(PHP 4, PHP 5, PHP 7) Format a number with grouped thousands

(PHP 4, PHP 5) Make regular expression for case insensitive match

(PHP 4, PHP 5, PHP 7) Return part of a string

(PHP 4, PHP 5) Case insensitive regular expression match

(PHP 4, PHP 5, PHP 7) Make a string lowercase

(PHP 4 >= 4.0.5, PHP 5, PHP 7) Get numeric formatting information

(PHP 4 >= 4.3.0, PHP 5, PHP 7) Calculate the sha1 hash of a string

(PHP 4 >= 4.3.0, PHP 5, PHP 7) Formats a number as a currency string

(PHP 4, PHP 5, PHP 7) Find the first occurrence of a string

(PECL ssdeep >= 1.0.0) Create a fuzzy hash from a string