Regular Expressions 101

Explanation

Pro

1st Alternative(?<!\d|^)(?<!(?<![^\W_])(?:sha|md))(?=\d)

Negative Lookbehind(?<!\d|^)

1st Alternative\d

\da digit

2nd Alternative^

^start of line

Negative Lookbehind(?<!(?<![^\W_])(?:sha|md))

Negative Lookbehind(?<![^\W_])

Negated Character Class[^\W_]

\Wany non-word character

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Non-Capturing Group(?:sha|md)

1st Alternativesha

shathe literal text sha (case sensitive)

2nd Alternativemd

mdthe literal text md (case sensitive)

Positive Lookahead(?=\d)

\da digit

2nd Alternative(?<=\d)(?!\d|$)

Positive Lookbehind(?<=\d)

\da digit

Negative Lookahead(?!\d|$)

1st Alternative\d

\da digit

2nd Alternative$

$end of line

3rd Alternative_

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

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

Detailed match information will be displayed here automatically.

26 tokens

(?<!\d|^)(?<!(?<![^\W_])(?:sha|md))(?=\d)|(?<=\d)(?!\d|$)|_

New

Aisha256
ai_sha256
test123
84test
test md5
sha256
word two sha1
w0rd
test_md5
sha256
md5

Aisha256
ai_sha256
test123
84test
test md5
sha256
word two sha1
w0rd
test_md5
sha256
md5