substr
substr - get or alter a portion of a stirng
substr EXPR,OFFSET,LEN
substr EXPR,OFFSET
Extracts a substring out of EXPR and returns it. First character is at
offset 0, or whatever you've set $[ to. If OFFSET is negative, starts
that far from the end of the string. If LEN is omitted, returns
everything to the end of the string. If LEN is negative, leaves that
many characters off the end of the string.
You can use the
substr()
function
as an lvalue, in which case EXPR must be an lvalue. If you assign
something shorter than LEN, the string will shrink, and if you assign
something longer than LEN, the string will grow to accommodate it. To
keep the string the same length you may need to pad or chop your value
using
sprintf()
.