Single and double dash options #79
Description
Is it correct that one is called unix-style while the other gnu-style ?
UNIX-style usage
tar -A [OPTIONS] ARCHIVE ARCHIVE
tar -c [-f ARCHIVE] [OPTIONS] [FILE...]
tar -d [-f ARCHIVE] [OPTIONS] [FILE...]
tar -t [-f ARCHIVE] [OPTIONS] [MEMBER...]
tar -r [-f ARCHIVE] [OPTIONS] [FILE...]
tar -u [-f ARCHIVE] [OPTIONS] [FILE...]
tar -x [-f ARCHIVE] [OPTIONS] [MEMBER...]
GNU-style usage
tar {--catenate|--concatenate} [OPTIONS] ARCHIVE ARCHIVE
tar --create [--file ARCHIVE] [OPTIONS] [FILE...]
tar {--diff|--compare} [--file ARCHIVE] [OPTIONS] [FILE...]
tar --delete [--file ARCHIVE] [OPTIONS] [MEMBER...]
tar --append [-f ARCHIVE] [OPTIONS] [FILE...]
tar --list [-f ARCHIVE] [OPTIONS] [MEMBER...]
tar --test-label [--file ARCHIVE] [OPTIONS] [LABEL...]
tar --update [--file ARCHIVE] [OPTIONS] [FILE...]
tar --update [-f ARCHIVE] [OPTIONS] [FILE...]
tar {--extract|--get} [-f ARCHIVE] [OPTIONS] [MEMBER...]