egrep linux command

egrep

egrep [options] [regexp] [files]

Search one or more files for lines that match an extended regular expression regexp. egrep doesn't support the regular expressions (, ), n, <, >, but does support the other expressions, as well as the extended set +, ?, |, and ( ). Remember to enclose these characters in quotes. Regular expressions are described in Chapter 9, 'Pattern Matching'. Exit status is 0 if any lines match, 1 if none match, and 2 for errors.

See grep for the list of available options. Also see fgrep. egrep typically runs faster than those commands.

Examples

Search for occurrences of Victor or Victoria in file:

Find and print strings such as old.doc1 or new.doc2 in files, and include their line numbers: