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GETC(3P)                   POSIX Programmer's Manual                  GETC(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
       getc -- get a byte from a stream
SYNOPSIS
       #include <stdio.h>
       int getc(FILE *stream);
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  getc()  function shall be equivalent to fgetc(), except that if it
       is implemented as a macro it may evaluate stream more than once, so the
       argument should never be an expression with side-effects.
RETURN VALUE
       Refer to fgetc().
ERRORS
       Refer to fgetc().
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       If  the  integer  value returned by getc() is stored into a variable of
       type char and then compared against the integer constant EOF, the  com-
       parison may never succeed, because sign-extension of a variable of type
       char on widening to integer is implementation-defined.
       Since it may be implemented as a macro, getc() may treat incorrectly  a
       stream  argument  with side-effects. In particular, getc(*f++) does not
       necessarily work as expected. Therefore, use of this function should be
       preceded  by  "#undefgetc"  in  such  situations; fgetc() could also be
       used.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       Section 2.5, Standard I/O Streams, fgetc()
       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                             GETC(3P)