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TMPNAM(3P)                 POSIX Programmer's Manual                TMPNAM(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
       tmpnam -- create a name for a temporary file
SYNOPSIS
       #include <stdio.h>
       char *tmpnam(char *s);
DESCRIPTION
       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  capa-
       ble  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 vol-
       ume of POSIX.1-2008, except tempnam(), calls tmpnam().
       The tmpnam() function need not be thread-safe if  called  with  a  NULL
       parameter.
RETURN VALUE
       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.  Subse-
       quent  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
       No errors are defined.
       The following sections are informative.
EXAMPLES
   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
       This function only creates pathnames. It is the application's responsi-
       bility 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()  func-
       tions instead of the obsolescent tmpnam() function.
RATIONALE
       None.
FUTURE DIRECTIONS
       The tmpnam() function may be removed in a future version.
SEE ALSO
       fopen(), open(), mkdtemp(), tempnam(), tmpfile(), unlink()
       The Base Definitions volume of POSIX.1-2008, <stdio.h>
COPYRIGHT
       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 Electri-
       cal  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.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013                           TMPNAM(3P)