TEMPNAM(3)                 POSIX Programmer's Manual                TEMPNAM(3)



PPRROOLLOOGG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NNAAMMEE
       tempnam -- create a name for a temporary file

SSYYNNOOPPSSIISS
       #include <stdio.h>

       char *tempnam(const char *_d_i_r, const char *_p_f_x);

DDEESSCCRRIIPPTTIIOONN
       The _t_e_m_p_n_a_m() function shall generate a pathname that may be used for a
       temporary file.

       The _t_e_m_p_n_a_m() function allows the user to control the choice of a
       directory. The _d_i_r argument points to the name of the directory in
       which the file is to be created. If _d_i_r is a null pointer or points to
       a string which is not a name for an appropriate directory, the path
       prefix defined as P_tmpdir in the _<_s_t_d_i_o_._h_> header shall be used. If
       that directory is not accessible, an implementation-defined directory
       may be used.

       Many applications prefer their temporary files to have certain initial
       letter sequences in their names. The _p_f_x argument should be used for
       this. This argument may be a null pointer or point to a string of up to
       five bytes to be used as the beginning of the filename.

       Some implementations of _t_e_m_p_n_a_m() may use _t_m_p_n_a_m() internally. On such
       implementations, if called more than {TMP_MAX} times in a single
       process, the behavior is implementation-defined.

RREETTUURRNN VVAALLUUEE
       Upon successful completion, _t_e_m_p_n_a_m() shall allocate space for a
       string, put the generated pathname in that space, and return a pointer
       to it. The pointer shall be suitable for use in a subsequent call to
       _f_r_e_e().  Otherwise, it shall return a null pointer and set _e_r_r_n_o to
       indicate the error.

EERRRROORRSS
       The _t_e_m_p_n_a_m() function shall fail if:

       EENNOOMMEEMM Insufficient storage space is available.

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

EEXXAAMMPPLLEESS
   GGeenneerraattiinngg aa PPaatthhnnaammee
       The following example generates a pathname for a temporary file in
       directory //ttmmpp, with the prefix _f_i_l_e.  After the pathname has been
       created, the call to _f_r_e_e() deallocates the space used to store the
       pathname.


           #include <stdio.h>
           #include <stdlib.h>
           ...
           const char *directory = "/tmp";
           const char *fileprefix = "file";
           char *file;

           file = tempnam(directory, fileprefix);
           free(file);

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       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 _t_m_p_f_i_l_e() more useful.

       Applications should use the _t_m_p_f_i_l_e(), _m_k_d_t_e_m_p(), or _m_k_s_t_e_m_p()
       functions instead of the obsolescent _t_e_m_p_n_a_m() function.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       The _t_e_m_p_n_a_m() function may be removed in a future version.

SSEEEE AALLSSOO
       _f_o_p_e_n(), _f_r_e_e(), _m_k_d_t_e_m_p(), _o_p_e_n(), _t_m_p_f_i_l_e(), _t_m_p_n_a_m(), _u_n_l_i_n_k()

       The Base Definitions volume of POSIX.1-2017, <<ssttddiioo..hh>>

CCOOPPYYRRIIGGHHTT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

       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                  2017                           TEMPNAM(3)
