regex101: Single line of .env file

Non-Capturing Group(?:^|^)

1st Alternative^

^start of line

2nd Alternative^

^start of line

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

Non-Capturing Group(?:export\s+)?

?repeats the group contents below at most once:

exportthe literal text export (case sensitive)

\s+any whitespace character, repeated at least once

Group 1([\w.-]+)

Character Class[\w.-]+

+matches at least one character from the set below:

\wany word character

.the literal . (46₁₀ / 56₈ / 2E₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Non-Capturing Group(?:\s*=\s*?|:\s+?)

1st Alternative\s*=\s*?

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

=the literal = (61₁₀ / 75₈ / 3D₁₆)

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

2nd Alternative:\s+?

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\s+?any whitespace character, repeated at least once

Group 2(\s*'(?:\\'|[^'])*'|\s*\"(?:\\\"|[^\"])*\"|\s*`(?:\\`|[^`])*`|[^#\r\n]+)?

?repeats the group contents below at most once:

1st Alternative\s*'(?:\\'|[^'])*'

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

'the literal ' (39₁₀ / 47₈ / 27₁₆)

Non-Capturing Group(?:\\'|[^'])*

*repeats the group contents below any number of times:

1st Alternative\\'

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

'the literal ' (39₁₀ / 47₈ / 27₁₆)

2nd Alternative[^']

Negated Character Class[^']

'the literal ' (39₁₀ / 47₈ / 27₁₆)

2nd Alternative\s*\"(?:\\\"|[^\"])*\"

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

\"the literal " (34₁₀ / 42₈ / 22₁₆)

Non-Capturing Group(?:\\\"|[^\"])*

*repeats the group contents below any number of times:

1st Alternative\\\"

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

\"the literal " (34₁₀ / 42₈ / 22₁₆)

2nd Alternative[^\"]

Negated Character Class[^\"]

\"the literal " (34₁₀ / 42₈ / 22₁₆)

3rd Alternative\s*`(?:\\`|[^`])*`

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

`the literal ` (96₁₀ / 140₈ / 60₁₆)

Non-Capturing Group(?:\\`|[^`])*

*repeats the group contents below any number of times:

1st Alternative\\`

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

`the literal ` (96₁₀ / 140₈ / 60₁₆)

2nd Alternative[^`]

Negated Character Class[^`]

`the literal ` (96₁₀ / 140₈ / 60₁₆)

4th Alternative[^#\r\n]+

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

Non-Capturing Group(?:#.*)?

Non-Capturing Group(?:$|$)

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

(?:^|^)\s*(?:export\s+)?([\w.-]+)(?:\s*=\s*?|:\s+?)(\s*'(?:\\'|[^'])*'|\s*\"(?:\\\"|[^\"])*\"|\s*`(?:\\`|[^`])*`|[^#\r\n]+)?\s*(?:#.*)?(?:$|$)

Test String
New

FOO=BAR
  FOOISH = BARISH  
export ZEBRA=ELEPHANT
FOO=bar none
JUNK=an experiment #ends here

Regular Expression

Test StringNew

Test String
New