Command menu (terminal,bash,fzf).

Oct 09, 2022, 17:09:47



.bashrc :

#   folder,export PATH : Private path where the "type -p" command will find your own files.
#   source : Short .bashrc entry to make the original .bashrc more transparent. Custom settings and files in a separate directory. Easily portable, i.e. modular architecture.
#   $folder content :
#   $ ls $folder
#   backup.txt  bash_settings  cmd.txt  hdd.txt  install.txt  pacman.txt  swap.txt

folder=~/Downloads/bash && export PATH="$folder:$PATH" && source bash_settings



~/Downloads/bash/bash_settings (or "$folder"/bash_settings) :

#   Command menu with multiple pages (bash, fzf).
#
#   fake readline (up and delete line) source :
#   https://stackoverflow.com/questions/18362837/how-to-display-and-refresh-multiple-lines-in-bash
#   https://stackoverflow.com/questions/22322879/how-to-print-current-bash-prompt
#
#   fzf insert = edit source :
#   https://github.com/junegunn/fzf/wiki/examples#opening-files
#
#   neccesary packages :
#   coreutils : head, tail
#   ncurses : tput
#
#   vaiables :
#   pn : page number
#   pmax : page maximum
#   pages,line,cmd,key
#
#   The while, do, continue, done are only used to replace goto. Instead of goto, continue jumps to the beginning.



pn=0                                    # neccesary

function menu {

if [ $# -eq 0 ]                         # No page, then exit.
then
return
fi

pages=($@)                              # Loading pages (.txt) into a variable (array).

let pmax=${#pages[@]}-1                 # Number of text files (or pages).

if [ $pn -gt $pmax ]
then
pn=$pmax
fi

while :
do


line=$(< $(type -p ${pages[pn]}) fzf --reverse --exact --no-color --no-info --expect=insert,right,left --no-clear)


if [ "$line" = "" ]                     # fzf escape, ctrl-c, empty string
then
tput rmcup && tput cuu1 && tput el      # restore screen (fzf --no-clear) and fake readline (up and delete line)

cmd=""
break                                   # goto the end (done)

fi

key=$(head -1 <<< "$line")              # https://github.com/junegunn/fzf/wiki/examples#opening-files (example of using --expect)

if [ "$key" = right ]                   # paging right
then
let pn=pn+1

    if [ $pn -gt $pmax ]
    then
    pn=0
    fi

continue                                # goto the top (do)

fi

if [ "$key" = left ]                    # paging left
then
let pn=pn-1

    if [ $pn -lt 0 ]
    then
    pn=$pmax
    fi

continue                                # goto the top (do)

fi

cmd=$(head -2 <<< "$line" | tail -1)    # https://github.com/junegunn/fzf/wiki/examples#opening-files (example of using --expect)

if [ "$key" = insert ]                  # only insertion
then
tput rmcup && tput cuu1 && tput el      # restore screen (fzf --no-clear) and fake readline (up and delete line)
read -p "${PS1@P}" -eri "$cmd" cmd

fi

history -s $FUNCNAME $@
history -s $cmd

tput rmcup && tput cuu1 && tput el      # restore screen (fzf --no-clear) and fake readline (up and delete line)
echo "${PS1@P}"$cmd

break                                   # goto the end (done)

done

eval $cmd

}



#   Personal examples.

alias m='menu cmd.txt pacman.txt backup.txt hdd.txt swap.txt install.txt'

#   Older one page settings (out of habit).

alias b='menu backup.txt' s='menu cmd.txt' pk='menu pacman.txt' hdd='menu hdd.txt' swap='menu swap.txt' i='menu install.txt'