System. Function int system (const char* command); Execute system command Invokes the command processor to execute a .
If is a null pointer, the function only checks whether a command processor is available through this function, without invoking any command. Stdout. The standard output stream is the default destination of output for applications.
In most systems, it is usually directed by default to the text console (generally, on the screen). stdout can be used as an argument for any function that takes an argument of type FILE* expecting an output stream, like fputs or fprintf. Stdin. The standard input stream is the default source of data for applications.
In most systems, it is usually directed by default to the keyboard. stdin can be used as an argument for any function that expects an input stream (FILE*) as one of its parameters, like fgets or fscanf. Although it is commonly assumed that the source of data for stdin is going to be a keyboard, this may not be the case even in regular console systems, since stdin can generally be redirected on most operating systems at the time of invoking the application. For example, many systems, among them DOS/Windows and most UNIX shells, support the following command syntax: C++ Reference [C++ Reference]