debian – nixCraft

Linux: Hide Processes From Other Users

August 21, 2014in Linux, Security, User Management last updated August 21, 2014

I run a multi-user system. Most users access resources using ssh client. How to stop leaking process information to all users on Linux operating systems? How do I prevent users from seeing processes that do not belong to them on a Debian/Ubuntu/RHEL/CentOS Linux server?

Connect To Amazon AWS EC2 Instance From a CentOS / RHEL Using SSH Client

June 23, 2014June 23, 2014in Amazon Cloud Computing, CentOS, Linux, Openbsd, RedHat and Friends, UNIX last updated June 23, 2014

I have created/launched Amazon Machine Image (AMI) instance powered by a CentOS/RHEL/Red Hat Enterprise Linux. How can I connect to my instance using OpenSSH Linux/Unix/OSX ssh client?

Unix: Find Directory Name From Path

April 7, 2014in BASH Shell, KSH Shell, Linux, UNIX last updated April 7, 2014

I am a new Unix shell programer. How can I extract the directory name from a full path (say /nas01/data/backups/file.tar.gz)? How do I get directory name from its path on a Linux or Unix-like system?

scp: Do not Overwrite Existing File On Linux or Unix System

May 10, 2013May 10, 2013in BASH Shell, Commands, Linux, UNIX last updated May 10, 2013

I am a new Linux user. I use scp to upload files to net-storage provided CDN company. I do not want to overwrite the existing files. How can I prevent overwriting of files when using scp command under Linux, Mac OS X or Unix like operating systems?

Vi / Vim: Wipe and Undo All Changes Since Opening a File

April 28, 2013April 28, 2013in Linux, UNIX, Vim last updated April 28, 2013

I am a new vi / vim text editor user and I know how to quit without saving changes. What if I want to wipe out all of the edits I have made in a session and get back to the original file? How do I wipe all changes since opening a file?

Linux / Unix: Use rsync Command Over FTP

April 9, 2013April 9, 2013in Linux, UNIX last updated April 9, 2013

How do I use rsync command to sync files to a remote host called web-42.vps running VSFTPD ftp server? Can you give me rsync ftp example for Unix like operating systems?

SSH: WARNING: UNPROTECTED PRIVATE KEY FILE! Error and Solution

April 9, 2013January 26, 2017in Amazon Cloud Computing, Linux, Mac OS X, Openbsd, Suse, Troubleshooting, UNIX last updated January 26, 2017

I‘m setting up server on an Amazon EC2 compute instance powered by Suse Enterprise Linux server. I am using the following command to login into the my EC2 compute from OS X/Ubuntu desktop:

ssh -i suse-ec2-server-jp.pem [email protected]

I am getting the following error:
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: UNPROTECTED PRIVATE KEY FILE! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ Permissions 0440 for 'suse-ec2-server-jp.pem' are too open. It is recommended that your private key files are NOT accessible by others. This private key will be ignored. bad permissions: ignore key: suse-ec2-server-jp.pem Password:

How do I fix this problem and login using ssh command?