perlcompatible regex

This blog highlights how to detect hidden Unicode characters, such as zero-width spaces, in Linux using `grep -P`. Invisible characters can disrupt data processing, often entering text through copying and paste actions. The `grep -P` command supports Perl-compatible regular expressions, which can identify these invisible characters effectively. The article provides examples and scripts to aid users in checking multiple files for these hidden entities, ensuring data integrity and precision in text handling.