FILE* inputFile;

const char * file_in;

if ((inputFile = fopen(file_in, "r")) == NULL)     //读取输入文件

{

printf("\nerror: 无法打开输入文件: %s\n\n", file_in);

std::cerr << "Parser: could not open input file '" << file_in << "'!\n";

return EXIT_FAILURE;

}

但若在 Visual Studio 下, 会提示 fopen 不安全, 建议使用 fopen_s.

//Declaring a variable of type errno_t to store the return value of fopen_s

    errno_t error_code1; 

    //Opening file in r mode

    error_code1 = fopen_s(&inputFile, file_in, "r");

    if (error_code1 != 0) {

        printf("Error! Failed to open file %s in r mode!", file_in);

    }