Search
From KevinWiki
Search a String in a File
grep -H "<keyword to search>" <filename>
grep -H "Invalid" /var/log/auth.log
Search a String in a Large Number of Files
for i in `find /<directory to search>/`; do grep -H "<keyword to search>" $i; done
for i in `find /home/user/`; do grep -H "Subject" $i; done