บรรทัดคำสั่งพื้นฐาน
- สำหรับเราเอง เขียนไว้กันเหนียวเผื่อลืม
- อย่าเชื่อมาก ต้องลอง
What is command line ?
- One interface with linux os for linux user.
What is shell ?
Why should know command shell ?
- Can work on every linux distribution.
- Every nix base it's same command (little bit diff).
- Windows have a plan to change dos command to compatible with linux.
- Easy to work with.
- Any way, Command-line interface is faster (Comfirm by jui ^^' so really)
Terminal structure (teletypewriter)
- tty1 to tty7 (Desktop)
- By press Ctrl + Alt + F1 to F7
Linux file system
- in linux don't have drive every drive is folder
- / call "root" is top of directory in linux file system
- /bin : essential binaries
- /boot : static files of boot loader
- /etc : host specific system config
- /usr : shareable and read-only data
- /var : variable data files
- /sbin : system binary
- /tmp : temporary files delete on bootup
- /dev : location of special or device files
- /home : user home directory
- /lib : library and kernel modules
- /media : mount files
- /opt : add-on application software
- /root : home of root
Command prompt
- username@hostname:~$
- "username" is user in linux system
- "hostname" is computer name
- "~" working directory
- "$" is permission (and # for root)
Command-line pattern
- [command]
- [command] [option]
- [command] [option] [file or path]
- [command] [file or path] [option]
- [command] [option] [file or path] [file or path2]
Special path
- "." is current directory
- ".." is parent directory
- "~" is home directory
File of linux system
- File
- Hidden file
- Directory
- Link
Help for linux by
- "man"
- "--help"
### File command
$ ls -la => directory listing with hidden files
$ cd dir => change directory to dir
$ cd|cd ~ => change to your home
$ pwd => print work directory for show current directory
$ mkdir dir => create directory dir
$ rm file => remove file
$ rm -r dir => remove directory dir
$ rm -f file => force remove file
$ rm -rf dir => force remove dir
$ cp file1 file => copy file1 to file2
$ cp -r dir1 dir => copy dir1 to dir2, create dir2 if it doesn't exist
$ mv file1 file2 => rename or move file1 to file2 if file2 is an existing directory, moves file1 into directory file2
$ ln -s file link => create symbolic link link to file
$ touch file => create or update file time stamp
$ cat file => output the content of file
$ cat > file => places standard input into file instead text editor ^^' and stop by ^c (^ is ctrl)
$ cat file1 > file2 => copy content in file1 replace to file2 if files is an existing
$ cat file1 >> file2 => copy content in file1 append to file2 if files is an existing
$ more file => output the content of file each page
$ less file => output the content of file and can go to next or previous page
$ head file => output the first 10 lines of file
$ tail file => output the last 10 lines of file
$ div file1 file2 => output difference content between file1 and file2
### Searching
$ grep pattern files => search for pattern in files
$ grep -r pattern dir => search recursively for pattern in dir
$ grep ^pattern files => search begin by pattern
$ command | grep pattern => search for pattern in the output of command
$ locate file => file all instances of file
### Process management
$ ps => display your currently active processes
$ ps -aux => display any your currently processes
$ top => display all running processes and change display every 1 sec
$ htop => third party program same 'top'
$ kill pid => kill process id pid
$ killall program => kill all processes named proc (use with extreme caution)
$ bg => lists stopped or background jobs; resume a stopped job in the background
$ fg => brings the most recent job to foreground
$ fg n => brings job n to the foreground
$ /etc/init.d/serv start|stop|restart|reload => for start stop service
### Shortcuts
$ Ctrl+C => halts the current command
$ Ctrl+Z => stops the current command, resume with fg in the foreground or bg in the background
$ Ctrl+D => log out of current session, similar to exit
$ Ctrl+W => erases one word in the current line
$ Ctrl+U => erases the whole line
$ Ctrl+R => type to bring up a recent command
### System info
$ clear|reset => clear screen
$ echo pattern => display pattern
$ time command => use how long work with command
$ date => show the current date and time
$ cal => show this month's calendar
$ uptime => show current uptime
$ w => display who is online
$ whoami => who you are logged in as
$ finger user => display information about user
$ uname -a|r => show kernel information
$ cat /proc/cpuinfo => cpu information
$ cat /proc/meminfo => member information
$ man command => show the manual for command
$ df => show disk usage
$ du => show directory space usage
$ free => show memory and swap usage
$ whereis app => show possible locations of app
$ which app => show which app will be run by default
### Compression
$ tar cf file.tar files => create a tar named file.tar containing files
$ tar xf file.tar => extract the files from file.tar
$ tar czf file.tar.gz files => create a tar with Gzip compression
$ tar xzf file.tar.gz => extract a tar using Gzip
$ tar cjf file.tar.bz2 => create a tar with Bzip2 compression
$ tar xjf file.tar.bz2 => extract a tar using Bzip2
$ tar tf|tvf file.tar|.gz|.bz2 => display content in zip file
$ gzip file => compresses file and rename it to file.gz
$ gzip -d file.gz => decompresses file.gz back to file
### Network
$ ping host => ping host and output results
$ whois domain => get whois information for domain
$ dig domain => get DNS information for domain
$ dig -x host => reverse lookup host
$ wget file => download file
$ wget -c file => continue a stopped download
$ ssh|telnet user@host => remote host
$ ftp|sftp host|user@host => remote ftp host
$ scp file user@host:path => copy file to remote host dont' forget (:) after remote host
=> scp file user@host ,incorrect ,it only copy file to file name user@host
$ scp user@host:file file => copy file from remote host
Example:
$ scp file1 user@somehost:/opt => copy file1 to /opt of remote host
$ scp user@somehost:/opt/file1 ./ => copy file1 from remote host to current dir of local host
### Installation
$ Install from source:
./configure
make
make install
$ dpkg -i pkg.deb => install a package (Debian)
$ dpkg -l => display installed package in system
$ dpkg -l program => display program info
$ apt-cache search program => for search program
$ apt-cache show program => for show detail of prog and dependent library
$ sudo apt-get install program => install program
$ sudo apt-get update => update package repository
$ sudo apt-get upgrade => upgrade program in system
$ sudo apt-get remove program => remove program
$ sudo apt-get build-dep prog => only install dependent package of program
$ rpm -Uvh pkg.rpm => install a package (RPM)
$ rpm -ivh pkg.rpm => same install package
$ rpm -evh pkg => erase package pkg
* option 'vh' for display percent while processing of command
### File permissions
$ chmod octal file
=> change the permissions of file to octal
,which can be found separately for user,group
, and world by adding;
4 - read (r)
2 - write (w)
1 - execute (x)
Examples:
$ chmod 777 => read, write, execute for all
$ chmod 755 => rwx for owner, rx for group and world
$ chmod ugo+|-rwx => u = owner, g = group , o = other
$ chown user.group file => change to another user and group
For more options, see man chmod
### Forward output and something special
- ";" => run command finished can run command2 automatic by use ';'
Example:
$ chmod o+w file1 ; chmod o-rx file1
- "`" => is call 'backtrix' sinagure
Example:
$ passwd `whoami` => for change password current user logined
$ apt-get install linux-headers-lbm-`uname -r`-xen
$ !! => repeates the last command
- "&&" => same ";"
- "&" => run program finished and can do any thing with that shell
Example:
$ gclctool & => run calculator and can use that shell to any thing
- ">" => forward output
Example:
$ ls -l > file1 => output of ls -l overwirte into file1 if exist file1
- ">>" => forward output append
Example:
$ ls -l >> file1 => output of ls -l append into file1 if exist file1
- "\" => use in long command
Example:
$ chmod o+w file1 \
;chmod o-rx file1 \
;chmod o+rx file1
- "<" => don't explain ^^' it reverse with ">"
Example:
$ mysql user < file1 =""> for check md5sum
- 0|1|2 => get type of output 1 is valid output, 2 is error output , 0 all output
Example:
$ ./configure 2> file => for get only error output into file
### Application and Utility
$ lsusb|lspci => display device usb or pci type
$ fdisk => display disk device
$ mount|unmount => mount partition
Example:
$ mount -a => mount all device in /etc/fstab
$ script file => use record keylogger and press ^D for stop
$ ttyrec file => third party program same 'script' it for record keylogger
$ ttyplay file => display file so create by ttyrec
$ alias 'alias=command' => for create alias instead long command
Example:
$ alias 'll=ls -l'
$ unalias alias => cancel alias name
Example:
$ unalias ll
$ chroot => program for change eviroment for work
Sample chroot: when u use live cd if u must to use enviroment real system
Useful chroot: use chroot in live cd to correct real enviroment system but u must know path for config file
$ history => for display all old command
### Administration tools
$ sudo|gksudo => became to root and do it
note: edit permission sudo config file /etc/sudoers
$ su => switch to root
$ sudo visudo => can use this command only debian base
$ shutdown -h now|poweroff => shutdown machine can can define time for shutdown by number minute instead "now"
$ shutdown -r now|reboot => for reboot machine can define time for rebott
- setting ip /etc/network/interface
- setting dns /etc/network/resolve.conf
- cron , crontab
Example:
$ crontab -l => list task in cron of current user
$ crontab -e => for edit cron can see detail in wiki enter * 5 char , * is every day)
$ sudo crontab -e => crontab for superuser mode
note: if for some command need permission root , solve by crontab -e by sudo sample 'sudo crontab -e'
# .---------------- minute (0 - 59)
# | .------------- hour (0 - 23)
# | | .---------- day of month (1 - 31)
# | | | .------- month (1 - 12) OR jan,feb,mar,apr ...
# | | | | .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# | | | | |
* * * * * command to be executed
Example:
$ crontab -e
* * * * * touch ~/test-cron.txt
$ sudo adduser|useradd user => add user i recommened 'adduser' it will be create home for user
$ sudo deluser user1 => remove user
note: u can check exist user by "ls /home"
### Text editor
- pico , nano
- vi stantdard editor in unix system
- searching => default mode type '/word', press n|shift+n for find next and previous
- delete line => default mode type 'dd'
- save file => default mode ':w file'
- exit file => default mode ':q!'
- save and exit => default mode ':wq file'
- go to line => default mode n+Shift+G => n is number of line to go
Note: '=>' = mean
Related Post:
References:
