Szesnaste_21

check if packages coming from outside repo are allowed in inside repo

gpgcheck

What is the input in. repo saying about certificate?

gpgkey

show enabled repos in the system

yum repolist

hows all repos in the system

yum repolist all

How to add repo automatically?

yum-config-manager --add-repo=http://URL to repo

How to disable repo?

enabled = 0 // yum-config-manager --disable <repoId>

How to perform obtaining GPG key and installation in the system?

Go to the site where GPGs are available, i.e. Fedora, download gpg-key and put it in /etc/pki/rpm-gpg, copy to /etc/pki/rpm-gpg/nazwa_gpg, add gpgcheck=1, add pgpkey=file:///etc/pki/rpm-gpg/nazwa_gpg

Displays info about Kernel?

uname -r

Info about installed kernel and what can be downloaded

yum list kernel

Update kernel automatically

yum update kernel

update kernel from. rpm:

1) yumdownloader kernel, 2) yum install linux-firmware, 3) rpm -ivh new_kernel. rpm

How to boot system with different kernel?

grub2-set-default 1

Replace word hello with word world with sed command

sed -i 's/hello/world/' file. txt

Replace every occurrence of Nick with John in report. txt

sed 's/Nick|nick/John/g' report. txt

Add 8 spaces to the left of a text for pretty printing.

sed 's/^/ /' file. txt >file_new. txt

Display only one paragraph, starting with "Of course" and ending in "attention you pay"

sed -n '/Of course/,/attention you \ pay/p' myfile

Show only lines 12-18 of file. txt

sed -n 12,18p file. txt

Show all of file. txt except for lines from 12 to 18

sed 12,18d file. txt

Double-space file. txt

sed G file. txt

Write all commands in script. sed and execute them

sed -f script. sed file. txt

Replace ham with cheese in file. txt except in the 5th line

sed '5! s/ham/cheese/' file. txt