TMPFILE(3)                 POSIX Programmer's Manual                TMPFILE(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
       tmpfile -- create a temporary file

SSYYNNOOPPSSIISS
       #include <stdio.h>

       FILE *tmpfile(void);

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_f_i_l_e() 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 shall be opened as in
       _f_o_p_e_n() for update (_w_b+), 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 _t_m_p_f_i_l_e() is killed while it is processing a call to
       _t_m_p_f_i_l_e().

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

RREETTUURRNN VVAALLUUEE
       Upon successful completion, _t_m_p_f_i_l_e() shall return a pointer to the
       stream of the file that is created.  Otherwise, it shall return a null
       pointer and set _e_r_r_n_o to indicate the error.

EERRRROORRSS
       The _t_m_p_f_i_l_e() function shall fail if:

       EEIINNTTRR  A signal was caught during _t_m_p_f_i_l_e().

       EEMMFFIILLEE All file descriptors available to the process are currently
              open.

       EEMMFFIILLEE {STREAM_MAX} streams are currently open in the calling process.

       EENNFFIILLEE The maximum allowable number of files is currently open in the
              system.

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

       EEOOVVEERRFFLLOOWW
              The file is a regular file and the size of the file cannot be
              represented correctly in an object of type ooffff__tt.

       The _t_m_p_f_i_l_e() function may fail if:

       EEMMFFIILLEE {FOPEN_MAX} streams are currently open in the calling process.

       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
   CCrreeaattiinngg aa TTeemmppoorraarryy FFiillee
       The following example creates a temporary file for update, and returns
       a pointer to a stream for the created file in the _f_p variable.


           #include <stdio.h>
           ...
           FILE *fp;

           fp = tmpfile ();

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       It should be possible to open at least {TMP_MAX} temporary files during
       the lifetime of the program (this limit may be shared with _t_m_p_n_a_m())
       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}).

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _S_e_c_t_i_o_n _2_._5, _S_t_a_n_d_a_r_d _I_/_O _S_t_r_e_a_m_s, _f_o_p_e_n(), _m_k_d_t_e_m_p(), _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                           TMPFILE(3)
