Regular Expressions (regex)

Regular Expressions (regex) are a sequence of characters that define a search pattern.

Grep is a command-line utility for searching plain-text data sets for lines that match a regular expression. Its name comes from the ed command g/re/p (globally search a regular expression and print), which has the same effect: doing a global search with the regular expression and printing all matching lines.

• `` - escape character (e.g. . - match a dot character)

• $ - end of line (e.g. a$ - lines that end with a)

• ^ - start of line (e.g. ^a - lines that start with a)

• . - any character (e.g. a.b - lines that contain a, then any character, then b)