Recently I got to know of -- that is double-hyphen which is used to tell a command that the option list has ended and what follows should not be considered as a option. So,
grep -- 'search_word' *
would search for the given search_word. But you could see a unexpected behavior if you remove -- and if there is a single file that start with -, which would switch on the option that match with the chars in filename.
What is this -- called ? Is there any technical term to this ?
The -- is working for tools which use getopt(3) to process command line arguments and many API that parse POSIX style options.
From the manual page of getopt(3):
The interpretation of options in the argument list may be cancelled by the option `--' (double dash) which causes getopt() to signal the end of argument processing and return -1.
I would then say it is called double dash
echo and [ support it
– Stéphane Chazelas
Nov 22 '12 at 14:30
The only two names which I've head in practise are "double dash" for referring to it aesthetically, and "end of options" for referring to it functionally.
cd --andcd -phenomena. whilecd --means essentially justcdand thus change into your$HOME,cd -means put your self into previous directory. This becomes handy when you wanted tocd ..but as with german keyboard layout I mix it often up withcd --.cd -will then put you back. :D – math Sep 24 '13 at 07:33