c++ - How to check if there is a file input using pipe -

How can I know the command line: ./main or: ./main & lt; Generally you should not take care or care, but if you really need it, you can use it. If something is going to be input from a console (possibly (filename (stdin)) // // is probably getting input from a file,

Neither is a standardized part of isatty or fileno , but both are included in posix (if memory works) and is available most non -Possix system also (like, on Windows, although MS dislikes these names, and advised to use _isatty and _fileno Ete are).