[SOLVED] Look for pattern `{{ <anything inside> }}` in twig files (and deeper dirs) and output to a text file in a list

Issue

I'm searching a directory (and deeper directories) for twig files that have variables {{ something var name }} and I would like to output into a file (twig-vars.txt).

Maybe using grep and regex? This is not my wheelhouse, so thanks in advance!

Example output (twig-vars.txt):

{{ somevar }}
{{ someothervar }}
{{ site.url }}
{{ ... }}

Solution

With grep in PCRE mode:

grep -oP '{{\s*\K[\w.]+' file
-------8<------------------
somevar
someothervar
site

Or with Perl:

perl -nE 'say $& if/{{\s*\K[\w.]+/' file
-------8<------------------
somevar
someothervar
site

The regular expression matches as follows:

Node	Explanation
{{	'{{'
\s*	whitespace (\n, \r, \t, \f, and " ") (0 or more times (matching the most amount possible))
\K	resets the start of the match (what is Kept) as a shorter alternative to using a look-behind assertion: look arounds and Support of K in regex
[\w.]+	any character of: word characters (a-z, A- Z, 0-9, _), '.' (1 or more times (matching the most amount possible))

Or with awk

awk -F'{{ | }}' '{print $2}' file
-------8<------------------
somevar
someothervar
site.url

Answered By - Gilles Quénot

Answer Checked By - Clifford M. (WPSolving Volunteer)