rc/sh/e

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

e() { ### @-
    ### wrap around `$EDITOR` to run it as root if necessary.
    ### this still needs some work to detect root-owned directories.
    ###
    ### ```
    ### $ e /etc/sudoers
    ### [sudo] password for notwa: 
    ### ```

    [ -z "$ZSH_OPTIONS" ] || setopt local_options sh_word_split
    local f= d= running= editor= needroot=0

    editor="${EDITOR%% *}"

    (running pid cmd | while read -r pid cmd; do
        if [ "$cmd" = "$editor" ]; then
            printf "%s (%s)\n" "$editor is already running" "$pid" >&2
            confirm
            exit
        fi
    done) || return

    for f in "$@"; do
        f="$(readlink -f "$f")" || continue

        [ -z "$MSYSTEM" ] || f="$(cygpath -u "$f")" || continue

        # easy: file exists, we have write permissions
        [ -w "$f" ] && continue

        # easy: file exists, but no write permissions
        [ -e "$f" ] && { needroot=1; break; }

        # hard: file may be in a directory that we can't inspect
        d="$f"
        while [ "${d%/*}" != "$d" ]; do
            d="${d%/*}"
            # NOTE: this gets weird with the root directory, not sure how to handle
            [ -e "$d" ] && [ ! -w "$d" ] && { needroot=1 && break; }
        done
        [ $needroot -eq 1 ] && break

        # easy: file just doesn't exist
    done

    if [ $needroot -eq 1 ] && [ -n "$MSYSTEM" ]; then
        # this pretty much never happens, because permissions are so busted, but...
        printf "NOTE: you need root permissions, but this is Windows." >&2
        printf "      this probably isn't going to work." >&2
        pause
        $EDITOR "$@"
    elif [ $needroot -eq 0 ]; then
        $EDITOR "$@"
    else
        sudo -e "$@"
    fi
}

[ -n "${preload+-}" ] || . ~/sh/preload || exit 2
eval ${preload:-preload} running confirm pause
[ -n "${preload+-}" ] || e "$@"