Regular Expressions 101

Explanation

Pro

Accel=the literal text Accel= (case sensitive)

\s*any whitespace character, repeated any number of times

Group 1([+-]?(?:\d*\.?\d+|\d+\.\d*))

Character Class[+-]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Non-Capturing Group(?:\d*\.?\d+|\d+\.\d*)

1st Alternative\d*\.?\d+

\d*a digit, repeated any number of times

\.?optionally matches the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

2nd Alternative\d+\.\d*

\d+a digit, repeated at least once

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d*a digit, repeated any number of times

\s*any whitespace character, repeated any number of times

Group 2((?!\d)[A-Za-z\d+^/*()-]+)

Negative Lookahead(?!\d)

\da digit

Character Class[A-Za-z\d+^/*()-]+

+matches at least one character from the set below:

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

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

\da digit

+the literal + (43₁₀ / 53₈ / 2B₁₆)

^the literal ^ (94₁₀ / 136₈ / 5E₁₆)

/the literal / (47₁₀ / 57₈ / 2F₁₆)

*the literal * (42₁₀ / 52₈ / 2A₁₆)

(the literal ( (40₁₀ / 50₈ / 28₁₆)

)the literal ) (41₁₀ / 51₈ / 29₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Positive Lookahead(?=\s*[_.\s])

\s*any whitespace character, repeated any number of times

Character Class[_.\s]

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\sany 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

26 tokens

Regular Expression

Accel=\s*([+-]?(?:\d*\.?\d+|\d+\.\d*))\s*((?!\d)[A-Za-z\d+^/*()-]+)(?=\s*[_.\s])

New

FilePrefix_Speed= 3.5 kmph_Accel= +0.5 m/(s^2) _Height=+7ms_Set=High.txt
FilePrefix_Speed= 3.5 kmph_Accel= +0. m/(s^2) _Height=+7ms_Set=High.txt

Substitution

FilePrefix_Speed= 3.5 kmph_Accel= +0.5 m/(s^2) _Height=+7ms_Set=High.txt
FilePrefix_Speed= 3.5 kmph_Accel= +0. m/(s^2) _Height=+7ms_Set=High.txt