Pure speculation, but maybe cmd.exe executes a system call to put the screen in ANSI mode, then prints an escape sequence to clear the screen, then executes another syscall to take it out of ANSI mode. Maybe the screen clearing requires both a syscall and something printed, and your program is only doing one.

In reply to Re: Re: Re: The difference between [system] and `backticks` and [qx//] (on win32) by sgifford
in thread The difference between [system] and `backticks` and [qx//] (on win32) by BrowserUk

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