Regular Expressions 101

Positive Lookbehind(?<=^TASK )

^start of line

TASK the literal text TASK (case sensitive)

.*any Unicode character (except for line terminators), repeated any number of times

\r?optionally matches a carriage return (ASCII 13)

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

Positive Lookahead(?=(?:(?!TASK ).*\r?\n)*?fatal: \[hostname3]: FAILED! => {some info here}$)

Non-Capturing Group(?:(?!TASK ).*\r?\n)*?

*?repeats the group contents below any number of times:

Negative Lookahead(?!TASK )

TASK the literal text TASK (case sensitive)

.*any Unicode character (except for line terminators), repeated any number of times

\r?optionally matches a carriage return (ASCII 13)

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

fatal: the literal text fatal: (case sensitive)

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

hostname3]: FAILED! => {some info here}the literal text hostname3]: FAILED! => {some info here} (case sensitive)

$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

(?<=^TASK ).*\r?\n(?=(?:(?!TASK ).*\r?\n)*?fatal: \[hostname3]: FAILED! => {some info here}$)

New

TASK Wash the dishes
ok: [hostname1]
ok: [hostname2]
ok: [hostname3]
ok: [hostname4]
TASK Take out the trash
ok: [hostname1]
ok: [hostname2]
fatal: [hostname3]: FAILED! => {some info here}
ok: [hostname4]