getopt_long_only
is like
getopt_long
, but "-" as well as
"--" can indicate a long option. If an option that
starts with "-" (not "--") doesn't
match a long option, but does match a short option, it is parsed as
a short option instead.
getopt_long_only
returns the option character if the
option was found successfully, or ":" if
there was a missing parameter for one of the options, or
"?" for an unknown option character, or
-1 for the end of the option list.
getopt_long_only
also returns the option character
when a short option is recognized. For a long option, they return val
if flag is NULL, and 0
otherwise. Error and -1 returns are the
same as for getopt
, plus
"?" for an ambiguous match or an
extraneous parameter.