Linux / Unix Command To Optimize and Compress PNG Files In Bulk

Posted on in Categories , , , , , last updated October 22, 2016

I have lots of images in png format (over 250k+ png). Properly formatting and compressing png images can save many bytes of data. How do I compress and optimize png images on my amazon cloud account so that I can save bandwidth on cloudfront cdn account? How do I use an image compressor to create lossless compression on PNG files, with no effect on image quality in bulk using Red Hat Enterprise Linux bash shell?

Fix: VIM Fix UP and Down Keys Inserting A B C D Character On Remote SSH Session on a Linux or Unix Systems

Posted on in Categories , , last updated February 10, 2015

I am login to a remote server using a ssh client. I am annoyed with the arrow key behavior during insert mode in Vim. As soon as I hit arrow keys, vim display A B C D on screen. How do I fix this problem under Linux, FreeBSD, OpenBSD, NetBSD, Apple OS X or Unix-like operating systems? How can I fix arrow keys that display A B C D on remote shell?

RHN yum command: Unable to read consumer identity Warning and Solution

Posted on in Categories , last updated November 17, 2012

I am using yum update command with RHN to upgrade packages installed on my server, but getting the following warning on screen :

yum update -y
Loaded plugins: product-id, protectbase, rhnplugin, security, subscription manager:
Updating certificate-based repositories.
Unable to read consumer identity
0 packages excluded due to repository protections
Setting up Update Process
Resolving Dependencies
--> Running transaction check

How do I get rid of this warning /error under RHEL 6 server?