$ cheat grep
# Basic:
grep pattern file
 
# case nonsensitive research:
grep -i pattern file
 
# Recursively grep for string <pattern> in folder:
grep -R pattern folder
 
# Getting pattern from file (one by line):
grep -f pattern_file file
 
# Find lines NOT containing pattern
grep -v pattern file
 
# You can grep with regular expressions
grep "^00" file  #Match lines starting with 00
grep -E "[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}" file  #Find IP add
 
# Find all files who contain {pattern} in the directory {directory}.
# This will show: "file:line my research"
grep -rnw 'directory' -e "pattern"
 
# Exclude grep from your grepped output of ps.
# Add [] to the first letter. Ex: sshd -> [s]shd
ps aux | grep '[h]ttpd
 
 
 
## grep's -A 1 option will give you one line after; -B 1 will give you one line before; and -C 1 combines both to give you one line both before and after.