getopt ('switches'[, \%opts])
switches is a string of the command-line
options that take arguments. For each option,
getopt sets
$opt_x (in which
x is the switch) to the value entered as
an argument. If \%optsis specified, it is a reference to a hash in which
getopt sets the key to the name of the switch and
the value to the argument (and the $opt_ variables
are not set).
getopts ('switches'[, \%opts])
Like getopt, except that all valid options are
included in switches, and options that
take an argument are followed by a colon (:). For example:
getopt('oDI') # -o, -D, & -I take arguments; there may
# be other options
getopts('o:DI') # -o, -D, and -I are the only valid
# options; only -o takes an argument
\%opts means the same
as with getopt.