incubator-nuttx/libs/libc/stdio/lib_gets_s.c

81 lines
3.0 KiB
C

/****************************************************************************
* libs/libc/stdio/lib_gets_s.c
*
* SPDX-License-Identifier: Apache-2.0
*
* 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 <stdio.h>
#include <stdint.h>
#include <unistd.h>
#include "libc.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: gets
*
* Description:
* gets() reads a line from stdin into the buffer pointed to by s until
* either a terminating newline or EOF, which it replaces with '\0'. Reads
* at most n-1 characters from stdin into the array pointed to by str until
* new-line character, end-of-file condition, or read error. The newline
* character, if encountered, is not saved in the array. A NUL character
* is written immediately after the last character read into the array, or
* to str[0] if no characters were read.
*
* If n is zero or is greater than RSIZE_MAX, a null character is written
* to str[0] but the function reads and discards characters from stdin
* until new-line character, end-of-file condition, or read error (not
* implemented).
*
* If n-1 characters have been read, continues reading and discarding the
* characters from stdin until new-line character, end-of-file condition,
* or read error.
*
****************************************************************************/
FAR char *gets_s(FAR char *s, rsize_t n)
{
/* Handle the case where n is out of range as required */
if (n < 1 || n > RSIZE_MAX)
{
/* Set n=1, i.e., room only for the NUL terminator */
n = 1;
}
/* Then let lib_fgets() do the heavy lifting */
#ifdef CONFIG_FILE_STREAM
return lib_fgets(s, n, stdin, false, true);
#else
return lib_dgets(s, n, STDIN_FILENO, false, true);
#endif
}