use Filter::sh 'command' ;
As with all source filters its scope is limited to the current source file only. Every file you want to be processed by the filter must have a
use Filter::sh 'command' ;
near the top.
Here is an example script which uses the filter:
use Filter::sh 'tr XYZ PQR' ;
$a = 1 ;
print "XYZ a = $a\n" ;
And here is what it will output:
PQR = 1
Be especially careful when stacking multiple instances of the filter in a single source file.