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

PROLOG         top

       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         top

       tmpfile — create a temporary file

SYNOPSIS         top

       #include <stdio.h>

       FILE *tmpfile(void);

DESCRIPTION         top

       The functionality described on this reference page is aligned with
       the ISO C standard. Any conflict between the requirements described
       here and the ISO C standard is unintentional. This volume of
       POSIX.1‐2008 defers to the ISO C standard.

       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+), except that implementations may restrict the
       permissions, either by clearing the file mode bits or setting them to
       the value S_IRUSR | S_IWUSR.

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

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

RETURN VALUE         top

       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         top

       The tmpfile() function shall fail if:

       EINTR  A signal was caught during tmpfile().

       EMFILE All file descriptors available to the process are currently

       EMFILE {STREAM_MAX} streams are currently open in the calling

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

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

              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         top

   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

           #include <stdio.h>
           FILE *fp;

           fp = tmpfile ();


       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 file
       descriptors or streams ({OPEN_MAX}, {FOPEN_MAX}, {STREAM_MAX}).

RATIONALE         top




SEE ALSO         top

       Section 2.5, Standard I/O Streams, fopen(3p), mkdtemp(3p),
       tmpnam(3p), unlink(3p)

       The Base Definitions volume of POSIX.1‐2008, stdio.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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 .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see .

IEEE/The Open Group                 2013                         TMPFILE(3P)