command_not_found_handle.bash

# I've always disliked the "./configure" incantation - it's right here! I
# shouldn't need to tell the shell where to look for it. But of course,
# putting '.' in your $PATH is terrible -- it's insecure and throws permission
# errors if you try to 'execute' regular files. Bash 4's `shopt -s autocd`
# solves half the problem; and the ability to override
# command_not_found_handle() solves the other.
#
# This is an OS X-oriented script that attempts to do the most intelligent
# thing possible when you enter the name of a file in your $PWD into the bash
# prompt. It will:
#
# 1. Prompt to execute the file, if its executable bit is set
# 2. Preview media files in Quick Look
# 3. Prompt to open a file in its associated app, if one exists
# 4. Open text, XML, and files with no associated app in $EDITOR
#
# Known bugs/tricky behaviors:
# * bash chokes on file names containing parentheses.
# * Executables with spaces in their names are not supported.
# * If autocd is on, entering a .app bundle's name with navigate into it,
#   rather than execute it.
# * If there is a command in $PATH with the same name as a file in $PWD, the
#   command will be executed.
#
# Room for improvement:
# * Support for xdg-open, gnome-open and GNOME Sushi

command_not_found_handle() {
    # do not run when inside Midnight Commander or within a Pipe
    if test -n "$MC_SID" -o ! -t 1 ; then
        echo $"$1: command not found"
        return 127
    fi

    if test -x "$1"; then # ∃ an executable matching the first arg?
        # confirmation prompt
        read -p "execute $PWD/$*? " -n 1 -r
        if [[ $REPLY =~ ^[Yy]$ ]]; then
            printf "\n"
            ./$* # execute with args
        else
            printf "\n"
        fi
    elif test -f "$*"; then # a file?
        local FILE="$*"
        local MIME_TYPE=$(file --mime-type --brief "$FILE")
        local MIME_CHARS=[[:alnum:]'!#$&.+-^_']
        # open text files in $EDITOR
        if [[ $MIME_TYPE =~ (text/$MIME_CHARS+|application/($MIME_CHARS+\+)?xml|application/x-empty) ]]; then
            $EDITOR "$FILE"
        # view media files in quicklook
        elif [[ $MIME_TYPE =~ (image|audio|video)/$MIME_CHARS+ ]]; then
            qlmanage -p "$FILE" &> /dev/null
        else
            local DEFAULT_APP=$(osascript -e "on run argv" -e "return POSIX path of default application of (info for item 1 of argv)" -e "end run" "$FILE" 2> /dev/null)
            if [[ -n $DEFAULT_APP ]]; then
                printf "open $PWD/$FILE"
                #    'open '       '/'          ' with '             ' ? █'
                if (( 5 + ${#PWD} + 1 + ${#FILE} + 6 + ${#DEFAULT_APP} + 4 <= $COLUMNS )); then
                    printf " "
                else
                    printf "\n"
                fi
                read -p "with $DEFAULT_APP ? " -n 1 -r
                if [[ $REPLY =~ ^[Yy]$ ]]; then
                    open -a "$DEFAULT_APP" "$FILE"
                fi
                printf "\n"
            else
                $EDITOR "$FILE"
            fi
    fi
    else
        echo $"$1: command not found"
        return 127
    fi
}