shell - How do I grep for multiple patterns? - Unix & Linux Stack Exchange

shell - How do I grep for multiple patterns? - Unix & Linux Stack Exchange

The portable way is to use the newer syntax, extended regular expressions. You need to pass the -E option to grep to select it. On Linux, you can also type egrep instead of grep -E (on other unices, you can make that an alias).

grep -E 'foo|bar' *.txt

Another possibility when you're just looking for any of several patterns (as opposed to building a complex pattern using disjunction) is to pass multiple patterns to grep. You can do this by preceding each pattern with the -e option.

grep -e foo -e bar *.txt

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