Regular Expressions 101

1st Alternative(?<=^FS-[a-zA-Z0-9]*)[a-z]

Positive Lookbehind(?<=^FS-[a-zA-Z0-9]*)

^start of line

FS-the literal text FS- (case sensitive)

Character Class[a-zA-Z0-9]*

*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)

Character Class[a-z]

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

2nd Alternative[\p{Zs}\ta-z](?=[a-zA-Z0-9\p{Zs}\t]*$)

Character Class[\p{Zs}\ta-z]

\p{Zs}a space separator with non-zero width

\ta tab character (ASCII 9)

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

Positive Lookahead(?=[a-zA-Z0-9\p{Zs}\t]*$)

Character Class[a-zA-Z0-9\p{Zs}\t]*

*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)

\p{Zs}a space separator with non-zero width

\ta tab character (ASCII 9)

$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

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

(?<=^FS-[a-zA-Z0-9]*)[a-z]|[\p{Zs}\ta-z](?=[a-zA-Z0-9\p{Zs}\t]*$)

New

(S)FSK-69/23/GFK/ 1 2 
(S)FSK-69/23/GFK/12

FS-4444g/23g/F/1g1
FS-4444/23g/F/11