#!/usr/bin/env sh
# YES_ZSH
# YES_BASH
# YES_DASH
# YES_ASH
# YES_BB_AWK
# YES_OT_AWK

dfu() { ### @-
    ### pretty-print `df` in GiB.
    ###
    ### ```
    ### $ dfu
    ### Filesystem              Used     Max    Left    Misc
    ### /dev                    0.00    0.46    0.46    0.00
    ### /                      17.20   23.22    6.01    1.27
    ### ```

    [ $# -le 0 ] || { printf "%s\n" "$0: too many arguments" >&2; return 1; }
    df -xtmpfs | awk '
    NR==1{printf"%-20s %7s %7s %7s %7s\n","Filesystem","Used","Max","Left","Misc"}
    NR>1{printf"%-20s %7.2f %7.2f %7.2f %7.2f\n",$6,$3/2^20,($3+$4)/2^20,($4)/2^20,($2-$4-$3)/2^20}'
}

[ -n "${preload+-}" ] || dfu "$@"