Example of a regular expression (I)

Syntax	Function
^	Beginning of Line
$	End of line
^ [The]	Line starting with
[Ss] ignal [ll]	Match the word signal, signal
[Ss] ignal [ll] \.	Same as above, but add a sentence
[MayMay]	Rows that contain uppercase or lowercase letters of May
^ User $	Rows that only contain users
[Tty] $	Line ending with tty
\.	Rows with periods
^ D.. X.. X.. x	Directories With executable permissions for users, user groups, and other user group members
^ [^ L]	Exclude the list of associated Directories
[. * 0]	Add any character before or after 0
[000 *]	000 or more
[II]	Upper or lower case I
[II] [NN]	Uppercase or lowercase I or N
[^ $]	Empty row
^ ...... $	Contains 6 Characters

Example of a regular expression (I)