OpenBSD related tutorial/FAQ

How to install and configure OpenVPN client on OpenBSD

last updated June 21, 2018 in Cryptography, Networking, OpenBSD, OpenVPN

I have a file named openvpn.client.ovpn. How do I use this file to connect my OpenBSD based desktop to remote OpenVPN server and setup secure VPN? How do I configure OpenVPN client on OpenBSD Unix system?

How to patch Meltdown vulnerability on OpenBSD Unix

last updated April 20, 2018 in OpenBSD, Security, UNIX

I read that OpenBSD is the first BSD family of the operating system to release updates for its stable releases to mitigate the Meltdown vulnerability. How do I patch Meltdown on OpenBSD Unix operating system?

How to exclude file when using scp command recursively

last updated August 9, 2019 in FreeBSD, Linux, OpenBSD, UNIX

I need to copy all the *.c files from local laptop named hostA to hostB including all directories. I am using the following scp command but do not know how to exclude specific files (such as *.out):
$ scp -r ~/projects/ user@hostB:/home/delta/projects/
How do I tell scp command to exclude particular file or directory at the Linux/Unix command line?

How to check running process in Unix using command line

last updated December 27, 2018 in AIX, FreeBSD, HP-UX Unix, Linux, OpenBSD, Solaris, UNIX

I am a new sysadmin for the Unix operating system. How do I check running process in Unix using the command line option?

How to use/run bash aliases over ssh based session

last updated December 26, 2017 in BASH Shell, Linux, OpenBSD, Troubleshooting, UNIX

I have set up a bash alias named file_repl. It works entirely when I log in using ssh command. However, my bash aliases are not running over ssh, for example:
$ ssh vivek@server1.cyberciti.biz file_repl bash: file_repl: command not found
How do I run bash shell aliases when I use ssh command?

How to show recursive directory listing on Linux or Unix

last updated December 23, 2018 in FreeBSD, Linux, OpenBSD, UNIX

I am a new Linux system user. How do I see a recursive directory listing on macOS Unix system? In Linux, how can I get a recursive directory listing?

How to install keychain manager for ssh-agent on CentOS 6/7

last updated February 2, 2018 in CentOS, Linux, OpenBSD, Package Management, RedHat and Friends

OpenSSH offers RSA and DSA authentication to remote systems without supplying a password. keychain is a special bash script designed to make key-based authentication incredibly convenient and flexible. It offers various security benefits over passphrase-free keys. How do I install keychain on a CentOS Linux 6.x or 7.x?

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