Regular Expressions 101

^start of line

Non-Capturing Group(?:[\dA-Z-]+\.(?:jpe?g|png|gif))?

?repeats the group contents below at most once:

Character Class[\dA-Z-]+

+matches at least one character from the set below:

\da digit

A-Zone character from A (65₁₀) to Z (90₁₀) (case insensitive)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Non-Capturing Group(?:jpe?g|png|gif)

1st Alternativejpe?g

jpthe literal text jp (case insensitive)

e?optionally matches the literal e (101₁₀ / 145₈ / 65₁₆) (case insensitive)

gthe literal g (103₁₀ / 147₈ / 67₁₆) (case insensitive)

2nd Alternativepng

pngthe literal text png (case insensitive)

3rd Alternativegif

gifthe literal text gif (case insensitive)

Non-Capturing Group(?:, (?:[\dA-Z-]+\.(?:jpe?g|png|gif)))*

*repeats the group contents below any number of times:

, the literal text ,

Non-Capturing Group(?:[\dA-Z-]+\.(?:jpe?g|png|gif))

Character Class[\dA-Z-]+

+matches at least one character from the set below:

\da digit

A-Zone character from A (65₁₀) to Z (90₁₀) (case insensitive)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Non-Capturing Group(?:jpe?g|png|gif)

1st Alternativejpe?g

jpthe literal text jp (case insensitive)

e?optionally matches the literal e (101₁₀ / 145₈ / 65₁₆) (case insensitive)

gthe literal g (103₁₀ / 147₈ / 67₁₆) (case insensitive)

2nd Alternativepng

pngthe literal text png (case insensitive)

3rd Alternativegif

gifthe literal text gif (case insensitive)

$end of line

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

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?:[\dA-Z-]+\.(?:jpe?g|png|gif))?(?:, (?:[\dA-Z-]+\.(?:jpe?g|png|gif)))*$

Test String
New

bad_image.jpg

2017-06-01-03-55-00-5930782c5c0b1.jpg
2017-06-01-03-55-00-5930782c5c0b1.jpeg, bad_image.jpg
2017-06-01-03-55-00-5930782c5c0b1.png, 2017-06-01-03-55-00-5930782c5c0b1.gif

Regular Expression

Test StringNew

ExtractionProcessing...

Test String
New

Extraction
Processing...