interact.bash

interact.bash

# make commands interactive, essentially a bash version of http://thorstenball.com/fzz/.
# to use, copy to ~/.bash_profile or similar. requires ncurses.
# e.g. for an interactive `git grep`:
#     interact git grep {{}} | ...

interact() {
    # for printing ui create fd pointing to tty,
    # in case stdout is redirected
    exec 3> /dev/tty

    local cmd="$@"
    local input_locator="{{}}"
    local input=""
    local result=""

    # save current terminal output
    tput smcup >&3
    echo -n ">> $input" >&3
    while true; do
        read -rsn 1 char
        if [[ $char == $'\177' ]]; then
            # on backspace
            input="${input%?}"
        elif [[ $char == "" ]]; then
            # on return
            break
        elif [[ $char == $'\e' ]]; then
            # on escape
            return ""
        else
            input+="$char"
        fi
        # replace input locator with user input and evaluate command
        result=$(eval ${cmd/$input_locator/\"$input\"})

        # print input on first line of terminal followed by command output
        tput clear >&3
        echo -n ">> $input" >&3
        tput sc >&3
        tput cud1 >&3
        # trim command output to screen
        local lines=$(tput lines)
        local cols=$(tput cols)
        echo -n "$(head -n $((lines-1)) <<< "$result" | cut -c-$cols)" >&3
        tput rc >&3
    done
    # restore previous terminal output
    tput rmcup >&3
    echo "$result"
}