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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 
     22 /*
     23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     28 
     29 #include "lint.h"
     30 #include "file64.h"
     31 #include <sys/types.h>
     32 #include <stdio.h>
     33 #include <mtlib.h>
     34 #include "stdiom.h"
     35 #include <stdio_ext.h>
     36 
     37 /*
     38  * Returns non-zero if the file is open readonly, or if the last operation
     39  * on the stream was a read e.g. fread() or fgetc().  Otherwise returns 0.
     40  */
     41 int
     42 __freading(FILE *stream)
     43 {
     44 	return (stream->_flag & _IOREAD);
     45 }
     46 
     47 /*
     48  * Returns non-zero if the file is open write-only or append-only, or if
     49  * the last operation on the stream was a write e.g. fwrite() or fputc().
     50  * Otherwise returns 0.
     51  */
     52 int
     53 __fwriting(FILE *stream)
     54 {
     55 	return (stream->_flag & _IOWRT);
     56 }
     57 
     58 /*
     59  * Returns non-zero if it is possible to read from a stream.
     60  */
     61 int
     62 __freadable(FILE *stream)
     63 {
     64 	return (stream->_flag & (_IOREAD|_IORW));
     65 }
     66 
     67 /*
     68  * Returns non-zero if it is possible to write on a stream.
     69  */
     70 int
     71 __fwritable(FILE *stream)
     72 {
     73 	return (stream->_flag & (_IOWRT|_IORW));
     74 }
     75 
     76 /*
     77  * Returns non-zero if the stream is line buffered.
     78  */
     79 int
     80 __flbf(FILE *stream)
     81 {
     82 	return (stream->_flag & _IOLBF);
     83 }
     84 
     85 /*
     86  * Discard any pending buffered I/O.
     87  */
     88 void
     89 __fpurge(FILE *stream)
     90 {
     91 	rmutex_t *lk;
     92 
     93 	FLOCKFILE(lk, stream);
     94 	if ((stream->_ptr = stream->_base) != NULL)
     95 		stream->_cnt = 0;
     96 	FUNLOCKFILE(lk);
     97 }
     98 
     99 /*
    100  * Return the amount of output pending on a stream (in bytes).
    101  */
    102 size_t
    103 __fpending(FILE *stream)
    104 {
    105 	size_t amount;
    106 	rmutex_t *lk;
    107 
    108 	FLOCKFILE(lk, stream);
    109 	amount = stream->_ptr - stream->_base;
    110 	FUNLOCKFILE(lk);
    111 	return (amount);
    112 }
    113 
    114 /*
    115  * Returns the buffer size (in bytes) currently in use by the given stream.
    116  */
    117 size_t
    118 __fbufsize(FILE *stream)
    119 {
    120 	size_t size;
    121 	rmutex_t *lk;
    122 
    123 	FLOCKFILE(lk, stream);
    124 	size = _bufend(stream) - stream->_base;
    125 	FUNLOCKFILE(lk);
    126 	return (size);
    127 }
    128