What Does Egrep Return?

grep is used to search for text from a file or another command's output. It can return the lines where it finds a match or the lines where it doesn't.

What is an egrep?

egrep is an acronym for "Extended Global Regular Expressions Print". It is a program which scans a specified file line by line, returning lines that contain a pattern matching a given regular expression.

What does grep return if not found?

Indeed, grep returns 0 if it matches, and non-zero if it does not.