kolibrios/programs/develop/libraries/newlib/reent/readr.c
Sergey Semyonov (Serge) 0a3f4b2193 Newlib source code
git-svn-id: svn://kolibrios.org@1693 a494cfbc-eb01-0410-851d-a64ba20cac60
2010-11-07 13:42:29 +00:00

169 lines
4.0 KiB
C

/* Reentrant versions of read system call. */
#include <reent.h>
#include <unistd.h>
#include <_syslist.h>
#include <errno.h>
/* Some targets provides their own versions of this functions. Those
targets should define REENTRANT_SYSCALLS_PROVIDED in TARGET_CFLAGS. */
#ifdef _REENT_ONLY
#ifndef REENTRANT_SYSCALLS_PROVIDED
#define REENTRANT_SYSCALLS_PROVIDED
#endif
#endif
#ifndef REENTRANT_SYSCALLS_PROVIDED
/* We use the errno variable used by the system dependent layer. */
/*
FUNCTION
<<_read_r>>---Reentrant version of read
INDEX
_read_r
ANSI_SYNOPSIS
#include <reent.h>
_ssize_t _read_r(struct _reent *<[ptr]>,
int <[fd]>, void *<[buf]>, size_t <[cnt]>);
TRAD_SYNOPSIS
#include <reent.h>
_ssize_t _read_r(<[ptr]>, <[fd]>, <[buf]>, <[cnt]>)
struct _reent *<[ptr]>;
int <[fd]>;
char *<[buf]>;
size_t <[cnt]>;
DESCRIPTION
This is a reentrant version of <<read>>. It
takes a pointer to the global data block, which holds
<<errno>>.
*/
extern unsigned __NFiles;
#define _READ 0x0001 /* file opened for reading */
#define _BINARY 0x0040 /* file is binary, skip CRLF processing */
#define _ISTTY 0x2000 /* is console device */
#define __handle_check( __h, __r ) \
if( (__h) < 0 || (__h) > __NFiles ) { \
ptr->_errno = EBADF; \
return( __r ); \
}
_ssize_t
_DEFUN (_read, (fd, buf, cnt),
int fd _AND
_PTR buf _AND
size_t cnt)
{
return _read_r( _REENT, fd, buf, cnt);
}
_ssize_t
_DEFUN (_read_r, (ptr, fd, buf, cnt),
struct _reent *ptr _AND
int fd _AND
_PTR buf _AND
size_t cnt)
{
_ssize_t ret;
_ssize_t read_len, total_len;
unsigned reduce_idx, finish_idx;
unsigned iomode_flags;
char *buffer = buf;
int rc;
int h;
unsigned amount_read;
int err;
__file_handle *fh;
__handle_check( fd, -1 );
__ChkTTYIOMode( fd );
iomode_flags = __GetIOMode( fd );
if( iomode_flags == 0 )
{
ptr->_errno = EBADF;
return( -1 );
}
if( !(iomode_flags & _READ) )
{
ptr->_errno = EACCES; /* changed from EBADF to EACCES 23-feb-89 */
return( -1 );
}
fh = (__file_handle*) __getOSHandle( fd );
if( iomode_flags & _BINARY ) /* if binary mode */
{
err = read_file(fh->name, buffer, fh->offset, cnt, &amount_read);
fh->offset+= amount_read;
total_len = amount_read;
if(err)
if ( amount_read == 0)
return (-1);
}
else
{
total_len = 0;
read_len = cnt;
do
{
err=read_file(fh->name,buffer, fh->offset, cnt, &amount_read);
fh->offset+=amount_read;
if( amount_read == 0 )
break; /* EOF */
reduce_idx = 0;
finish_idx = reduce_idx;
for( ; reduce_idx < amount_read; ++reduce_idx )
{
if( buffer[ reduce_idx ] == 0x1a ) /* EOF */
{
_lseek_r(ptr, fd, ((long)reduce_idx - (long)amount_read)+1L,
SEEK_CUR );
total_len += finish_idx;
return( total_len );
}
if( buffer[ reduce_idx ] != '\r' )
{
buffer[ finish_idx++ ] = buffer[ reduce_idx ];
};
}
total_len += finish_idx;
buffer += finish_idx;
read_len -= finish_idx;
if( iomode_flags & _ISTTY )
{
break; /* 04-feb-88, FWC */
}
} while( read_len != 0 );
}
return( total_len );
}
_ssize_t
_DEFUN (read, (fd, buf, cnt),
int fd _AND
_PTR buf _AND
size_t cnt)
{
return _read_r(_REENT, fd, buf, cnt);
};
#endif /* ! defined (REENTRANT_SYSCALLS_PROVIDED) */