Question

I need to match the abcd in text which may contain:

abcdssss

ffffabcdksdks

AbCdfdjb

aBCd

In a nutshell any match is qualified which can match caps or no caps with the text with other text or as a seperate word

EDIT

Environment : PHP

Answer 1

This is your solution for PHP:

if (preg_match('/abcd/i', $subject)) {
    # Successful match
} else {
    # Match attempt failed
}

It finds abcd anywhere, including as part of a word, as you asked for. It is also case-insensitive due to the i suffix.