incubator-nuttx/libs/libc/termios/lib_isatty.c

58 lines
2.2 KiB
C

/****************************************************************************
* libs/libc/termios/lib_isatty.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.
*
****************************************************************************/
/* Source:
* https://github.com/raggi/apue.2e/blob/master/termios/isatty.c
* based on Advanced Programming in the UNIX Environment
*/
/****************************************************************************
* Included Files
****************************************************************************/
#include <termios.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: isatty
*
* Description:
* Return a non-zero (true) value if the file descriptor, fd, corresponds
* to a TTYY.
*
* NOTE: NuttX, of course, does not have true TTYs in the sense that this
* function is intended. In this implementation, the function simply
* returns true if the file descriptor is associated with a driver that
* responds wo tcgetattr() without an error -- that it, the driver supports
* the NuttX TCGETS ioctl command.
*
* Of course, that can only be true if CONFIG_SERIAL_TERMIOS=y.
*
****************************************************************************/
int isatty(int fd)
{
struct termios ts;
return (tcgetattr(fd, &ts) >= 0);
}