shiftShift positional parameters to the left by n.
SYNTAX shift [n] OPTIONS n : The number of parameters to shift (default = 1)
The positional parameters from
n+1 ... $#
are renamed to
$1 ... $#-n+1
Parameters represented by the numbers $# to n+1 are unset.
n must be a positive number less than or equal to $#.
The return status is zero unless n is greater than $# or less than zero.
shift is a BOURNE shell command and a POSIX `special' builtin.
getopts - Parse positional parameters