Filter authentication fails from /var/log/roundcube/error

It checks the string to be only letters with no spaces or any other char than a-z and A-z

this is trim-like regex

Negative Lookahead Sample

Parse DocBlock tags to name & value

Searching for instances of strct_separate_cart with discount as a member

Checks if a string ends with digits

Aa

checks for valid limit clause of an sql statement