Linux / unix in 60 minutesOr so I hope . . . .

1

Unix Conceived and implemented in 1969 at AT&T Bell Labs First written in assembly, but then re-written in C by Dennis

Ritchie Because it was now available in a “high level” language it

was more easily portable It took off in Industry & Academia Several flavors: System V, Berkeley (BSD), Sun OS But all had licensing issues Linus Torvalds decides to create an open-source version in

1991

Linux History

First – Help you help yourself man (“See Also”, “Examples”) locate apropos

Let’s get started . . . .

pwd ls

ls –l ls –la ls -ltr

cd cd .. cd ~

Moving Around

cat more less grep

grep –v find tail

Reading Files

cp mv rm

rm -r rm –rf (Be REALLY careful!)

mkdir rmdir tar

tar -xvf tar –cvf tar -tvf

chmod chown compress bzip gzip wc

wc –l wc –c

Manipulating Files

| (Pipe) ls -la | more tail -f server.log| grep –v INFO

> (overwrite) grep ERROR server.log > err.log

>> (append) grep ERROR server.log >> err.log

Pipes and Filters

ps ps –elf ps –eLf

top nohup & ctrl-z fg bg kill Left as a exercise for the user

nice cron

Processes

CPU top (again!)

Virtural memory vmstat

Disk I/O iostat

Disk Usage df –k / df -h du

Memory (Do NOT rely on ‘top’) dmesg | grep Memory

Performance

ping wget host dig netstat iptables tcpdump telnet port X ssh/ssh <command>/scp/

Connectivity

uptime date whoami w hostname uname -a

System stuff

set export echo history

!! !ls !2

su/sudo which clear command line completion (<TAB>)

Other stuff

from each other . . . .

Best way to learn

Linux Cheat Sheetshttp://www.scottklarr.com/topic/115/linux-unix-cheat-sheets---the-ultimate-collection/

20 Linux System Monitoring Tools Every SysAdmin Should Knowhttp://www.cyberciti.biz/tips/top-linux-monitoring-tools.html

Understanding Memory Usage on Linuxhttp://virtualthreads.blogspot.com/2006/02/understanding-memory-usage-on-linux.html

Linux: How to measure actual memory usage of an application or process?http://stackoverflow.com/questions/131303/linux-how-to-measure-actual-memory-usage-of-an-application-or-process

RHEL 5 Essentialshttp://www.techotopia.com/index.php/RHEL_5_Essentials

References