incubator-nuttx/libs/libc/stdlib/lib_unlockpt.c

61 lines
2.2 KiB
C

/****************************************************************************
* libs/libc/stdlib/lib_unlockpt.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/ioctl.h>
#include <stdlib.h>
#ifdef CONFIG_PSEUDOTERM
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: unlockpt
*
* Description:
* The unlockpt() function unlocks the slave pseudoterminal device
* corresponding to the master pseudoterminal referred to by fd.
* unlockpt() must be called before opening the slave side of a
* pseudoterminal.
*
* Returned Value:
* When successful, unlockpt() returns 0. Otherwise, it returns -1 and
* sets errno appropriately.
*
* EBADF - The fd argument is not a file descriptor open for writing.
* EINVAL - The fd argument is not associated with a master
* pseudoterminal
*
****************************************************************************/
int unlockpt(int fd)
{
return ioctl(fd, TIOCSPTLCK, 0);
}
#endif /* CONFIG_PSEUDOTERM */