What do you need to do before you can perform SSH passwordless logins?

When installing a downloaded package on the RedHat-based distribution manual using RPM, what may you have to do first?

With GNU tools such as a GNU grep, awk, and sed, what is the difference between basic regular expressions (BREs) and extended regular expressions (EREs)?

What is the difference between reading the list of disk partitions from /proc/partitions and getting it using fdisk -l?

What would be in out.txt?

Using alternation in a POSIX-extended regular expression, which numbers would this pattern match? ^(([0-9][0-9]?)|(2[0-9][0-9]))$

Ubuntu is based on...

Fedora Linux uses _____ packages.

Executing 'pwd' in shell will return:

How do you activate the noclobber shell option?

'mkfs' is used to: