Showing posts with label egrep. Show all posts
Showing posts with label egrep. Show all posts

Tuesday, September 09, 2008

grep based on multiple words

For example, grep "you" and "me" in the file,

grep "you\|me" filename

You need to put ESCAPE STRING ( \ ) for OR ( | ), else it will treat it as a simbol you want to search instead of regular expression symbol. or

grep -E "you|me" filename

or

egrep "you|me" filename

But, to get line with both "you" and "me", you can use

grep "you" filename | grep "me"

or, 

egrep "you.*me" filename

but this will include those lines like "your lovely meebo", which is not what we want sometime. So, to get the exact words matched, use

egrep "\.*\" filename

For more info about egrep, use "man egrep"

The caret ^ and the dollar sign $ are metacharacters that respectively match the  empty  string  at  the beginning and end of a line.  The symbols \<> respectively match the empty string at the beginning  and end of a word.  The symbol \b matches the empty string at the edge of a word,  and  \B  matches  the  empty string provided it not at the edge of a word.