diff options
Diffstat (limited to '')
-rw-r--r-- | cpukit/libcsupport/src/lseek.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/cpukit/libcsupport/src/lseek.c b/cpukit/libcsupport/src/lseek.c new file mode 100644 index 0000000000..514f8cd912 --- /dev/null +++ b/cpukit/libcsupport/src/lseek.c @@ -0,0 +1,93 @@ +/* + * lseek() - POSIX 1003.1b 6.5.3 - Reposition Read/Write File Offset + * + * COPYRIGHT (c) 1989-1998. + * On-Line Applications Research Corporation (OAR). + * Copyright assigned to U.S. Government, 1994. + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.OARcorp.com/rtems/license.html. + * + * $Id$ + */ + +#include <stdio.h> + +#include "libio_.h" + +off_t lseek( + int fd, + off_t offset, + int whence +) +{ + rtems_libio_t *iop; + + /* + * If this file descriptor is mapped to an external set of handlers, + * then pass the request on to them. + */ + + if ( rtems_file_descriptor_type( fd ) ) { + rtems_libio_lseek_t fp; + + fp = rtems_libio_handlers[rtems_file_descriptor_type_index(fd)].lseek; + if ( fp == NULL ) + set_errno_and_return_minus_one( EBADF ); + + return (*fp)( fd, offset, whence ); + } + + /* + * Now process the lseek(). + */ + + iop = rtems_libio_iop( fd ); + rtems_libio_check_fd( fd ); + + switch ( whence ) { + case SEEK_SET: + iop->offset = offset; + break; + + case SEEK_CUR: + iop->offset += offset; + break; + + case SEEK_END: + iop->offset = iop->size - offset; + break; + + default: + errno = EINVAL; + return -1; + } + + if ( !iop->handlers->lseek ) + set_errno_and_return_minus_one( ENOTSUP ); + + return (*iop->handlers->lseek)( iop, offset, whence ); +} + +/* + * _lseek_r + * + * This is the Newlib dependent reentrant version of lseek(). + */ + +#if defined(RTEMS_NEWLIB) + +#include <reent.h> + +off_t _lseek_r( + struct _reent *ptr, + int fd, + off_t offset, + int whence +) +{ + return lseek( fd, offset, whence ); +} +#endif + |