src/port/fseeko.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * fseeko.c
   4  *        64-bit versions of fseeko/ftello()
   5  *
   6  * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        $PostgreSQL: pgsql/src/port/fseeko.c,v 1.24 2010/01/02 16:58:13 momjian Exp $
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15
  16 /*
  17  * We have to use the native defines here because configure hasn't
  18  * completed yet.
  19  */
  20 #if defined(__bsdi__) || defined(__NetBSD__)
  21
  22 #include "c.h"
  23
  24 #ifdef bsdi
  25 #include <pthread.h>
  26 #endif
  27 #include <sys/stat.h>
  28
  29
  30 /*
  31  *      On BSD/OS and NetBSD, off_t and fpos_t are the same.  Standards
  32  *      say off_t is an arithmetic type, but not necessarily integral,
  33  *      while fpos_t might be neither.
  34  *
  35  *      This is thread-safe on BSD/OS using flockfile/funlockfile.
  36  */
  37
  38 int
  39 fseeko(FILE *stream, off_t offset, int whence)
  40 {
  41         off_t           floc;
  42         struct stat filestat;
  43
  44         switch (whence)
  45         {
  46                 case SEEK_CUR:
  47 #ifdef bsdi
  48                         flockfile(stream);
  49 #endif
  50                         if (fgetpos(stream, &floc) != 0)
  51                                 goto failure;
  52                         floc += offset;
  53                         if (fsetpos(stream, &floc) != 0)
  54                                 goto failure;
  55 #ifdef bsdi
  56                         funlockfile(stream);
  57 #endif
  58                         return 0;
  59                         break;
  60                 case SEEK_SET:
  61                         if (fsetpos(stream, &offset) != 0)
  62                                 return -1;
  63                         return 0;
  64                         break;
  65                 case SEEK_END:
  66 #ifdef bsdi
  67                         flockfile(stream);
  68 #endif
  69                         fflush(stream);         /* force writes to fd for stat() */
  70                         if (fstat(fileno(stream), &filestat) != 0)
  71                                 goto failure;
  72                         floc = filestat.st_size;
  73                         floc += offset;
  74                         if (fsetpos(stream, &floc) != 0)
  75                                 goto failure;
  76 #ifdef bsdi
  77                         funlockfile(stream);
  78 #endif
  79                         return 0;
  80                         break;
  81                 default:
  82                         errno = EINVAL;
  83                         return -1;
  84         }
  85
  86 failure:
  87 #ifdef bsdi
  88         funlockfile(stream);
  89 #endif
  90         return -1;
  91 }
  92
  93
  94 off_t
  95 ftello(FILE *stream)
  96 {
  97         off_t           floc;
  98
  99         if (fgetpos(stream, &floc) != 0)
 100                 return -1;
 101         return floc;
 102 }
 103
 104 #endif