[SOLVED] grep -P no longer works. How can I rewrite my searches?

Issue

It looks like the new version of OS X no longer supports grep -P and as such has made some of my scripts stop working, for example:

var1=`grep -o -P '(?<=<st:italic>).*(?=</italic>)' file.txt`

I need to capture grep's result to a variable and I need to use zero-width assertions, as well as \K:

var2=`grep -P -o '(property:)\K.*\d+(?=end)' file.txt`

Any alternatives would be greatly appreciated.

Solution

If you want to do the minimal amount of work, change

grep -P 'PATTERN' file.txt

to

perl -nle'print if m{PATTERN}' file.txt

and change

grep -o -P 'PATTERN' file.txt

to

perl -nle'print $& while m{PATTERN}g' file.txt

So you get:

var1=`perl -nle'print $& while m{(?<=<st:italic>).*(?=</italic>)}g' file.txt`
var2=`perl -nle'print $& while m{(property:)\K.*\d+(?=end)}g' file.txt`

---

In your specific case, you can achieve simpler code with extra work.

var1=`perl -nle'print for m{<st:italic>(.*)</italic>}g' file.txt`
var2=`perl -nle'print for /property:(.*\d+)end/g' file.txt`

Answered By - ikegami

Answer Checked By - Robin (WPSolving Admin)