What !! means while calling echo
54998
What does "apt-get install !!" do and how to make it work?
130399
What is the difference between  and !=
47400
How are echo and print different in PHP?
107286
'Call up' - what does 'up' mean?
42711
What does $$ mean in the shell?
154673
In the shell, what does " 2>&1 " mean?
46150
Can't use exclamation mark (!) in bash?
20348
What does the '!' really do when it's added to an ex command (:wq! | :w! | :q! )?
57124
Does echo -e make a difference when quotes are not used?
93920
What does @ mean in PHP?
11975
What does $@ mean in a shell script?
111595
What does this sign exactly mean? |=
153140
What does “” exactly mean in “echo  temp.txt”?
82369
What does #{...} mean?
144095
What do these commands mean?
4772
Difference between "not equal" operators  and != in PHP
23092
What does "$$" mean in the shell?