oneliner - insert line in file after regexpres

[simpson]

I am looking to insert a line of text in a file after a specific line. I know how to do it based on the line number:
#perl -pi -le 'print "New line Insertion" if $. == 100' file.txt

How would i adjust the example above for inserting "New Line Insertion" on the line after my search pattern?

Any help with this would be greatly appreciated.
Mike

 

[Annihilannic]

Use -n instead of -p (i.e. disable AutoPrint^TM), and do the printing yourself.

#perl -ni -le 'print; print "New line Insertion" if /regex/' file.txt

Annihilannic.