mjhjmtu

Say I have this basic bash script for installing Vim plugins:

#!/usr/bin/env bash

plugins=(
tpope/vim-endwise
tpope/vim-fugitive
tpope/vim-surround
tpope/vim-unimpaired
)

rm -rf $HOME/.vim/pack/bundle/*
mkdir $HOME/.vim/pack/bundle/start

installplugin() 
 plugin=”$(echo “$1" 

for repo in $plugins[@]; do
 installplugin “$repo” &
done

wait

It clones each repository in the array plugins to ~/.vim/pack/bundle/start, and does so asynchronously.

Ignoring the async element of the script (the & at the end of installplugin “$repo” &) for the moment, how would I add a . to the end of a line such as Installing $plugin (which would show at the start of the installation process of a given plugin) every second or so, as a form of progress bar, perhaps outputting Done. on the same line after completion of that plugin, then moving on to the next plugin?

Here is my stab at the issue:

#!/usr/bin/env bash

plugins=(
tpope/vim-endwise
tpope/vim-fugitive
tpope/vim-surround
tpope/vim-unimpaired
)

rm -rf $HOME/.vim/pack/bundle/*
mkdir $HOME/.vim/pack/bundle/start

progressbar() 
 until [ $installed -eq 1 ]; do
 sleep 0.1
 echo -n '.'
 done


installplugin() sed -e ‘s/.*[/]//’)”
 git clone –depth=1 -q https://github.com/$1.git 
 $HOME/.vim/pack/bundle/start/$plugin
 rm -rf $HOME/.vim/pack/bundle/start/$plugin/.git*
 installed=1
 echo ' Done.'


for repo in $plugins[@]; do
 installplugin “$repo”
done

wait

It does not work, but I do not understand why.

What I assume is a simple thing to solve becomes much more complicated if you remember that the original script was asynchronous, as you would have to remember how many lines up the output of each Installing message is from the bottom, and then update the lines with dots until their respective plugin has been installed. I need to modify the original script to show the basic form of progress bar I described earlier?

It does not work since the shell variable installed is two different variables in the progressbar function (in its subshell environment) and in the installplugin function. The progressbar function is executed in a subshell since you start it as a background task. It will inherit the value from its parent environment when the function is started, but the parent will not be able to set a new value in the child environment (the progressbar subshell).

This still uses progressbar as a background task, but lets it set up a trap to exit the infinite loop. The main function, foo, triggers the trap by sending it the appropriate signal when it's done.

progressbar () 
 trap 'break' USR1

 while printf '.' >&2; do
 sleep 0.25
 done


foo () 
 progressbar & pid="$!"

 echo 'working...'
 sleep 5
 echo 'done.'

 kill -s USR1 "$pid"


foo