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 comparison 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  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 .