How can I grep for lines containing foo AND bar, foo OR bar?
The easiest way to match both foo AND bar is to use two grep commands:
grep foo | grep bar
It can also be done with one egrep, although (as you can probably guess) this doesn't really scale well to more than two patterns:
egrep 'foo.*bar|bar.*foo'
If you prefer, you can achieve this in one sed or awk statement. (The awk example is probably the most scalable.)
sed -n '/foo/{/bar/p}'
awk '/foo/ && /bar/'To match lines containing foo OR bar, egrep is the natural choice, but it can also be done with sed, awk, etc.
egrep 'foo|bar' # some people prefer grep -E 'foo|bar'
egrep is the oldest and most portable form of the grep command using Extended Regular Expressions (EREs). -E is a POSIX-required switch.