regex101: PCRE (Legacy) Match Workspace

^start of line

\na line-feed (newline) character (ASCII 10)

Group 1([a-zA-Z0-9+\/=\n]*)

Character Class[a-zA-Z0-9+\/=\n]*

*matches any number of characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

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

0-9one character from 0 (48₁₀) to 9 (57₁₀)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

=the literal = (61₁₀ / 75₈ / 3D₁₆)

\na line-feed (newline) character (ASCII 10)

$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

Search reference

Regular Expression

^\n([a-zA-Z0-9+\/=\n]*)\n$

New

Subject: Fwd: Test.
Thread-Topic: Test.
Date: Tue, 5 May 2020 19:02:42 +0000

U3ViamVjdCB0byBiYXNlNjQgZGVjb2Rl

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Content-Transfer-Encoding: base64

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--_000_DB6PR10MB1831AAD962E88A95B21547589EA70DB6PR10MB1831EURP_--

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Regular Expressions 101

Regular Expression

Extraction