Openfire does not listen to port 5222
Problem : Openfire server does not listen to port 5222. Symptoms : netstat -tulpn | grep LISTEN – will not show ports 5222 or 5223. tail -1000 /opt/openfi...
Category: Notes
Precedence and best practices for Apache ProxyPass
To set priority/order of ProxyPass (and ReverseProxyPass) rules, write the one with most precedence above the rest, and so forth. Delete any non-dot-con...
Open port 80 for Apache2 on Ubuntu using the Ubuntu firewall service
For cases where Apache2 is available within the box/local host, but not from LAN, you might have to open port 80 in the firewall. This is a simple comman...
Extract a selected polygon from an image to a new image file in Java
A reference code to extract a selected shape (this case polygon, could be another shape like Rectangle) – [java] BufferedImage in = ImageIO.read(new File(...
Torch installation fails with message “Error. OpenBLAS could not be compiled”
Problem : Torch installation fails to install dependencies (“bash install-deps”) with the message “Error. OpenBLAS could not be compiled”...
Fix : No sound on Ubuntu (16.04) after a Bluetooth audio device power off.
Problem : After Bluetooth speakers were abruptly switched off, Ubuntu 16.04 on Alienware (17 R2) stopped producing sounds on its analog sound card. Reason : Dou...
Installing NetBeans IDE in Linux
Go to the link – https://netbeans.org/downloads/ Select Platform as Linux(x86/x64). Download the installer for NetBeans. From the terminal, navigat...
Installing Oracle Database XE in Linux
To install Oracle Database XE: 1. Log on to your computer with root permissions. 2. Go to the following Web site: http://www.oracle.com/technetwork/database/exp...
Downloading Youtube Videos
Go to the link of the video which you want to download. Replace the URL by adding ‘ss’ before ‘youtube’ and press Enter. You are directe...
Using Database Link in Oracle
Suppose data from a table X in database D is to be copied into table Y in the same database, then the problem can be solved easily by executing the query –...