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Diffstat (limited to '')
-rw-r--r-- | c/src/lib/libc/read.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/c/src/lib/libc/read.c b/c/src/lib/libc/read.c new file mode 100644 index 0000000000..150fe675ab --- /dev/null +++ b/c/src/lib/libc/read.c @@ -0,0 +1,84 @@ +/* + * read() - POSIX 1003.1b 6.4.1 - Read From a File + * + * 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 "libio_.h" + +/* XXX newlib has the prototype for this wrong. It will be a bit painful */ +/* XXX to fix so we are choosing to delay fixing this. */ + +int read( + int fd, + void *buffer, + unsigned32 count +) +{ + int rc; /* XXX change to a size_t when prototype is fixed */ + 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_read_t fp; + + fp = rtems_libio_handlers[rtems_file_descriptor_type_index(fd)].read; + if ( fp == NULL ) + set_errno_and_return_minus_one( EBADF ); + + return (*fp)( fd, buffer, count ); + } + + /* + * Now process the read(). + */ + + iop = rtems_libio_iop( fd ); + rtems_libio_check_fd( fd ); + rtems_libio_check_buffer( buffer ); + rtems_libio_check_count( count ); + rtems_libio_check_permissions( iop, LIBIO_FLAGS_READ ); + + if ( !iop->handlers->read ) + set_errno_and_return_minus_one( ENOTSUP ); + + rc = (*iop->handlers->read)( iop, buffer, count ); + + if ( rc > 0 ) + iop->offset += rc; + + return rc; +} + +/* + * _read_r + * + * This is the Newlib dependent reentrant version of read(). + */ + +#if defined(RTEMS_NEWLIB) + +#include <reent.h> + +_ssize_t _read_r( + struct _reent *ptr, + int fd, + void *buf, + size_t nbytes +) +{ + return read( fd, buf, nbytes ); +} +#endif |