bash tips

http://samrowe.com/wordpress/advancing-in-the-bash-shell/

Bang dollar-sign

!$ is the "end" of the previous command. Consider the following example: We start by looking for a word in a file

1. $ grep -i joe /some/long/directory/structure/user-lists/list-15

if joe is in that userlist, we want to remove him from it. We can either fire up vi with that long directory tree as the argument, or as simply as

1. $ vi !$

Which bash expands to:

1. $ vi /some/long/directory/structure/user-lists/list-15

grep and regular expression

http://www.thegeekstuff.com/2011/01/advanced-regular-expressions-in-grep-command-with-10-examples-%E2%80%93-part-ii/

http://www.cyberciti.biz/faq/grep-regular-expressions/