compiler/clib/truncate.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     ANSI C function truncate().
   6 */
   7
   8 #include <unistd.h>
   9 #include <errno.h>
  10 #include <fcntl.h>
  11 #include "__errno.h"
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16 #include <unistd.h>
  17
  18         int truncate (
  19
  20 /*  SYNOPSIS */
  21         const char *path,
  22         off_t       length)
  23
  24 /*  FUNCTION
  25         Truncate a file to a specified length
  26
  27     INPUTS
  28         path   - the path of the file being truncated
  29         lenght - The file will have at most this size
  30
  31     RESULT
  32         0 on success or -1 on errorr.
  33
  34     NOTES
  35         If the file previously was larger than this size, the extra  data
  36         is  lost.   If  the  file  previously  was  shorter, it is
  37         unspecified whether the  file  is  left  unchanged  or  is
  38         extended.  In  the  latter case the extended part reads as
  39         zero bytes.
  40
  41
  42     EXAMPLE
  43
  44     BUGS
  45
  46     SEE ALSO
  47         open()
  48
  49     INTERNALS
  50
  51 ******************************************************************************/
  52 {
  53     int fd, ret = -1;
  54
  55     if (!path) /* safety check */
  56     {
  57         errno = EFAULT;
  58         return -1;
  59     }
  60
  61     if ((fd = open(path, O_WRONLY)) != -1)
  62     {
  63         ret = ftruncate(fd, length);
  64         close(fd);
  65     }
  66
  67     return ret;
  68 }