Re^3: Slicing the output of a command

Why cat the whole file just to discard all but the first four lines:

my @foo = `head -4 very_large_file`;
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Re^4: Slicing the output of a command by marioroy (Prior) on Jul 10, 2015 at 04:00 UTC
+1 BrowserUk. I'm not sure if the behavior is the same in Windows, but the 'cat command' receives a PIPE signal and exits once count lines have been read by the 'head command'.	[reply]
Re^5: Slicing the output of a command by afoken (Chancellor) on Jul 10, 2015 at 10:21 UTC
Windows has no signals, so no SIGPIPE there. Alexander -- Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)	[reply]
Re^6: Slicing the output of a command by BrowserUk (Patriarch) on Jul 10, 2015 at 11:17 UTC
You're correct, however, marioroy's point holds. When head has read its 4 lines it closes the pipe and effectively prevents cat (or type or copy etc.) from reading further. (That doesn't stop it from be a Useless use of cat though.)	[reply]