PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

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

       tmpnam — create a name for a temporary file

SYNOPSIS         top

       #include <stdio.h>

       char *tmpnam(char *s);

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 tmpnam() function shall generate a string that is a valid
       pathname that does not name an existing file. The function is
       potentially capable of generating {TMP_MAX} different strings, but
       any or all of them may already be in use by existing files and thus
       not be suitable return values.

       The tmpnam() function generates a different string each time it is
       called from the same process, up to {TMP_MAX} times. If it is called
       more than {TMP_MAX} times, the behavior is implementation-defined.

       The implementation shall behave as if no function defined in this
       volume of POSIX.1‐2008, except tempnam(), calls tmpnam().

       The tmpnam() function need not be thread-safe if called with a NULL
       parameter.

RETURN VALUE         top

       Upon successful completion, tmpnam() shall return a pointer to a
       string. If no suitable string can be generated, the tmpnam() function
       shall return a null pointer.

       If the argument s is a null pointer, tmpnam() shall leave its result
       in an internal static object and return a pointer to that object.
       Subsequent calls to tmpnam() may modify the same object. If the
       argument s is not a null pointer, it is presumed to point to an array
       of at least L_tmpnam chars; tmpnam() shall write its result in that
       array and shall return the argument as its value.

ERRORS         top

       No errors are defined.

       The following sections are informative.

EXAMPLES         top

   Generating a Pathname
       The following example generates a unique pathname and stores it in
       the array pointed to by ptr.

           #include <stdio.h>
           ...
           char pathname[L_tmpnam+1];
           char *ptr;

           ptr = tmpnam(pathname);

APPLICATION USAGE         top

       This function only creates pathnames. It is the application's
       responsibility to create and remove the files.

       Between the time a pathname is created and the file is opened, it is
       possible for some other process to create a file with the same name.
       Applications may find tmpfile() more useful.

       Applications should use the tmpfile(), mkstemp(), or mkdtemp()
       functions instead of the obsolescent tmpnam() function.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       The tmpnam() function may be removed in a future version.

SEE ALSO         top

       fopen(3p), open(3p), mkdtemp(3p), tempnam(3p), tmpfile(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 http://www.unix.org/online.html .

       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
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                          TMPNAM(3P)

Pages that refer to this page: stdio.h(0p)mkdtemp(3p)tempnam(3p)tmpfile(3p)