1  #include <errno.h>
       2  #include <stdio.h>
       3  #include <stdlib.h>
       4  #include <unistd.h>
       5  
       6  
       7  static char fname[] = "/tmp/rndseek.XXXXXX";
       8  static char tempdata[65 * 1024];
       9  
      10  
      11  static int do_test (void);
      12  #define TEST_FUNCTION do_test ()
      13  
      14  #include "../test-skeleton.c"
      15  
      16  
      17  static int
      18  fp_test (const char *name, FILE *fp)
      19  {
      20    int result = 0;
      21    int rounds = 10000;
      22  
      23    do
      24      {
      25        int idx = random () % (sizeof (tempdata) - 2);
      26        char ch1;
      27        char ch2;
      28  
      29        if (fseek (fp, idx, SEEK_SET) != 0)
      30  	{
      31  	  printf ("%s: %d: fseek failed: %m\n", name, rounds);
      32  	  result = 1;
      33  	  break;
      34  	}
      35  
      36        ch1 = fgetc_unlocked (fp);
      37        ch2 = tempdata[idx];
      38        if (ch1 != ch2)
      39  	{
      40  	  printf ("%s: %d: character at index %d not what is expected ('%c' vs '%c')\n",
      41  		  name, rounds, idx, ch1, ch2);
      42  	  result = 1;
      43  	  break;
      44  	}
      45  
      46        ch1 = fgetc (fp);
      47        ch2 = tempdata[idx + 1];
      48        if (ch1 != ch2)
      49  	{
      50  	  printf ("%s: %d: character at index %d not what is expected ('%c' vs '%c')\n",
      51  		  name, rounds, idx + 1, ch1, ch2);
      52  	  result = 1;
      53  	  break;
      54  	}
      55      }
      56    while (--rounds > 0);
      57  
      58    fclose (fp);
      59  
      60    return result;
      61  }
      62  
      63  
      64  static int
      65  do_test (void)
      66  {
      67    int fd;
      68    FILE *fp;
      69    size_t i;
      70    int result;
      71  
      72    fd = mkstemp (fname);
      73    if (fd == -1)
      74      {
      75        printf ("cannot open temporary file: %m\n");
      76        return 1;
      77      }
      78    /* Make sure the file gets removed.  */
      79    add_temp_file (fname);
      80  
      81    /* Repeatability demands this.  */
      82    srandom (42);
      83  
      84    /* First create some temporary data.  */
      85    for (i = 0; i < sizeof (tempdata); ++i)
      86      tempdata[i] = 'a' + random () % 26;
      87  
      88    /* Write this data to a file.  */
      89    if (TEMP_FAILURE_RETRY (write (fd, tempdata, sizeof (tempdata)))
      90        != sizeof (tempdata))
      91      {
      92        printf ("cannot wrote data to temporary file: %m\n");
      93        return 1;
      94      }
      95  
      96    /* Now try reading the data.  */
      97    fp = fdopen (dup (fd), "r");
      98    if (fp == NULL)
      99      {
     100        printf ("cannot duplicate temporary file descriptor: %m\n");
     101        return 1;
     102      }
     103  
     104    rewind (fp);
     105    for (i = 0; i < sizeof (tempdata); ++i)
     106      {
     107        int ch0 = fgetc (fp);
     108        char ch1 = ch0;
     109        char ch2 = tempdata[i];
     110  
     111        if (ch0 == EOF)
     112  	{
     113  	  puts ("premature end of file while reading data");
     114  	  return 1;
     115  	}
     116  
     117        if (ch1 != ch2)
     118  	{
     119  	  printf ("%zd: '%c' vs '%c'\n", i, ch1, ch2);
     120  	  return 1;
     121  	}
     122      }
     123  
     124    result = fp_test ("fdopen(\"r\")", fp);
     125  
     126    fp = fopen (fname, "r");
     127    result |= fp_test ("fopen(\"r\")", fp);
     128  
     129    fp = fopen64 (fname, "r");
     130    result |= fp_test ("fopen64(\"r\")", fp);
     131  
     132    /* The "rw" mode will prevent the mmap-using code from being used.  */
     133    fp = fdopen (fd, "rw");
     134    result = fp_test ("fdopen(\"rw\")", fp);
     135  
     136    fp = fopen (fname, "rw");
     137    result |= fp_test ("fopen(\"rw\")", fp);
     138  
     139    fp = fopen64 (fname, "rw");
     140    result |= fp_test ("fopen64(\"rw\")", fp);
     141  
     142    return result;
     143  }