Regular Expressions 101

Explanation

Pro

Group 1(\!|(\!\!)|(\!>))

1st Alternative\!

\!the literal ! (33₁₀ / 41₈ / 21₁₆)

2nd Alternative(\!\!)

Group 2(\!\!)

\!the literal ! (33₁₀ / 41₈ / 21₁₆)

3rd Alternative(\!>)

Group 3(\!>)

\!the literal ! (33₁₀ / 41₈ / 21₁₆)

>the literal > (62₁₀ / 76₈ / 3E₁₆)

Group 4(|\s\s+)

1st Alternative — matches an empty string

2nd Alternative\s\s+

\sany whitespace character

\s+any whitespace character, repeated at least once

Group 5(\S)

\Sany non-whitespace character

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Match Information

Detailed match information will be displayed here automatically.

Quick Reference

25 tokens

Regular Expression

(\!|(\!\!)|(\!>))(|\s\s+)(\S)

New

Should not match:
! Hi
!! Hi
!> Hi

Needs to match, with ! !! !> being in a group:
!Hi
!!Hi
!>Hi
!  Hi
!!  Hi
!>  Hi
!   Hi
!!   Hi
!>   Hi

Ideally should not match:
!$OMP

Ideally should Match:
! $
!$ OMP
!$ Hi

Extraction

Should not match:
! Hi
!! Hi
!> Hi

Needs to match, with ! !! !> being in a group:
!Hi
!!Hi
!>Hi
!  Hi
!!  Hi
!>  Hi
!   Hi
!!   Hi
!>   Hi

Ideally should not match:
!$OMP

Ideally should Match:
! $
!$ OMP
!$ Hi