usr/src/lib/libc/port/stdio/__extensions.c

   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 }