libio/tst-mmap-fflushsync.c

   1 /* Test program for synchronization of stdio state with file after fflush.  */
   2
   3 #include <stdio.h>
   4 #include <error.h>
   5 #include <errno.h>
   6
   7 static void do_prepare (void);
   8 #define PREPARE(argc, argv) do_prepare ()
   9 static int do_test (void);
  10 #define TEST_FUNCTION do_test ()
  11 #include <test-skeleton.c>
  12
  13 static char *temp_file;
  14 static int temp_fd;
  15
  16 static char text1[] = "Line the first\n";
  17 static char text2[] = "Line the second\n";
  18
  19 static void
  20 do_prepare (void)
  21 {
  22   temp_fd = create_temp_file ("tst-mmap-eofsync.", &temp_file);
  23   if (temp_fd == -1)
  24     error (1, errno, "cannot create temporary file");
  25   else
  26     {
  27       ssize_t cc = write (temp_fd, text1, sizeof text1 - 1);
  28       if (cc != sizeof text1 - 1)
  29         error (1, errno, "cannot write to temporary file");
  30     }
  31 }
  32
  33 static int
  34 do_test (void)
  35 {
  36   FILE *f;
  37   char buf[128];
  38   int result = 0;
  39   int c;
  40
  41   f = fopen (temp_file, "rm");
  42   if (f == NULL)
  43     {
  44       perror (temp_file);
  45       return 1;
  46     }
  47
  48   if (fgets (buf, sizeof buf, f) == NULL)
  49     {
  50       perror ("fgets");
  51       return 1;
  52     }
  53
  54   if (strcmp (buf, text1))
  55     {
  56       printf ("read \"%s\", expected \"%s\"\n", buf, text1);
  57       result = 1;
  58     }
  59
  60   printf ("feof = %d, ferror = %d immediately after fgets\n",
  61           feof (f), ferror (f));
  62
  63   if (fflush (f) != 0)
  64     {
  65       printf ("fflush failed! %m\n");
  66       result = 1;
  67     }
  68
  69   c = write (temp_fd, text2, sizeof text2 - 1);
  70   if (c == sizeof text2 - 1)
  71     printf ("wrote more to file\n");
  72   else
  73     {
  74       printf ("wrote %d != %zd (%m)\n", c, sizeof text2 - 1);
  75       result = 1;
  76     }
  77
  78   if (fgets (buf, sizeof buf, f) == NULL)
  79     {
  80       printf ("second fgets fails: feof = %d, ferror = %d (%m)\n",
  81               feof (f), ferror (f));
  82       clearerr (f);
  83       if (fgets (buf, sizeof buf, f) == NULL)
  84         {
  85           printf ("retry fgets fails: feof = %d, ferror = %d (%m)\n",
  86                   feof (f), ferror (f));
  87           result = 1;
  88         }
  89     }
  90   if (result == 0 && strcmp (buf, text2))
  91     {
  92       printf ("second time read \"%s\", expected \"%s\"\n", buf, text2);
  93       result = 1;
  94     }
  95
  96   fclose (f);
  97
  98   return result;
  99 }