My Technical Handbook: Linux commands

Hotkey / Redirection

Exit X window / Test Hang .......... : Ctrl + Alt + Backslash
Alternate from X window to Terminal .......... : Ctrl + Alt + F2..F6 .. ( Reserse to Xwindow : Ctrl + Alt + F7 )
New Login........... : Ctrl + Alt + F3
Reboot........... : Ctrl + Alt + Del
Memory ........... : Shift + ScrollLock
Prompt ........... : Alt F2
Stop Hang ........... : Alt F2 , Alt F3
Redirect Output ........... : > (such print screen to file $cat > filex )
Redirect Input ........... : <
Redirect Addition to file : ........... : >>
Forget Root Password ( Boot Single )
At LiLo Prompt / Boot with Floppy , wait for prompt
Type command ........... : linux single

--------------------------------------------------------------------------------

Basic Admin

check Server Name / Distribution /Dist Name / Kernel / Prcessor : telnet x.x.x.x (Only name : hostname )
Date of Installed .......... : uname -a
Check Resoource :

Cup / Mem / Swap ..........: top
Memory only ...........: free
Disk Space ............: df
Who Using console ..........: whoami
Broadcast for user who connected this host ...........: wall 'Server will down in 5 mins ..admin'
log Reboot / UsrLogin / Ftp /Telnet ...........: last | more
log size check ..........: du log /var
File Content ............: cat filename
File count line ...........: cat filename | wc -l
file type ..........: file <filename>
Show some content in file ( head / tail ) ..........: head filename ( show 5 line in head : -n 5 )
Shell User changing ..........: su
Shell check ..........: echo $SHELL ( list : chsh - l, change shell : chsh )
Sort Content in file ..........: sort filename
Print Manpage ...........: man -t bash > man.ps ( nroff -> postscrip , ps2ascii for postscrip -> txt )
Text to PDF.......... : software in Mr.Linux
Restart Inittab ..........: init q or kill -HUP 1

--------------------------------------------------------------------------------

Help / Log

search command : keyword <tab>
Search Description : whatis keyword
Command Description & Useage : man keyword
Command Usage : keyword --help

linux Messages show

tail -f /var/log/messages | grep ...

tail /var/log/messages
less /var/log/messages
more -f /var/log/messages
vi /var/log/messagesOutput:

Common Linux log files name and usage

/var/log/message: General message and system related stuff

/var/log/auth.log: Authenication logs

/var/log/kern.log: Kernel logs

/var/log/cron.log: Crond logs (cron job)

/var/log/maillog: Mail server logs

/var/log/qmail/ : Qmail log directory (more files inside this directory)

/var/log/httpd/: Apache access and error logs directory

/var/log/lighttpd: Lighttpd access and error logs directory

/var/log/boot.log : System boot log

/var/log/mysqld.log: MySQL database server log file

/var/log/secure: Authentication log

/var/log/utmp or /var/log/wtmp : Login records file

/var/log/yum.log: Yum log files

--------------------------------------------------------------------------------

Xconfig / VGA

Xwindow need : ntsysv , On xfs Service

VGA & Resolution Tool : DarkConf
Show Current Config : Xdrakres
Vga & Monitor Setup : Xconfigurator
Exit Xwindow / Test Hang : Ctrl + Alt + Backslash
Xremote :

$xhost +
$export DISPLAY=192.168.20.Client:0.0

General Set :

Monitor : Generic / Super VGA 1024 x 768 87 Hz
monitor2 : Extended super vga , 800 x 600 at 60 Hz
Resulation : 16 million color (24bit) 800 x 600

--------------------------------------------------------------------------------

Chek Version

Check kernel version ........: kernelversion
Check Distribution Kernal : uname -a , uname -r
Check Distribution Version : rpm -qa | grep
Check Server Name ..........: uname -a
Check Shell .....................: kviewshell -v

--------------------------------------------------------------------------------

Hardware , Cpu-chip , Device , IRQ , Disk Performance , Distribution Version .

Check Hardware & another .................................................... : dmesg | more ( from /var/log/dmesg )

linux cpu type...................................................................... : cat /proc/cpuinfo

Find the speed of Ethernet card ............................................. : dmesg |grep eth0

Find the speed of Ethernet card ............................................. : ethtool eth0

List PCI Devices .................................................................. : lspci
Drop Caches ....................................................................... : echo 1 > /proc/sys/vm/drop_caches

Drop Caches ....................................................................... : echo 2 > /proc/sys/vm/drop_caches ( To free dentries and inodes )

Drop Caches ....................................................................... : echo 3 > /proc/sys/vm/drop_caches ( To free pagecache, dentries and inodes )

Accessories

--------------------------------------------------------------------------------

Set Date Time : timeconfig , linuxconf

Set Time and Date

date -s "7/12/2009 08:38:05" -- "mm/dd/yyyy hh:mm:ss" rdate -s time-a.nist.gov

--------------------------------------------------------------------------------

Disk / Mounting

Check disk performance :

dmesg | more ( raid 5 )
hdparm -t -T /dev/hdx ( adjust speed : hdparm -c /dev/sda5 )

Check free disk ...............................: df
Check Disk Use ( dir / s ) .................: du | more ( du -h | tail -n 1 )
Check Bad Block ..............................: e2fsck -c /dev/sda5
Check & admin IDE ..........................: hdparm -parameter
Manual Fix .......................................: fsck -y /dev/hda1
Format Disk .....................................: mke2fs /dev/hdb2
Mount CD-ROM..................................: mount /dev/cdrom /cdrom or mount -t iso9660 /dev/cdrom/ /mnt/cdrom
Unmount...........................................: unmount /mnt/cdrom
Modify Partitiontable ..........................: fdisk
Add Second IDE :

fdisk /dev/hdb ... ( not hdb1 )
press p ............................................... look for exist partition
press d ............................................... delete the old partition on disk
press m .............................................. for menu help ( p = look partition , n = create new partition , d = delete partition )
after clear disk to space press n............. for create new partition
Select primary partition ........................ ( not extend partition )
enter for start and end number of cylinder.. ( use default incase one partition )
press w and then press e .......................... for save and exit
$mke2fs /dev/hdb1 .................................. format ext2
$cd / and $mkdir /data............................ create directory support
$mount -t ext2 /dev/hdb1 /data ................ mount to directory
edit /etc/fstab add : .................................. : /dev/hdb1 /data ext2 defaults 1 2
reboot

--------------------------------------------------------------------------------

File / Directory

Compare 2 file .....................................................: cmp file1 file2
Change Dir ..........................................................: cd /etc/usr/local
Check Current Directory ........................................: pwd
Check Size of Directory .........................................: du ( unit default = kb , -m for MB )
Up one Level ........................................................: cd ..
List ( Dir ) ............................................................: ls -l , ls file* ( show include hidden file : ls -al )
List include hidden files .........................................: ls -al
print screen to file .................................................: echo > filename
Show & print to file ...............................................: <df -h> | tee filenamecd
File Symbole .........................................................: - regular , d directory , b block special , c character special , p pipe , l link
File name long ......................................................: 255 char for ext2
File Create ............................................................: echo > filename
File Type ...............................................................: cat /etc/filex
File Delete .............................................................: rm -f filename
Remove Directory....................................................: rm -r directory
Remove Directory....................................................: rm -rf directory ( if directory is not empty )
File Copy ...............................................................: cp filex /newdir
File Rename ..........................................................: mv file1 file2
File Move ...............................................................: mv file1 /newdir
File (rawrite)...........................................................: dd
File (subst) ............................................................: ln

ln -s file1 file2 ( Creates a symbolic link to file1 with the name of the file2. )

File (attrib) ............................................................: chmod
File (sort) ..............................................................: sort
File set timestamp ..................................................: touch filex
File Classify ...........................................................: file filex
Dir (mkdir) .............................................................: md dirx
Dir (deltree /Y) .......................................................: rm -rf dirx
Dir (rmdir) ..............................................................: rd dirx (Delete only empty directory)
Dir current check .....................................................: pwd
Dir change .............................................................: cd /etc
Dir up level ............................................................: cd ..

--------------------------------------------------------------------------------

Find - File/Syntax

Find text in file .......................................................: find / | xargs grep text -i
Find name about on machine ....................................: find / | grep filename
Find file in directory .................................................: ls sample*.*
Find all machine ......................................................: no commend
Find Syntax in File all machines .................................: no commend

How to find files in Linux using 'find'

find -name 'mypage.htm'

#In the above command the system would search for any file named mypage.htm in the current directory and any subdirectory.
find / -name 'mypage.htm'

#In the above example the system would search for any file named mypage.htm on the root and all subdirectories from the root.
find -name 'file*'

#In the above example the system would search for any file beginning with file in the current directory and any subdirectory.
find -name '*' -size +1000k

#In the above example the system would search for any file that is larger then 1000k.
find . -size +500000 -print

--------------------------------------------------------------------------------

User Manage

Manage User ...........................................................: userconf (user tab)
Current connect .......................................................: who
Login User reboot / ftp / telnet ..................................: last | more
Detail of Current connected user ................................: finger
Add User.................................................................: add user xxxx
Change Password ....................................................: passwd
Backup user account ................................................: /etc/passwd

Create a new user and group by:

# groupadd www-data
# useradd -g www-data www-data

What is the command to list users?

cat /etc/passwd

cat /etc/passwd |grep 500*

cat /etc/passwd | grep /home | cut -d: -f1

cat /etc/passwd | cut -d: -f 1,3,6 | grep "[5-9][0-9][0-9]"

cat /etc/passwd | cut -d: -f 1,3,6 | grep "[5-9][0-9][0-9]" | grep "/home" | cut -d: -f1

gawk -F: '{ print $1 }' /etc/passwd

--------------------------------------------------------------------------------

Permission & Owner

Permit All thing ......................................................: chmode 777 file
Change owner ........................................................: chown newuser file
Change Groupe .......................................................: chgrp newgrp file
Change Format .......................................................: chmode usr/grp/owner + rwxst file
777 rwx rwx rwx
770 rwx rwx ---
700 rwx --- ---
755 rwx r-x r-x
666 rw- rw- rw-
660 rw- rw- ---
600 rw- --- ---
555 r-x r-x r-x
400 r-- --- ---
-------------------------------------------------------------------
4 = r--
5 = r-x
6 = rw-
7 = rwx

--------------------------------------------------------------------------------

Terminal

Open New ..........................................................: xterm
Clear screen .......................................................: clear
intterupt process ................................................: ^z

--------------------------------------------------------------------------------

Run / Execution

check path ........................................................... : echo $PATH
list past command ................................................ : history

History null
#cp /dev/null /root/.bash_history

run batch file in bash shell ..................................... : ./scriptx
synchronous / forground mode (sequence statement) ..: netscape
asynchronous / background mode (not sequence statement) : netscape &
run level .......................................................................: 0 halt , 1 single , 2 multiuser no NFS , 3 multiuser , 4 nouse , 5 multiuser with X , 6 reboot

--------------------------------------------------------------------------------

Memory / Process / Services

Process Monitor .............................................................: top
Detail ..........................................................................: Shift+ScrollLock
chech free memory .........................................................: free

Swap command ..............................................................: swapon / swapoff
process Running .............................................................: pstree , ps
Process of daemon running ..............................................: ps -aux | grep daemon

Type the following command to list top 10 memory eating process Code ................ : ps -auxf | sort -nr -k 4 | head -10

Select Auto Service .........................................................:ntsysv
Restart Inittab ...............................................................: init q or kill -HUP 1

--------------------------------------------------------------------------------

Package / Application INSTALL

RPM - Package

Unzip .tar.gz ................................................................: tar -xvfz zipfile.tar.gz
Check Package Name .....................................................: ls /cdrom/RPMS | grep ppp
Check Package Path .......................................................: rpm -ql package
Check Package install .....................................................: rpm -qa | grep package (such rpm -qa | grep bind)
Install Package check dependent .....................................: rpm -ih package
Install Package no check dependent .................................: rpm -ihV package
Check version ................................................................: rpm -qa | grep package or rpm -v package
Uninstall .......................................................................: rpm -e shortname or rpm -e -allmatches --nodeps package
Uninstall force ...............................................................: rpm -e --nodeps shortname

rpm -qp vym-1.12.0.i586.rpm --requires ........................... Dependenci check

--------------------------------------------------------------------------------

Source Install

After ...........................................................................: tar -fxvz file.tar.gz
Check yourself ..............................................................: root priviledge ( no need root login )
Add this line into /etc/ld.so.conf ......................................: /usr/local/lib ... (and run $ldconfig)
Open README and read
Exist Script Install :

./install.sh (Change path in file install-sh before)
./setup.sh
install (Change install file before)

No script Install :

change path in configure , INSTALL
Create Makefile Script ( Change path in configure file before ).....................: ./configure
Change path in ....................................................................................: Makefile
Compile ..............................................................................................: make
Install ................................................................................................: make install

--------------------------------------------------------------------------------

Compression and Archival ( Zip / Tar )

Copy file to / from archives ...........................................................................: cpio
Lempel-Ziv program .....................................................................................: compress
ZIP :

Zip Directory to gz ..........................................................: tar cvf archivename.tar dir-to-archive/ ..(~Backup)
Zip Directory to gz ..........................................................: gzip new.tar
Zip File to gz ................................................................: tar cvf new.tar destinationfile

Unzip

Total one .......................................................................: tar -zxvf zipfile.tar.gz
Only gz ..........................................................................: gunzip new.tar.gz
Only tar .........................................................................: tar -ixvf zipfile.tar
Only bz2 ........................................................................: bunzip2 zipfile.tar.bz2
Use Archiver incase ..........................................................: .tgz

Option

z ................................................... : xtrace from gz
v ................................................... : view filename
z ................................................... : file target/not tape
v ................................................... : xtrace from tar

--------------------------------------------------------------------------------

Network Monitoring

Net Nic Config ....................................................................... : netconf , ifconfig , linuxconf , netcfg
Net Remote Login .................................................................. : rlogin
Net speed & physical link check ............................................... : ping x.x.x.x
Ask Nebios Name .................................................................. : nmblookup -A x.x.x.x
Ask IP-Address :

Internet ............................. : host www.myweb.com , ping www.myweb.com
Netbios .............................. : nmblookup -A server_x

Net connect established ......................................................... : netstat -n | more
Net Trace ( count router & check name ) ................................... : traceroute x.x.x.x
Net Route ............................................................................ : route [-param]
Net Masquerade Monitor ........................................................ : gfcc , netstat -m
Net Status ........................................................................... : netstat -param
Net Access ........................................................................... : netstat -m
Net User .............................................................................. : w , who (port513) , users , ftpwho , wc -l , whois x.x.x.xnet
Net Log / usrlogin ................................................................. : last | more
Net lookup DNS .................................................................... : nslookup
Net look Dhcp Leases ............................................................ : cat /var/dhcpd/dhcpd.leases
Net look Dhcp / server ........................................................... : tail -f /var/log/messages
Net look squid log ................................................................. : tail -f /var/log/squid/access.log
Net Firewall Rule Lookup ........................................................ : ipchaines -L
Net Clear Firewall Rule ........................................................... : ipchaines -F
Net Chat .............................................................................. : irc

--------------------------------------------------------------------------------

Module Concern

Module :

List Module ........................... : lsmod
By webmin ............................ : system>software package>

for Compiling

Gcc -o name.cgi name.c

--------------------------------------------------------------------------------

lsof command is used to see all the open files, just execute this command, you will get some clue which is causing issues.. #lsof

My Technical Handbook

Monday, March 7, 2011

Linux commands

Common Linux log files name and usage

List PCI Devices .................................................................. : lspci

No comments:

Post a Comment