update CLib

git-svn-id: svn://kolibrios.org@614 a494cfbc-eb01-0410-851d-a64ba20cac60

programs/develop/open watcom/trunk/clib/streamio/fread.c

@@ -0,0 +1,165 @@
+/****************************************************************************
+*
+*                            Open Watcom Project
+*
+*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
+*
+*  ========================================================================
+*
+*    This file contains Original Code and/or Modifications of Original
+*    Code as defined in and that are subject to the Sybase Open Watcom
+*    Public License version 1.0 (the 'License'). You may not use this file
+*    except in compliance with the License. BY USING THIS FILE YOU AGREE TO
+*    ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
+*    provided with the Original Code and Modifications, and is also
+*    available at www.sybase.com/developer/opensource.
+*
+*    The Original Code and all software distributed under the License are
+*    distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+*    EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
+*    ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
+*    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
+*    NON-INFRINGEMENT. Please see the License for the specific language
+*    governing rights and limitations under the License.
+*
+*  ========================================================================
+*
+* Description:  Implementation of fread() - read data from stream.
+*
+****************************************************************************/
+
+
+#include "variety.h"
+#include <stdio.h>
+#include <unistd.h>
+#include "fileacc.h"
+#include <string.h>
+#include <errno.h>
+#include "rtdata.h"
+#include "seterrno.h"
+#include "qread.h"
+#include "streamio.h"
+
+
+#define DOS_EOF_CHAR    0x1a
+
+extern int  __fill_buffer( FILE * );    /* located in fgetc */
+
+
+_WCRTLINK size_t fread( void *_buf, size_t size, size_t n, FILE *fp )
+{
+    char    *buf = _buf;
+    size_t  len_read;
+
+    _ValidFile( fp, 0 );
+    _AccessFile( fp );
+    if( (fp->_flag & _READ) == 0 ) {
+        __set_errno( EBADF );
+        fp->_flag |= _SFERR;
+        _ReleaseFile( fp );
+        return( 0 );
+    }
+
+#if 0
+    /*** If the buffer is _DIRTY, resync it before reading ***/
+    if( fp->_flag & (_WRITE | _UNGET) ) {
+        if( fp->_flag & _DIRTY ) {
+            fseek( fp, 0, SEEK_CUR );
+        }
+    }
+#endif
+
+    n *= size;
+    if( n == 0 ) {
+        _ReleaseFile( fp );
+        return( n );
+    }
+    if( _FP_BASE(fp) == NULL ) {
+        __ioalloc( fp );                        /* allocate buffer */
+    }
+    len_read = 0;
+#if !defined( __UNIX__ )
+    if( fp->_flag & _BINARY )
+#endif
+    {
+        size_t bytes_left = n, bytes;
+        for( ;; ) {
+            if( fp->_cnt != 0 ) {
+                bytes = fp->_cnt;
+                if( bytes > bytes_left ) {
+                    bytes = bytes_left;
+                }
+                memcpy( buf, fp->_ptr, bytes );
+                fp->_ptr += bytes;
+                buf += bytes;
+                fp->_cnt -= bytes;
+                bytes_left -= bytes;
+                len_read += bytes;
+            }
+            if( bytes_left == 0 ) break;
+
+            /* if user's buffer is larger than our buffer, OR
+               _IONBF is set, then read directly into user's buffer. */
+
+            if( (bytes_left >= fp->_bufsize) || (fp->_flag & _IONBF) ) {
+                bytes = bytes_left;
+                fp->_ptr = _FP_BASE(fp);
+                fp->_cnt = 0;
+                if( !(fp->_flag & _IONBF) ) {
+                    /* if more than a sector, set to multiple of sector size*/
+                    if( bytes > 512 ) {
+                        bytes &= -512;
+                    }
+                }
+                n = __qread( fileno(fp), buf, bytes );
+                if( n == -1 ) {
+                    fp->_flag |= _SFERR;
+                    break;
+                } else if( n == 0 ) {
+                    fp->_flag |= _EOF;
+                    break;
+                }
+                buf += n;
+                bytes_left -= n;
+                len_read += n;
+            } else {
+                if( __fill_buffer( fp ) == 0 )  break;
+            }
+        } /* end for */
+#if !defined(__UNIX__)
+    } else {
+        for( ;; ) {
+            int c;
+
+            // ensure non-empty buffer
+            if( fp->_cnt == 0 ) {
+                if( __fill_buffer( fp ) == 0 ) break;
+            }
+            // get character
+            --fp->_cnt;
+            c = *fp->_ptr++ & 0xff;
+            // perform new-line translation
+            if( c == '\r' ) {
+                // ensure non-empty buffer
+                if( fp->_cnt == 0 ) {
+                    if( __fill_buffer( fp ) == 0 ) break;
+                }
+                // get character
+                --fp->_cnt;
+                c = *fp->_ptr++ & 0xff;
+            }
+            // check for DOS end of file marker
+            if( c == DOS_EOF_CHAR ) {
+                fp->_flag |= _EOF;
+                break;
+            }
+            // store chracter
+            buf[len_read] = (char)c;
+            ++len_read;
+            if( len_read == n ) break;
+        }
+#endif
+    }
+    _ReleaseFile( fp );
+    return( len_read / size );
+}