Описание

Procedural style

Return part of a string start'th position in string, counting from zero. If start is negative, the returned string will start at the start'th character from the end of string. at most length characters beginning from start (depending on the length of string). If string is less than or equal to start characters long, FALSE will be returned. If length is given and is negative, then that many characters will be omitted from the end of string (after the start position has been calculated when a start is negative). If start denotes a position beyond this truncation, an empty string will be returned.