GETC(3)                    POSIX Programmer's Manual                   GETC(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
       getc -- get a byte from a stream

SSYYNNOOPPSSIISS
       #include <stdio.h>

       int getc(FILE *_s_t_r_e_a_m);

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.1-2008
       defers to the ISO C standard.

       The _g_e_t_c() function shall be equivalent to _f_g_e_t_c(), except that if it
       is implemented as a macro it may evaluate _s_t_r_e_a_m more than once, so the
       argument should never be an expression with side-effects.

RREETTUURRNN VVAALLUUEE
       Refer to _f_g_e_t_c().

EERRRROORRSS
       Refer to _f_g_e_t_c().

       _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
       None.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       If the integer value returned by _g_e_t_c() is stored into a variable of
       type cchhaarr and then compared against the integer constant EOF, the
       comparison may never succeed, because sign-extension of a variable of
       type cchhaarr on widening to integer is implementation-defined.

       Since it may be implemented as a macro, _g_e_t_c() may treat incorrectly a
       _s_t_r_e_a_m argument with side-effects. In particular, _g_e_t_c(*_f++) does not
       necessarily work as expected. Therefore, use of this function should be
       preceded by ""##uunnddeeffgetc" in such situations; _f_g_e_t_c() could also be
       used.

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_g_e_t_c()

       The Base Definitions volume of POSIX.1-2008, <<ssttddiioo..hh>>

CCOOPPYYRRIIGGHHTT
       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                              GETC(3)
