      52  	printf ("byte at offset %d is %#hhx\n", i, buf[i]);
      53  	return 1;
      54        }
      55  
      56    if (memcmp (buf + 32768, "foo", 3) != 0)
      57      {
      58        puts ("written string incorrect");
      59        return 1;
      60      }
      61  
      62    /* Mark the buffer.  */
      63    memset (buf, 'A', size);
      64    free (buf);
      65  
      66    /* Try again, this time with write mode enabled before the seek.  */
      67    fp = open_memstream (&buf, &size);
      68    if (fp == NULL)
      69      {
      70        puts ("2nd open_memstream failed");
      71        return 1;
      72      }
      73  
      74    off = ftello64 (fp);
      75    if (off != 0)
      76      {
      77        puts ("2nd initial position wrong");
      78        return 1;
      79      }
      80  
      81    if (fputs ("bar", fp) == EOF)
      82      {
      83        puts ("2nd fputs failed");
      84        return 1;
      85      }
      86  
      87    if (fseek (fp, 32768, SEEK_SET) != 0)
      88      {
      89        puts ("2nd fseek failed");
      90        return 1;
      91      }
      92  
      93    if (fputs ("foo", fp) == EOF)
      94      {
      95        puts ("3rd fputs failed");
      96        return 1;
      97      }
      98  
      99    if (fclose (fp) == EOF)
     100      {
     101        puts ("2nd fclose failed");
     102        return 1;
     103      }
     104  
     105    if (size != 32768 + 3)
     106      {
     107        printf ("2nd expected size %d, got %zu\n", 32768 + 3, size);
     108        return 1;
     109      }
     110  
     111    if (memcmp (buf, "bar", 3) != 0)
     112      {
     113        puts ("initial string incorrect in 2nd try");
     114        return 1;
     115      }
     116  
     117    for (int i = 3; i < 32768; ++i)
     118      if (buf[i] != '\0')
     119        {
     120  	printf ("byte at offset %d is %#hhx in 2nd try\n", i, buf[i]);
     121  	return 1;
     122        }
     123  
     124    if (memcmp (buf + 32768, "foo", 3) != 0)
     125      {
     126        puts ("written string incorrect in 2nd try");
     127        return 1;
     128      }
     129  
     130    return 0;
     131  }
     132  
     133  #define TEST_FUNCTION do_test ()
     134  #include "../test-skeleton.c"