TMPNAM(3)                  POSIX Programmer's Manual                 TMPNAM(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
       tmpnam -- create a name for a temporary file

SSYYNNOOPPSSIISS
       #include <stdio.h>

       char *tmpnam(char *_s);

DDEESSCCRRIIPPTTIIOONN
       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.1-2017
       defers to the ISO C standard.

       The _t_m_p_n_a_m() 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 _t_m_p_n_a_m() 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.1-2017, except _t_e_m_p_n_a_m(), calls _t_m_p_n_a_m().

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

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

       If the argument _s is a null pointer, _t_m_p_n_a_m() shall leave its result in
       an internal static object and return a pointer to that object.
       Subsequent calls to _t_m_p_n_a_m() 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 cchhaarrs; _t_m_p_n_a_m() shall write its result in that
       array and shall return the argument as its value.

EERRRROORRSS
       No errors are defined.

       _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 unique pathname and stores it in the
       array pointed to by _p_t_r.


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

           ptr = tmpnam(pathname);

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_s_t_e_m_p(), or _m_k_d_t_e_m_p()
       functions instead of the obsolescent _t_m_p_n_a_m() function.

RRAATTIIOONNAALLEE
       None.

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

SSEEEE AALLSSOO
       _f_o_p_e_n(), _o_p_e_n(), _m_k_d_t_e_m_p(), _t_e_m_p_n_a_m(), _t_m_p_f_i_l_e(), _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                            TMPNAM(3)
