TMPFILE(3P)                                         POSIX Programmer's Manual                                        TMPFILE(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       tmpfile - create a temporary file

SYNOPSIS
       #include <stdio.h>

       FILE *tmpfile(void);


DESCRIPTION
       The  tmpfile()  function  shall  create a temporary file and open a corresponding stream. The file shall be automatically
       deleted when all references to the file are closed. The file is opened as in fopen() for update (w+).

       In some implementations, a permanent file may be left behind if the process calling tmpfile() is killed while it is  pro-
       cessing a call to tmpfile().

       An error message may be written to standard error if the stream cannot be opened.

RETURN VALUE
       Upon  successful  completion,  tmpfile()  shall return a pointer to the stream of the file that is created. Otherwise, it
       shall return a null pointer  and set errno to indicate the error.

ERRORS
       The tmpfile() function shall fail if:

       EINTR  A signal was caught during tmpfile().

       EMFILE {OPEN_MAX} file descriptors are currently open in the calling process.

       ENFILE The maximum allowable number of files is currently open in the system.

       ENOSPC The directory or file system which would contain the new file cannot be expanded.

       EOVERFLOW
              The file is a regular file and the size of the file cannot be represented correctly in an object of type off_t.


       The tmpfile() function may fail if:

       EMFILE {FOPEN_MAX} streams are currently open in the calling process.

       ENOMEM Insufficient storage space is available.


       The following sections are informative.

EXAMPLES
   Creating a Temporary File
       The following example creates a temporary file for update, and returns a pointer to a stream for the created file in  the
       fp variable.


              #include <stdio.h>
              ...
              FILE *fp;


              fp = tmpfile ();

APPLICATION USAGE
       It  should  be  possible to open at least {TMP_MAX} temporary files during the lifetime of the program (this limit may be
       shared with tmpnam()) and there should be no limit on the number simultaneously open other than this limit and any  limit
       on the number of open files ( {FOPEN_MAX}).

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       fopen(), tmpnam(), unlink(), the Base Definitions volume of IEEE Std 1003.1-2001, <stdio.h>

COPYRIGHT
       Portions  of  this  text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for
       Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6,  Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open  Group
       Standard   is   the   referee   document.   The   original   Standard   can   be   obtained  online  at  http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                   TMPFILE(3P)