compiler/clib/mktemp.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <string.h>
   7 #include <proto/exec.h>
   8 #include <proto/dos.h>
   9 #include <dos/dos.h>
  10
  11 #include <exec/types.h>
  12 #include <assert.h>
  13
  14 /*****************************************************************************
  15
  16     NAME */
  17 #include <stdlib.h>
  18
  19         char *mktemp (
  20
  21 /*  SYNOPSIS */
  22         char *template)
  23
  24 /*  FUNCTION
  25         Make a unique temporary file name.
  26
  27     INPUTS
  28         template - template to change into unique filename
  29
  30     RESULT
  31         Returns template.
  32
  33     NOTES
  34         Template must end in "XXXXXX" (i.e at least 6 X's).
  35
  36         Prior to this paragraph being created, mktemp() sometimes produced filenames
  37         with '/' in them. AROS doesn't like that at all. Fortunately, the bug in this
  38         function which produced it has been fixed. -- blippy
  39
  40         For clarity, define the HEAD of the template to be the part before the tail,
  41         and the TAIL to be the succession of X's. So in, T:temp.XXXXXX , the head is
  42         T:temp. and the tail is XXXXXX .
  43
  44     EXAMPLE
  45
  46     BUGS
  47         Cannot create more than 26 filenames for the same process id. This is because
  48         the "bumping" is only done to the first tail character - it should be
  49         generalised to bump more characters if necessary.
  50
  51     SEE ALSO
  52
  53     INTERNALS
  54         Based on libnix mktemp
  55
  56 ******************************************************************************/
  57 {
  58     IPTR pid = (IPTR)FindTask(0L);
  59     char *c = template + strlen(template);
  60     BPTR  lock;
  61     IPTR remainder;
  62
  63     while (*--c == 'X')
  64     {
  65         remainder = pid % 10;
  66         assert(remainder>=0 && remainder<10);
  67         *c = remainder + '0';
  68         pid /= 10L;
  69     }
  70
  71     c++; /* ... c now points to the 1st char of the template tail */
  72
  73     /* If template errornously does not end in X c will point to '\0';
  74        exit gracefully
  75     */
  76     if (*c)
  77     {
  78         /* Loop over the first position of the tail, bumping it up as necessary */
  79         for(*c = 'A'; *c <= 'Z'; (*c)++)
  80         {
  81             if (!(lock = Lock(template, ACCESS_READ)))
  82                 return template;
  83             UnLock(lock);
  84         }
  85     }
  86
  87     return template;
  88 } /* mktemp */