Linux study guide

From WikiPaul - Paul Swanson's wiki

Contents 1 Networking 1.1 etc 2 Software management 3 Jobs 4 Scheduling 5 Sharing 6 Startup 7 Logs

Hello, CIOS212! Feel free to edit this page to add stuff. So long as it's right. :)

Networking

ifconfig	shows all
ifconfig eth0 10.10.0.1
ifconfig eth0 (|-)multicast
iptables
/etc/sysconfig/iptables	configuration
/etc/sysconfig/network-scripts
/etc/sysconfig/ifcfg-eth0
neat, system-config-network
route	show/manage routes
netstat	active internet connections
service network (stop|start|restart)

etc

/etc/hosts	Give IP addresses a local name (localdns)
/etc/resolve.conf	nameserver/dns host
/etc/hosts.(allow|deny)	host based restrictions
/etc/hosts.conf	domain name resolution
/etc/services	port assignments - protocols/names/port
/etc/hosts	IP address - name

Software management

rpm	a package manager
source
rpm -i <package>	install
tar xf <file>.tar(.gz|.bz2) && cd <file> && ./configure && make && sudo make install
rpm -e <package>	erase
rpm -q <package>	query
rpm -qa	all
rpm -q --filesbypkg <package>	what files come from which package
rpm -q --whatprovides /path/to/file	what package provided file
rpm -U <package>	Update

Jobs

jobs	show backgrounded jobs
ctrl+z	suspend
bg	resume suspended jobs in the background
<command> &	start in background
ctrl+c	sends term interrupt signal
ctrl+d	sends EOF character
fg <job id>	foregrounds job id
kill	sends a term signal to a process
killall	kills processes by name

Scheduling

cron	processes recurring scheduled events
crontab -(l|e|)	list, edit, or remove scheduled tasks
MAILTO=fspas10
SHELL=/bin/bash
Minute Hour Dayofmonth Month Dayofweek Command
5 * * * * rm -rf ~/temp	every five minutes, delete your temp directory
*/5 * * * * cat /dev/urandom > ~/owned.txt	every fifth minute
6-14 * * * * echo hi	every minute between and including 6 and 14

Sharing

• nfs
• samba
• ftp

	NFS	Samba	FTP
Connect command	mount	smbclient	ftp
Other commands	bash shell	list/connect	get/put
Use	unix sharing	Windows sharing	any host
Files	/etc/exports	/etc/samba/smb.conf	/etc/vsftp/vsftpd.conf

• service nfs restart

Startup

/etc/inittab
/etc/rc<runlevel>.d (/etc/rc3.d)
Files in ^ are links to /etc/init.d/
S - start
K - kill
number - priority
init <runlevel>	changes your current runlevel to <runlevel>
service	manages services in /etc/init.d/
chkconfig -list	list all
chkconfig --level <level> <name> on|off|reset

Logs

/var/log

*/messages

*/seruce

*/anacron

*/maillog

*/boot.log

syslog

/etc/syslog.conf

/etc/syslog.d/

logrotate

/etc/logrotate.conf

/etc/logrotate.d