Grep is really a Grip

Grep stands for Global (Search for) Regular Expression and Print.
It is a unix command used for a pattern matching
in files . We can find a line in a file which matches some phraces
effectively using this command. We can find more about its usage
by reading its man pages.
for example to find a user who has no password can be found
by using
$ grep '^[^:]*::' /etc/passwd
Cool na ?
Also there are so much cooL commands in unix we have to be familiar
like "sed","awk"...
we can see those on the way.