[caption id="attachment_5404" align="aligncenter" width="633"](https://codeyarns.files.wordpress.com/2015/01/20150105-eclipse-guideline.png) Set print margin in Eclipse[/caption]
A vertical guide line can help the programmer be aware of and comply with the line width of code. The guideline is called print margin in Eclipse.
It can be found in Windows -> Preferences -> General -> Editors -> Text editors section. You can also set the line width you want for the guideline.
Tried with: Eclipse Luna 4.4.1 and Ubuntu 14.04