scanf_s.c

/**
 * Copyright 2020 Huawei Technologies Co., Ltd
 *
 * Licensed 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.
 */

#include "securec.h"

/*
 * <FUNCTION DESCRIPTION>
 *    The scanf_s function is equivalent to fscanf_s with the argument stdin interposed before the arguments to scanf_s
 *     The scanf_s function reads data from the standard input stream stdin and
 *    writes the data into the location that's given by argument. Each argument
 *    must be a pointer to a variable of a type that corresponds to a type specifier
 *    in format. If copying occurs between strings that overlap, the behavior is
 *    undefined.
 *
 * <INPUT PARAMETERS>
 *    format                  Format control string.
 *    ...                       Optional arguments.
 *
 * <OUTPUT PARAMETERS>
 *    ...                       The converted value stored in user assigned address
 *
 * <RETURN VALUE>
 *    Returns the number of fields successfully converted and assigned;
 *    the return value does not include fields that were read but not assigned.
 *    A return value of 0 indicates that no fields were assigned.
 *    return -1 if an error occurs.
 */

int scanf_s(const char *format, ...)
{
    int ret;                    /* If initialization causes  e838 */
    va_list argList;

    va_start(argList, format);
    ret = vscanf_s(format, argList);
    va_end(argList);
    (void)argList;              /* to clear e438 last value assigned not used , the compiler will optimize this code */

    return ret;
}