cat command

I see lots of seasoned admins and cloud provider wrapper scripts use ssh client command as follows in shell:

ssh --

What the double -- does here? Why it is used in this shell command and why not just use the following?



I know how to display line numbers using vim text editor. How do display line numbers in the left side for any text file under Unix or Linux operating systems?

{ 1 comment }

How do I concatenates the text files called first.doc and second.doc and writes the result to final.doc under Ubuntu Linux operating systems?


I am new Linux and Unix-like system user who recently switched from MS-Windows XP. How do I save the output of a Linux / Unix ls command to a file named “lists.txt” using command prompt or POSIX shell such as SH/KSH/BASH?


How do I use the cat command to display the line numbers for a file called myapp.c under Linux or Unix like operating systems?

{ 1 comment }

I am a new Unix user. I have Debian Linux installed. I need to append text to a file called daily.log. How do I use the cat command to append data to a file?


I have followed this cron setup tutorial. I am using Red Hat Enterprise Linux server 6 on Dell poweredge server. I would like to know when does entires in /etc/cron.daily, /etc/cron.weekly, /etc/cron.monthly run on RHEL6 and Debian / Ubuntu Linux server?