1 /* GETCHAR.C

     2  * 

     3  * Portions Copyright (c) 1990-2006 Nokia Corporation and/or its subsidiary(-ies).

     4  * All rights reserved.

     5  */

     6 

     7 /*

     8  * Copyright (c) 1990 The Regents of the University of California.

     9  * All rights reserved.

    10  *

    11  * Redistribution and use in source and binary forms are permitted

    12  * provided that the above copyright notice and this paragraph are

    13  * duplicated in all such forms and that any documentation,

    14  * advertising materials, and other materials related to such

    15  * distribution and use acknowledge that the software was developed

    16  * by the University of California, Berkeley.  The name of the

    17  * University may not be used to endorse or promote products derived

    18  * from this software without specific prior written permission.

    19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR

    20  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED

    21  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

    22  */

    23 

    24 /*

    25 FUNCTION

    26 <<getchar>>---read a character (macro)

    27 

    28 INDEX

    29 	getchar

    30 INDEX

    31 	_getchar_r

    32 

    33 ANSI_SYNOPSIS

    34 	#include <stdio.h>

    35 	int getchar(void);

    36 

    37 	int _getchar_r(void *<[reent]>);

    38 

    39 TRAD_SYNOPSIS

    40 	#include <stdio.h>

    41 	int getchar();

    42 

    43 	int _getchar_r(<[reent]>)

    44 	char * <[reent]>;

    45 

    46 DESCRIPTION

    47 <<getchar>> is a macro, defined in <<stdio.h>>.  You can use <<getchar>>

    48 to get the next single character from the standard input stream.

    49 As a side effect, <<getchar>> advances the standard input's

    50 current position indicator.

    51 

    52 The alternate function <<_getchar_r>> is a reentrant version.  The

    53 extra argument <[reent]> is a pointer to a reentrancy structure.

    54 

    55 

    56 RETURNS

    57 The next character (read as an <<unsigned char>>, and cast to

    58 <<int>>), unless there is no more data, or the host system reports a

    59 read error; in either of these situations, <<getchar>> returns <<EOF>>.

    60 

    61 You can distinguish the two situations that cause an <<EOF>> result by

    62 using `<<ferror(stdin)>>' and `<<feof(stdin)>>'.

    63 

    64 PORTABILITY

    65 ANSI C requires <<getchar>>; it suggests, but does not require, that

    66 <<getchar>> be implemented as a macro.

    67 

    68 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,

    69 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.

    70 */

    71 

    72 /*

    73  * A subroutine version of the macro getchar.

    74  */

    75 

    76 #include <stdio_r.h>

    77 #include <reent.h>

    78 

    79 #undef getchar

    80 

    81 /**

    82 A reentrant version of getchar().

    83 */

    84 EXPORT_C int

    85 _getchar_r (struct _reent *f)

    86 {

    87   return getc (_stdin_r (f));

    88 }

    89 

    90 #ifndef _REENT_ONLY

    91 

    92 /**

    93 Get the next character from stdin.Returns the next character from the

    94 standard input.

    95 

    96 @return On Success, the character read is returned as an int. 

    97 		On Failure, returns EOF, if the 'End Of File' is reached or there has

    98 		been an error reading and errno may be set.

    99 */

   100 EXPORT_C int

   101 getchar (void)

   102 {

   103   /* CHECK_INIT is called (eventually) by __srefill.  */

   104   struct _reent *r = _REENT2;

   105   if (!r)

   106 	return EOF; // Memory for library globals is not allocated (errno not set).

   107   return _getchar_r (r);

   108 }

   109 

   110 #endif