Category Archives: Linux

Generate SSL CSR (Certificate Signing Request) from Command line without prompt

CSR with special chars? Add -utf8 to the openssl command If connecting via Putty set Windows Translation Remote character set to UTF.8 Without multiple DNS names: With multiple DNS names: Verify the CSR file: Verify the certificate file: For more information: HowTo: Create CSR using OpenSSL Without Prompt (Non-Interactive) Provide subjectAltName to openssl directly on… Read More »

CentOS 8 Install Guide

On the install GUI select minimal install After making a CentOS 8 minimal install and boot up for the first time. Here are, in my view, the tools and “must do” things that you will need for day to day work. Remove Intel Wifi devices firmware (do this only if you don’t use it): Update… Read More »

Install and setup CentOS7

After making a CentOS 7 minimal install and boot up for the first time. Here are, in my view, the tools and “must do” things that you will meed for day to day work. Remove Intel Wifi devices firmware (do this only if you don’t use it): yum remove iwl* Update CentOS to the latest… Read More »

Instalar as vmware tools via rpm

O vmware é um dos sistemas de virtualização mais utilizados a nível profissional. Ao instalar um vm CentOS 6.x no vmware é necessário instalar um conjunto de drivers para que o SO funcione de forma integrada com o hipervisor. Essas ferramentas chamam-se vmware-tools. Para instalar as vmware-tools via rpm é necessário realizar os seguintes passos:… Read More »

Send email from Linux command line

Every once a while you need to send email from a Linux command line and there you go to google try to find it… With attachment: Without attachment: Important:Postfix by default restrict attachment size to approx 10MB i.e. 10240000 bytes. You can check it using following command: To change attachment-size to say 50 MB, run… Read More »

Install Java SE Development Kit 7u40 on CentOS 6.4

Installing JDK on CentOS can be hard, so to help you I’ve made this simple tutorial. Hope it helps… Download and install: Go to http://www.oracle.com/technetwork/java/javase/downloads/index.html an select JDK Download. Install JDK: [cc lang=”bash” width=”100%”] rpm -ivh /path-to-file/jdk-7u40-linux-i586.rpm [/cc] And set it up: [cc lang=”bash” width=”100%”] alternatives –install /usr/bin/java java /usr/java/latest/jre/bin/java 20000 alternatives –install /usr/bin/javaws javaws… Read More »

SSL Certification Authority on Linux

SSL Certification authority In cryptography, a certificate authority, or certification authority, (CA) is an entity that issues digital certificates. The digital certificate certifies the ownership of a public key by the named subject of the certificate. This allows others (relying parties) to rely upon signatures or assertions made by the private key that corresponds to… Read More »