apple os x HowTo - Linux / Unix Q & A from nixCraft

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

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

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?

Linux / Unix: Use rsync Command Over FTP

last updated April 9, 2013 in Linux, UNIX

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

last updated January 26, 2017 in Amazon Cloud Computing, Linux, Mac OS X, OpenBSD, Suse, Troubleshooting, UNIX

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 root@ec2-xx-yy-zzz-yyy.compute-1.amazonaws.com

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?

Linux / Unix Bash Shell List All Builtin Commands

last updated January 25, 2018 in BASH Shell, Linux, UNIX

Builtin commands contained within the bash shell itself. How do I list all built-in bash commands on Linux / Apple OS X / *BSD / Unix like operating systems without reading large size bash man page?

Linux / Unix Find Command Avoid Permission Denied Messages

last updated January 13, 2019 in BASH Shell, Linux, Troubleshooting, UNIX

When I type find . -type d -name "foo" command I get Permission denied error messages. How do I exclude all “permission denied: messages from the find command under Linux or Unix like operating systems?

HowTo: Use pwd Command In Linux / UNIX

last updated March 10, 2013 in Commands, Linux, UNIX

How do I use the pwd command in Linux or Unix like operating systems? How can I use pwd command in UNIX or Linux shell scripts for automation purpose?

Linux / Unix: Unicode and HTML Characters Lookup By Name or Number

last updated December 4, 2012 in Gnome, kde, Perl

I need to replace special characters with equivalent hexadecimal unicode under Linux or Unix like operating system. How do I list or find out unicodes for given characters?