1  /* Test for bug in fflush synchronization behavior.  */
       2  
       3  #include <stdio.h>
       4  #include <stdlib.h>
       5  #include <string.h>
       6  
       7  #include <support/xstdlib.h>
       8  
       9  static char *fname;
      10  
      11  static void prepare (void);
      12  #define PREPARE(argc, argv) prepare ()
      13  
      14  
      15  #define TEST_FUNCTION do_test ()
      16  static int do_test (void);
      17  #include "../test-skeleton.c"
      18  
      19  
      20  static void
      21  prepare (void)
      22  {
      23    int fd = create_temp_file ("bug-mmap-fflush.", &fname);
      24    if (fd == -1)
      25      exit (3);
      26    /* We don't need the descriptor.  */
      27    close (fd);
      28  }
      29  
      30  
      31  static int
      32  do_test (void)
      33  {
      34    FILE *f;
      35    off_t o;
      36    char buffer[1024];
      37  
      38    snprintf (buffer, sizeof (buffer), "echo 'From foo@bar.com' > %s", fname);
      39    xsystem (buffer);
      40  
      41    f = fopen (fname, "r");
      42    fseek (f, 0, SEEK_END);
      43    o = ftello (f);
      44    fseek (f, 0, SEEK_SET);
      45    fflush (f);
      46    snprintf (buffer, sizeof (buffer), "echo 'From bar@baz.edu' >> %s", fname);
      47    xsystem (buffer);
      48  
      49    fseek (f, o, SEEK_SET);
      50    if (fgets (buffer, 1024, f) == NULL)
      51      exit (1);
      52    if (strncmp (buffer, "From ", 5) != 0)
      53      exit (1);
      54    fclose (f);
      55    exit (0);
      56  }