os/ossrv/genericopenlibs/cstdlib/LSTDIO/GETCHAR.C
author sl
Tue, 10 Jun 2014 14:32:02 +0200
changeset 1 260cb5ec6c19
permissions -rw-r--r--
Update contrib.
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/* GETCHAR.C
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 * 
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 * Portions Copyright (c) 1990-2006 Nokia Corporation and/or its subsidiary(-ies).
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 * All rights reserved.
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 */
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/*
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 * Copyright (c) 1990 The Regents of the University of California.
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms are permitted
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 * provided that the above copyright notice and this paragraph are
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 * duplicated in all such forms and that any documentation,
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 * advertising materials, and other materials related to such
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 * distribution and use acknowledge that the software was developed
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 * by the University of California, Berkeley.  The name of the
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 * University may not be used to endorse or promote products derived
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 * from this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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 */
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/*
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FUNCTION
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<<getchar>>---read a character (macro)
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INDEX
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	getchar
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INDEX
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	_getchar_r
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ANSI_SYNOPSIS
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	#include <stdio.h>
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	int getchar(void);
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	int _getchar_r(void *<[reent]>);
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TRAD_SYNOPSIS
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	#include <stdio.h>
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	int getchar();
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	int _getchar_r(<[reent]>)
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	char * <[reent]>;
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DESCRIPTION
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<<getchar>> is a macro, defined in <<stdio.h>>.  You can use <<getchar>>
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to get the next single character from the standard input stream.
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As a side effect, <<getchar>> advances the standard input's
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current position indicator.
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The alternate function <<_getchar_r>> is a reentrant version.  The
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extra argument <[reent]> is a pointer to a reentrancy structure.
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RETURNS
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The next character (read as an <<unsigned char>>, and cast to
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<<int>>), unless there is no more data, or the host system reports a
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read error; in either of these situations, <<getchar>> returns <<EOF>>.
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You can distinguish the two situations that cause an <<EOF>> result by
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using `<<ferror(stdin)>>' and `<<feof(stdin)>>'.
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PORTABILITY
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ANSI C requires <<getchar>>; it suggests, but does not require, that
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<<getchar>> be implemented as a macro.
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Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
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<<lseek>>, <<read>>, <<sbrk>>, <<write>>.
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*/
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/*
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 * A subroutine version of the macro getchar.
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 */
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#include <stdio_r.h>
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#include <reent.h>
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#undef getchar
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/**
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A reentrant version of getchar().
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*/
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EXPORT_C int
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_getchar_r (struct _reent *f)
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{
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  return getc (_stdin_r (f));
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}
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#ifndef _REENT_ONLY
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/**
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Get the next character from stdin.Returns the next character from the
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standard input.
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@return On Success, the character read is returned as an int. 
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		On Failure, returns EOF, if the 'End Of File' is reached or there has
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		been an error reading and errno may be set.
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*/
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EXPORT_C int
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getchar (void)
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{
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  /* CHECK_INIT is called (eventually) by __srefill.  */
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  struct _reent *r = _REENT2;
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  if (!r)
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	return EOF; // Memory for library globals is not allocated (errno not set).
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  return _getchar_r (r);
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}
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#endif