Bash Generate UUID in bash Sometimes you may need to generate random UUIDs in bash shell. Here's a quick way to generate one : uuidgen If you need to get just the uuid and no dashes , you can use sed : uuidgen | sed 's/-//g' Another way to use the kernel random uuid cat /proc/sys/
Linux Getting exit status of the command when using pipes I came across a situation where i needed the exit code of last command but before passing it through the pipe. For example, running the following command would give the exit code 0, even if the first command failed : root@NTRTR:/tmp# wl -i eth0 assoclist | wc -l wl: wl
alpine linux Alpine with XFCE and VNC on a virtual machine I was looking to create a light weight virtual machine with Graphical user interface for segmenting some of my internet browsing endeavors. I tested a couple of light weight Linux distros but ended up with just using Alpine Linux with XFCE as the Desktop Environment and VNC for remote access.
nginx Nginx - SSL Passthrough Reverse Proxy Nginx 1.9.3+ allows TCP load balancing or SSL passthrough. What this means is you can reverse proxy or load balance web applications without having to terminate SSL at the nginx. Example Configuration for name based access: stream { map $ssl_preread_server_name $name { www.somesite.com some-server; www.
Bash Touch command tips and tricks Changing modification time using touch: touch -d '-4 day' filename touch -d '-4 hour' filename touch -d "30 days ago" filename Setting Timestamp : touch -t 201606101712 filename
Linux Disabling SELINUX In order to disable selinux , run the following commands : To Disable SeLinux For Current Session only : setenforce permissive or echo 0 > /selinux/enforce To Disable Selinux permanently: vi /etc/sysconfig/selinux SELINUX=disabled
Linux Configure PPTP VPN Server 1. Install ppp yum install ppp 2. Download pptpd rpm wget http://poptop.sourceforge.net/yum/stable/packages/pptpd-1.3.4-2.el6.i686.rpm 3. Set the local and remote ip in /etc/pptpd.conf vi /etc/pptpd.conf localip remoteip < range of ip addresses to be assigned to users,
Linux Extending an LVM With FreeSpace There can be a number of scenarios you want to extend an LVM. a. New Hard Drive b. Free Space c. Extended disk in a VM If you just extended space, you have that as raw filesystem. So just open fdisk and create new partition and start working on the
Linux Installing Mono Tools in Centos Mono tools are the collection of libraries and framework , that make the possibility of using .net based applications and gui in linux. They are not available in the standard repositories, so we have to create a repo : vi /etc/yum.repos.d/mono.repo [mono] name = novell-mono baseurl=http://ftp.
firewall Redirect or forward ports in iptables Redirect or Forward Ports using Iptables Port Redirection: iptables -t nat -A PREROUTING -i -p tcp --dport -j REDIRECT --to-port or iptables -t nat -I PREROUTING --src ip/mask --dst -p tcp --dport 80 -j Redirect --to-port Port Forwarding: iptables -A PREROUTING -t nat -i -p tcp --dport 80 -j
Linux Set Time zone In Linux Setting Desired Time Zone In Linux View the list of available Timezones: ls /usr/share/zoneinfo cd /etc/ mv localtime localtime.old ln -sf /usr/share/zoneinfo/GMT localtime /sbin/hwclock --systohc``` Sometimes, the above method does not work, this is probably caused by corrupt Time zone data. Reinstalling the
