libio/tst-mmap2-eofsync.c

   1 /* Test program for synchronization of stdio state with file after EOF.  */
   2
   3 #include <stdio.h>
   4 #include <error.h>
   5 #include <errno.h>
   6 #include <string.h>
   7 #include <unistd.h>
   8
   9 static void do_prepare (void);
  10 #define PREPARE(argc, argv) do_prepare ()
  11 static int do_test (void);
  12 #define TEST_FUNCTION do_test ()
  13 #include <test-skeleton.c>
  14
  15 static char *temp_file;
  16 static int temp_fd;
  17
  18 static char *pages;
  19
  20 static void
  21 do_prepare (void)
  22 {
  23   pages = xmalloc (getpagesize () * 2);
  24   memset (pages, 'a', getpagesize ());
  25   memset (pages + getpagesize (), 'b', getpagesize ());
  26
  27   temp_fd = create_temp_file ("tst-mmap2-eofsync.", &temp_file);
  28   if (temp_fd == -1)
  29     error (1, errno, "cannot create temporary file");
  30   else
  31     {
  32       ssize_t cc = write (temp_fd, pages, getpagesize ());
  33       if (cc != getpagesize ())
  34         error (1, errno, "cannot write to temporary file");
  35     }
  36 }
  37
  38 static int
  39 do_test (void)
  40 {
  41   const size_t pagesize = getpagesize ();
  42   FILE *f;
  43   char buf[pagesize];
  44   int result = 0;
  45   int c;
  46
  47   f = fopen (temp_file, "rm");
  48   if (f == NULL)
  49     {
  50       perror (temp_file);
  51       return 1;
  52     }
  53
  54   if (fread (buf, pagesize, 1, f) != 1)
  55     {
  56       perror ("fread");
  57       return 1;
  58     }
  59
  60   if (memcmp (buf, pages, pagesize))
  61     {
  62       puts ("data mismatch in page 1");
  63       result = 1;
  64     }
  65
  66   printf ("feof = %d, ferror = %d immediately after fread\n",
  67           feof (f), ferror (f));
  68
  69   c = fgetc (f);
  70   if (c == EOF)
  71     printf ("fgetc -> EOF (feof = %d, ferror = %d)\n",
  72             feof (f), ferror (f));
  73   else
  74     {
  75       printf ("fgetc returned %o (feof = %d, ferror = %d)\n",
  76               c, feof (f), ferror (f));
  77       result = 1;
  78     }
  79
  80   c = write (temp_fd, pages + pagesize, pagesize);
  81   if (c == (ssize_t) pagesize)
  82     printf ("wrote more to file\n");
  83   else
  84     {
  85       printf ("wrote %d != %zd (%m)\n", c, pagesize);
  86       result = 1;
  87     }
  88
  89   if (fread (buf, pagesize, 1, f) != 1)
  90     {
  91       printf ("second fread fails: feof = %d, ferror = %d (%m)\n",
  92               feof (f), ferror (f));
  93       clearerr (f);
  94       if (fread (buf, pagesize, 1, f) != 1)
  95         {
  96           printf ("retry fread fails: feof = %d, ferror = %d (%m)\n",
  97                   feof (f), ferror (f));
  98           result = 1;
  99         }
 100     }
 101   if (result == 0 && memcmp (buf, pages + pagesize, pagesize))
 102     {
 103       puts ("data mismatch in page 2");
 104       result = 1;
 105     }
 106
 107   fseek (f, pagesize - 1, SEEK_SET);
 108   c = fgetc (f);
 109   if (c != 'a')
 110     {
 111       printf ("fgetc at end of page 1 read '%c' (%m)\n", c);
 112       result = 1;
 113     }
 114
 115   if (ftruncate (temp_fd, pagesize) < 0)
 116     {
 117       printf ("ftruncate failed: %m\n");
 118       result = 1;
 119     }
 120
 121   fflush (f);
 122
 123   c = fgetc (f);
 124   if (c == EOF)
 125     printf ("after truncate fgetc -> EOF (feof = %d, ferror = %d)\n",
 126             feof (f), ferror (f));
 127   else
 128     {
 129       printf ("after truncate fgetc returned '%c' (feof = %d, ferror = %d)\n",
 130               c, feof (f), ferror (f));
 131       result = 1;
 132     }
 133
 134   fclose (f);
 135
 136   return result;
 137 }