Returns a substring of a string
(substr string start [length])
substr function starts at the start character position of string and continues for length characters.The
A positive integer indicating the starting position in string. The first character in the string is position 1.
A positive integer specifying the number of characters to search through in string. If length is not specified, the substring continues to the end of string.
Command: (substr "abcde" 2)
Command: (substr "abcde" 2 1)
Command: (substr "abcde" 3 2)