How to clear the screen in C++?

Question

How to clear the screen in C++ ? I already put the library: ** #include< stdlib. h>** and the code: system("cls"), but gives the error: "sh: 1: cls: not found". How do I fix this?

Answer 1

Deleting the screen is an operation dependent on the environment in which the program operates. For example, a graphical program does not even have this operation, because it is not running in a terminal.

That being said, it looks like you are running the program in a UNIX/Linux environment, so I suggest replacing "cls" with "clear", because "cls" is the MS-DOS/Windows command line instruction to clear the screen.

Answer 2

As already said, it depends on the environment, however as suggested I already fear the command:

clear

Which is usually used on Unix-like systems (linux for example) and the command:

cls

Used on Windows systems.

If the error occurs it may be because it is running cls on a Linux system (or similar).

To create a 'certain compatibility' between different systems can be a little complex, there are those who suggest using the compiler definitions, for example (is a very simple example):

#if defined(_WIN32) || defined(_WIN64)
    system("cls");
#else defined(__linux__) || defined(__unix__)
    system("clear");
#endif

But this of course may vary a lot for each compiler, or maybe the available compilers or libs use other definitions to identify the system that was compiled, so a suggestion that I think would be more guaranteed would be to use in the command itself the || and with this pass both commands (cls and clear), for example:

system("clear||cls");

The above command will execute like this, first it tries to execute the clear, if it is a command available in the user’s system then it will run, otherwise it will try to run cls.

This can make your program a little more "portable" between different systems without worrying so much about different types of compilers.