Followings are the Principal Linux Command line in alphabetical order. Hopefully this will meet your linux command need. If not please report to me. Thanks in advance.
• tac – print file in reverse
• tail – displays the last part of a file
• talk – visual communication program that copies lines from one terminal to that of another user
• tar – file compression and archiving utility. I find the syntax of this command to be frustratingly opaque. The following works for me. To use this command to unzip gzipped tarballs in verbose mode, use
o tar -xvzf filename.tgz
To create a tarball from files in a given directory and its subdirectories, use
o tar -cvzf filename.tgz sourcename
Sourcename can be the name of a single file, a wildcard such as *, or the name of a subdirectory. There seem to be two different conventions concerning gzipped tarballs. One often encounters .tar.gz. The other popular choice is .tgz. Slackware packages use the latter convention. The command can also be used to archive a file, a group of files, or a directory (with its subdirectories) on tape or onto floppies. If the material to be archived exceeds the capacity of the backup medium, the program will prompt the user to insert a new tape or diskette. Use the following command to back up to floppies:
o tar -cvf /dev/fd0 filename(s) or directoryname(s)
The backup can be restored with
o tar -xvf /dev/fd0
Tar can be used for other things. To mirror all the files and subdirectories in from-stuff to to-stuff, use the commands
o cd from-stuff
o tar cf – . | (cd ../to-stuff; tar xvf -)
No tar file is ever written to disk. The data is sent by pipe from one tar process to another. This example is taken from Running Linux, p.177. To list the table of contents of a tar archive, use
o tar tvf tarfile
To extract individual files from a tar archive, use
o tar xvf tarfile files
where files is the list of files to extract. When extracting files, tar creates missing subdirectories underneath the current directory in which the cammand is invoked.
• tcl – scripting language
• tcsh – extended version of the C shell
• tee – copy standard input to standard output and one or more files
• telinit – used to change run level. Exact run level that corresponds to single-user, multi-user, and X levels depends on distribution.
• telnet – remote login over network
• test – evaluates an expression or compares arguments. This is a shell builtin in bash, tcsh and zsh.
• tftp – user interface to TFTP protocol
• time – displays times for the current shell and its children. This is a shell builtin. Strange, because there is also a /usr/bin/time program on my Red Hat system.
• tin – Netnews reader
• tkdesk – graphical desktop file manager for X
• tksysv – graphical runlevel editor under Red Hat. Allows root to configure the services that are started at each run level.
• tload – display system load average in graph format
• top – dynamically displays process status
• touch – update access and modification times of a file. If the file does not exist on disk, an empty file is created.
• tr – translation utility that can be used, for example, to replace specified characters in a text file
• trap – traps a signal. This is a shell builtin.
• true – null command that returns a successful exit status
• tset – initializes terminal
• tty – shows special file that represents your terminal. Displays the terminal pathname.
• type – displays how each argument would be interpreted as a command. This is a shell builtin.
• typeset – declares attributes for a variaable (same as declare). This is a shell builtin.
• ul – translate underscores to underlining
• umask – establishes the file-creation permissions mask. Usage is
o umask xyz
The system subtracts x, y and z from the owner, group and other file permissions that it would otherwise assign to new files. This is a shell builtin.
• umount [device] – finish writing to the device and remove it from the active filesystem. The command umount -a will (re)mount all file systems listed in /etc/fstab.
• unalias – remove name previously defined by alias. This is a shell builtin.
• uname – displays information about the system. With no arguments, it displays the name of the operating system. With the -a option, it displays information about the operating system, the host name, and hardware.
• uniq – displays lines of a file that are unique
• unset – removes a variable or function. This is a shell builtin.
• unzip – uncompress files compressed with the zip utility, compatible with DOS PKzip
• updatedb – update file database used by locate command
• uptime – shows the time, how long the system has been up, the number of users, and average load.
• useradd – same as adduser
• userdel – remove an account (as root). The user’s home directory and undelivered mail must be dealt with separately.
• users – prints list of users on the system
• vdir – variant of the GNU version of the ls command. Defaults to printing out the long version of directory entries.
• vi – standard screen oriented Unix editor
• view – vi in read-only mode
• vim – improved vi editor
• vrfy – query remote host to verify the accuracy of an email address
• w – display info about userids and active processes
• wait – waits for a background process to terminate. This is a shell builtin.
• wc – displays number of lines, characters and words in a file
• Wharf – the AfterStep application dock module
• whatis – display one-line summary of specified command
• whereis – use to find utilities in standard locations
• which – used to find utilities in search path. Will return the absolute directory path of the named utility program.
• who – display information about currently logged in userids
• whoami – display information about userid that is currently logged in
• wish – front end to tk, an X window extension of tcl
• workbone – console based cd player
• workman – graphical cd player program
• write – send messages to another local user
• X – starts up the X server. Can be invoked with
o X -quiet -query remotemachineaddress
in order to get a graphical login screen on the remote machine. See the discussion in connection with xdm below.
• xadm – display advanced power management BIOS information
• xargs – converts standard output of one command into arguments for another. This is one of those powerful but obscure commands. Xargs reads arguments from the standard input, delimited by blanks (which can be protected with double or single quotes or a backslash) or newlines, and executes the command (default is /bin/echo) one or more times with any initial-arguments followed by arguments read from standard input. Blank lines on the standard input are ignored.
• xbiff – graphical mail delivery notification utility
• xcalc – simple calculator program
• xclipboard – name says it all
• Xconfigurator – Red Hat utility for configuring settings for X
• xdm – used to start an X login session. This can be used to start a login session on a remote system.
See the man pages for X, xdm, and Xserver. As usual, the man pages are pretty obscure. The best single source seems to be the Xserver man pages. After X is configured, X needs to be started at bootup with the command (in /etc/rc.d/init.d/xterm):
o X -quiet -query remotemachineaddress
If the address of a nameserver is not configured, then the numeric address of the remote machine rather than its name should be entered. If the machines are connected through ethernet cards and the net, then obviously basic networking has to be set up. Gnome and KDE come with their own versions of X display/login managers, called respectively gdm and kdm.
• xdvi – view a dvi file compiled under LATEX
• xedit – a simple text editor for X
• xf86config – graphical configuration tool for X
• XF86Setup – graphical configuration tool for X
• xfd – display an available font in X. Creates a grid in an x-term with one character per rectangle.
• xfig – utility for interactive generation of figures
• xfm – graphical file manager for X
• xhost – tell X server that remote computer has access to your machine and that you will use the remote computer. This can be used to set up remote X sessions. To set up a remote X session on the UQAM Nobel machine, run the following command on the local machine (one doesn’t have to be root to do this)
o xhost +nobel.si.uqam.ca
Then, log onto the remote machine using rlogin (see above) or telnet. Once logged in, use the following command to get the remote X server to open an X terminal on the local machine:
o setenv DISPLAY localhostname:0 ; xterm &
This is valid for csh, which is the default login shell on Nobel. For ksh, (and I think bash) replace with
o DISPLAY=localhostname:0
o export DISPLAY ; xterm
Other X-based programs such as Netscape or Gauss (graphical version) can also be run on a remote machine with display on the local machine with little trouble. The local X server is the program that has all of the information concerning the properties of the graphics card and terminal, so it must be necessary to have X running on the local machine. The following should also work. After using xhost to give permission to the remote machine to display on the local machine, use
o netscape -display localhostname:0.0
Question: can one start the X session on the local machine and then run a remote copy of a window manager?
• xinit – start X Window. The command startx is a front end to xinit in Linux, including Slackware.
• xload – displays a graphic of the system load
• xlpq – graphical interface to print manager. This is included on one of the XFCE menus, but does not seem to be a part of the base Red Hat distribution.
• xlsfonts – list fonts available under the X Window system.
• xman – browsable command reference. Displays manual pages under X.
• xmh – graphical front end under X to the nmh mail handling system. This program is part of the XFree86 package in Red Hat.
• xmodmap – utility for modifying keymaps and pointer button mappings in X. Can be used to install a French Canadian keyboard. Download the Xmodmap.cf file from www.linux-quebec.org, and insert the command
o xmodmap /etc/X11/Xmodmap.cf &
into the .xession (with xdm) or the .xinitrc (with startx) file.
• xosview – displays bar graphs of system load, load average, memory usage, and swap usage
• xpaint – simple paint program for X
• xpdf – GPL’d utility for previewing dvi files. Doesn’t seem to work too well on texts with a lot of math.
• xplaycd – X Window audio cd player utility
• xsetroot – utility to configure root window of an X terminal
• xsysinfo – graphical display of load and memory usage
• xterm – start an X Window terminal session
• xterm-color – color version of xterm
• xv – utility for viewing and manipulating many types of image files. This is a shareware program.
• xvidtune – utility for fine tuning of monitor settings under X
• yacc – parser generator
• ytalk – multi-user program similar to talk
• zcat – read one or more files that have been compressed with gzip or compress and write to standard output
• zcmp – read compressed files and pass them to cmp
• zdiff – read compressed files and pass them to diff
• zgrep – read compressed files and pass them to grep
• Zharf – AfterStep button panel module
• zip – zip utility compatible with DOS PKzip
• zless – view zipped files
• zmore – print contents of compressed files one screen at a time
• znew – uncompress Z files and recompress in .gz format