Regex expression matching block of lines

Question

I have this kind of file:

Analysis of its root cause:
Blablablablabla
blabablabkjhjk
kjbsqbdqbds

Details of the fix
blablabla

Analysis of its root cause:
fddsfsdfsdfdsfs
blnskdbbqbbb
xxxxggggggg

Details of the fix
blablabla

Analysis of its root cause is repeated x times in the file. I would like to get the block of text delimited by "Analysis of its root cause" and "Details of the fix".

Thanks a lot for your help.

I tried to edit my post to say Hello but it does not work, so Hello :) — Kmel
– Kmel, Commented Nov 28, 2017 at 17:04

Anderson Pimentel · Accepted Answer · 2017-11-28 17:50:47Z

2

I'm pretty sure there is some better way to do this, but that's what I could manage:

/(?(?<=Analysis of its root cause:\n)((.*\n)*)(?=Details of the fix\n))/gU

I'm using positive lookahead and lookbehind, and the following modifiers:

g - global - Don't return after first match

u - Ungreedy - Make quantifiers lazy

Try it online: https://regex101.com/r/xpz7pg/2

answered Nov 28, 2017 at 17:50

Anderson Pimentel

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user1717259 · Accepted Answer · 2017-11-28 17:53:58Z

1

Not a regex answer, but using perl

Put your lines into a single file.

 perl -e '$/="Analysis of its root cause:"; #Sets the record delimiter 

      while(<>){ #Iterates over the file, record by record

      chomp; #Removes the delimiter

      if ($_ =~ /\n(.*?)\nDetails of the fix\n(.*)\n/s){ #Matches strings between Details of the fix. . is allowed to match newline

      print "ONE:$1TWO:$2"} # $1 is the analysis, $2 is the details
      }'
      file.txt

Output

ONE:Blablablablabla
blabablabkjhjk
kjbsqbdqbds
TWO:blablabla
ONE:fddsfsdfsdfdsfs
blnskdbbqbbb
xxxxggggggg
TWO:blablabla

edited Nov 28, 2017 at 17:53

answered Nov 28, 2017 at 17:10

user1717259

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