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 #define DEBUG 0
  15 #include <aros/debug.h>
  16
  17 /*****************************************************************************
  18
  19     NAME */
  20 #include <stdlib.h>
  21
  22         char *mktemp (
  23
  24 /*  SYNOPSIS */
  25         char *template)
  26
  27 /*  FUNCTION
  28         Make a unique temporary file name.
  29
  30     INPUTS
  31         template - template to change into unique filename
  32
  33     RESULT
  34         Returns template.
  35
  36     NOTES
  37         Template must end in "XXXXXX" (i.e at least 6 X's).
  38
  39         Prior to this paragraph being created, mktemp() sometimes produced filenames
  40         with '/' in them. AROS doesn't like that at all. Fortunately, the bug in this
  41         function which produced it has been fixed. -- blippy
  42
  43         For clarity, define the HEAD of the template to be the part before the tail,
  44         and the TAIL to be the succession of X's. So in, T:temp.XXXXXX , the head is
  45         T:temp. and the tail is XXXXXX .
  46
  47     EXAMPLE
  48
  49     BUGS
  50         Cannot create more than 26 filenames for the same process id. This is because
  51         the "bumping" is only done to the first tail character - it should be
  52         generalised to bump more characters if necessary.
  53
  54     SEE ALSO
  55
  56     INTERNALS
  57         Based on libnix mktemp
  58
  59 ******************************************************************************/
  60 {
  61     IPTR pid = (IPTR)FindTask(0L);
  62     char *c = template + strlen(template);
  63     BPTR  lock;
  64     IPTR remainder;
  65
  66     while (*--c == 'X')
  67     {
  68         remainder = pid % 10;
  69         assert(remainder>=0 && remainder<10);
  70         *c = remainder + '0';
  71         pid /= 10L;
  72     }
  73
  74     c++; /* ... c now points to the 1st char of the template tail */
  75
  76     /* If template errornously does not end in X c will point to '\0';
  77        exit gracefully
  78     */
  79     if (*c)
  80     {
  81         /* Loop over the first position of the tail, bumping it up as necessary */
  82         for(*c = 'A'; *c <= 'Z'; (*c)++)
  83         {
  84             if (!(lock = Lock(template, SHARED_LOCK)))
  85             {
  86                 if (IoErr() != ERROR_OBJECT_IN_USE)
  87                 {
  88                     D(bug("No lock (IoErr: %d); returning '%s'\n", IoErr(), template));
  89                     return template;
  90                 }
  91             }
  92             UnLock(lock);
  93         }
  94     }
  95
  96     D(bug("26 tries exhausted; Returning '%s'\n", template));
  97     return template;
  98 } /* mktemp */