local - create a temporary value for a global variable (dynamic scoping)
local EXPR
A local modifies the listed variables to be local to the enclosing block, subroutine, eval{}, or do. If more than one value is listed, the list must be placed in parentheses. See the section on Temporary Values via local() in the perlsub manpage for details, including issues with tied arrays and hashes.
But you really probably want to be using my() instead, because local() isn’t what most people think of as "local"). See the section on Private Variables via my() in the perlsub manpage for details.