Regex capture group multiple times and other groups

Question

I'm trying to make a regex expression which capture multiple groups of data.

Here is some data example :

sampledata=X
B : xyz=1 FAB1_1=03 FAB2_1=01
A : xyz=1 FAB1_1=03 FAB2_1=01

I need to capture the X which should appear one time, and FAB1_1=03 , FAB2_1=01 , ... All the strings which starts with FAB .

So, I could capture all "FAB" like this :

/(FAB[0-9]_[0-9]=[0-9]*)/sg

But I could not include the capture of X using this expression :

/sampledata=(?<samplegroup>[0-9A-Z]).*(FAB[0-9]_[0-9]=[0-9]*)/sg

This regex only return one group with X and the last match of group of "FAB".

Answer 1

You can use

(?:sampledata=(\S+)|(?!^)\G)(?:(?!FAB[0-9]_[0-9]=).)*(FAB[0-9]_[0-9])=([0-9]*)‌​

See the regex demo

The regex is based on the \\G operator that matches either the start of string or the end of the previous successful match . We restrict it to match only in the latter case with a negative lookahead (?!^) .

So:

• (?:sampledata=(\\S+)|(?!^)\\G) - match a literal sampledata= and then match and capture into Group 1 one or more non-whitespace symbols -OR- match the end of the previous successful match
• (?:(?!FAB[0-9]_[0-9]=).)* - match any text that is not FABn_n= (this is a tempered greedy token )
• (FAB[0-9]_[0-9]) - Capture group 2, matching and capturing FAB followed with a digit, then a _ , and one more digit
• = - literal =
• ([0-9]*)‌​ - Capture group 3, matching and capturing zero or more digits

If you have 1 sampledata= block , you can safely unroll the tempered greedy token ( demo ) as

(?:sampledata=(\S+)|(?!^)\G)[^F]*(?:F(?!FAB[0-9]_[0-9]=)[^F]*)*?(FAB[0-9]_[0-9])=([0-9]*)
                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

That way, the expression will be more efficient.

If you have several sampledata blocks , enhance the tempered greedy token:

(?:sampledata=(\S+)|(?!^)\G)(?:(?!sampledata=|FAB[0-9]_[0-9]=).)*(FAB[0-9]_[0-9])=([0-9]*)

See another demo