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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 (consult 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  corre-
       sponding  stream. The file shall be automatically deleted when all ref-
       erences 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 processing  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,  Copyright  (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.opengroup.org/unix/online.html .

IEEE/The Open Group                  2003                          TMPFILE(3P)