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Note to self: How to use screen

notetoselfThis posting will start a series of rather short articles, where I present things that I use from time to time but tend to forget how to do it :)
The first serving will deal with the undeniable useful Unix command screen. Screen can open a virtual screen, there you can start running long term processes and you can detach at any time and reattach later, while the process continues to run. You can view screen as a nohup on steroids. Start it with a blank shell and create a session with the symbolic name testo:

screen -S testo

You are greeted with … well, a fresh and clean shell. Here you can start doing things that will run a long time. To detach from that screen, use the key sequence ctrl-a d. Nearly all key sequences for screen start with crtl-a. And the “d” stands for “detach”. To see whats going on behind your back, use the screen list command:

screen -ls
There is a screen on:
        1387.testo      (31.07.2015 17:34:57)   (Detached)
1 Socket in /var/run/screen/S-vmg.

Here 1387.testo is the key to the session, consisting of the process id and the symbolic name:

ps auxf
 1387 ?        Ss     0:00 SCREEN -S testo
 1388 pts/2    Ss+    0:00  \_ /bin/bash

To reattach to the screen, you might have guessed it, you can use a screen reattach:

screen -r testo

You can detach and reattach to the screen as often as you like. When done with your long running processes, just log out of the screen using ctrl-d. You will be informed that the screen has been shut down:

[screen is terminating]

Adding a proxy to the Atom editor config on Windows

Atom-Logo Reading the user forum discussions about proxy configuration for atom can be a bit misleading for users on Windows. Suppose you’re running a recent Windows version. Suppose you’ve installed atom. Suppose you found out that the binary lives in


(version number can be different …)
and suppose you are situated behind a corporate firewall/proxy which prevents you from installing packages and updates.
Looking around you can find postings specifying what to write into your .apmrc config file (which is the config of apm, the atom package manager). Now you look for that file and find it in


Every time you try to write some config to that file, it will be deleted, as it is autogenerated (just as the comment in the file says …).
The file, you are looking for probably is not existant yet. Just create one named


and put in the following content:

https-proxy = http://:
http-proxy = http://:
strict-ssl = false

Replace and with your values. Save the file, restrt atom and you’re done. Seems hard to distibuish .atom.apmrc and .atom.apm.apmrc some times …

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Playing around with services in grails console

Suppose you have a grails project and have witten a service doing some database magic to pull together data. Now suppose the very unlikely case that it’s not running that smooth than you thought. To expel the black magic you probably would like to use the grails console to play around with your domain classes and services. Using a service is as simple as importing the domain class and using it:

import myproject.Domainclass
def instance=Domainclass.get(3)

The service classes however are not that accessible to manipulation. You need to request the service bean instance by name from the application context named ctx:

def mcs=ctx.getBean("myCoolService")
def allThings=mcs.getAllThings()

Remember to use the (lowercase) instance name when calling getBean() just as it would be injected into your controller:

class GraphController {
    MyCoolService myCoolService

Pulling the strings together you can do more complex tests:

import myproject.Domainclass

def mcs=ctx.getBean("myCoolService")
def instance=Domainclass.get(3)
println "-----------------------------------------"
def allThings=mcs.getAllThings()
allThings.each { n -> println"\t"+n.thingstype+"\t\t" }

Hope that helps. As always: in case of questions or corrections / additions please leave a comment :)


Adding assets in Grails 3

When using modern web development technologies, you often come across frameworks or libraries which use additional resources apart from css stylesheets, images and javascript. One such example is Font Awesome, which needs sone font files, located in the /fonts subdirectory of the unzipped package. In Grails 2 lazy coders would put this directory in the /wep-app folder. In Grails 3 you should (!) use the asset pipeline for these files to and here are two ways that work:

  1. Simply put the files into the grails-app/assets/stylesheets folder. This is not a very elegant way nor is it the intended way to use the asset pipeline.
  2. Put the fonts directory parallel to stylesheets, images and javascript into the grails-app/assets/ folder. For the asset pipeline to know the new directory, specify it in the build.gradle file:
    assets {
        minifyJs = true
        minifyCss = true
        includes = ["fonts/*"]

    Last thing to do is to patche the font file paths in the font-awesome.css and/or font-awesome.min.css file. Just remove the “../fonts/” part of the url() path, so they all look like this:

    font-family: 'FontAwesome';
    src: url('fontawesome-webfont.eot?v=4.3.0');

    Thats all.

This post by David Estes put me on the right track, since the official documentation doesn’t mention Grails 3 issues. Thanks David!