compiler/clib/tmpfile.c

   1 /*
   2     This file has been released into the Public Domain.
   3     $Id$
   4
   5     POSIX function tmpfile().
   6 */
   7
   8 #include <sys/param.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <errno.h>
  12 #include <fcntl.h>
  13 #include <proto/dos.h>
  14 #include <unistd.h>
  15
  16 /*****************************************************************************
  17
  18     NAME */
  19 #include <stdio.h>
  20
  21         FILE * tmpfile(
  22
  23 /*  SYNOPSIS */
  24         void)
  25
  26 /*  FUNCTION
  27         The tmpfile() function returns a pointer to a stream
  28         associated with a file descriptor returned by the routine
  29         mkstemp(3).  The created file is unlinked before tmpfile()
  30         returns, causing the file to be automatically deleted when the
  31         last reference to it is closed.  The file is opened with the
  32         access value `w+'.  The file is created in the T: directory,
  33         which is the standard AROS temp directory.
  34
  35
  36     INPUTS
  37
  38
  39     RESULT
  40         The tmpfile() function returns a pointer to an open file stream on
  41         success. On error, a NULL pointer is returned and errno is set
  42         appropriately.
  43
  44     ERRORS
  45         The tmpfile() function may fail and set the global variable
  46         errno for any of the errors specified for the library functions
  47         fdopen() or mkstemp().
  48
  49     NOTES
  50
  51     EXAMPLE
  52         #include <errno.h>
  53         #include <stdio.h>
  54         #include <string.h>
  55
  56         main()
  57         {
  58           FILE * fp;
  59
  60           fp = tmpfile();
  61           if ( fp == NULL)
  62           {
  63             perror(strerror(errno));
  64             return;
  65           }
  66
  67           fprintf(fp, "do a bit of writing to the temp file");
  68         }
  69
  70     BUGS
  71         BUG1: The temporary file is neither closed nor deleted. Ideally,
  72         unlink() could be used to mark the temp file for removal (see
  73         BUG1 in the source code) - but I suspect a bug in unlink() itself,
  74         whereby it tries to remove the file straight away, rather than
  75         waiting for all references to it to be closed. The bug is not too
  76         serious, because all temp files are written to the T: directory,
  77         which get zapped when AROS is closed down. However, problems may
  78         exist when you start creating over 26 temp files with the same PID.
  79
  80
  81     SEE ALSO
  82         fopen(), mkstemp()
  83
  84     INTERNALS
  85
  86 ******************************************************************************/
  87 {
  88   #define TEMPLATE "T:temp.XXXXXX"
  89   char * filename;
  90   FILE *fp;
  91
  92   filename = (char *)malloc(MAXPATHLEN);
  93   if (!filename) { puts("FIXME: mktemp() malloc failed"); return NULL;}
  94   strcpy(filename, TEMPLATE);
  95
  96   mktemp(filename);
  97   fp = fopen(filename, "w+");
  98   /* unlink(filename); -- see BUG1 in BUGS section */
  99   free(filename);
 100   return fp;
 101
 102 } /* tmpfile() */