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Linux Commands and references( GNU / linux kernel 2.4.18-3,
2.4.18-14 and 2.4.20-6 )
Linux is a registered trademark of Linus Torvalds
GO TO THE REVISED VERSION OF THIS PAGE WITH LINKS TO COMMANDS AND REFERENCES ON ONE PAGE
These are just a few of the most common GNU / Linux commands
athat you may find yourself looking for.
The index below is a work in progress. If you can't find the command and you arrived here from a search engine, try the search function in your browser.The commands with their most common usage are in brackets like this: [ command object_of_command ]. Of course after you type the command and the object of the command you must press enter to execute it on the object. Commands are case sensitive.
If you are new to Linux , you might want to read through an introduction to command line operations before you try these. You will need to be root to use some of these commands ; also be sure to check your path. If there is no path to the command then it will give you a " command not found " error. Check the command to be sure you have typed it correctly.If you get an error message when you type the command it may mean you need to be root to execute it. Be extremely careful as root , you can make your system unusable. This is very important to understand. If you are using a dual boot system you may not be able to access either system if you make a mistake as root and your system is not bootable. Before you type any command as root be absolutely certain of what you are doing.
Copyright (c) 2002 David Tarsi. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with the Invariant Sections being no invariant sections, with the Front-Cover Texts being no Front-Cover Texts, and with the Back-Cover Texts being no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".
GNU Free Documentation License
Questions or comments about this page content? contact
page last modified 2004-07-08 Perpetual PC's Home Page
The index below is a work in progress. If you can't find the command and you arrived here from a search engine, try the search function in your browser.The commands with their most common usage are in brackets like this: [ command object_of_command ]. Of course after you type the command and the object of the command you must press enter to execute it on the object. Commands are case sensitive.
Don't type the brackets, just what is inside of them.
Some of the commands include
parts that are not the actual command but must be typed before you press enter. The command
typed by itself often will not do anything but display a list of options. This is not always
true. For example the command [ df ] will show disk space used and disk space free.
On most systems more information about a command can be found by typing
[ man command ] ; man being the word man and command being the particular command you are
researching.If you are new to Linux , you might want to read through an introduction to command line operations before you try these. You will need to be root to use some of these commands ; also be sure to check your path. If there is no path to the command then it will give you a " command not found " error. Check the command to be sure you have typed it correctly.If you get an error message when you type the command it may mean you need to be root to execute it. Be extremely careful as root , you can make your system unusable. This is very important to understand. If you are using a dual boot system you may not be able to access either system if you make a mistake as root and your system is not bootable. Before you type any command as root be absolutely certain of what you are doing.
Copyright (c) 2002 David Tarsi. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with the Invariant Sections being no invariant sections, with the Front-Cover Texts being no Front-Cover Texts, and with the Back-Cover Texts being no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".
GNU Free Documentation License
Questions or comments about this page content? contact
page last modified 2004-07-08 Perpetual PC's Home Page
Contents
A | B | Bt | C | Ca | Cat | Co | Cp | D | Di | Dis | E | F | Fi | Fr | G | H | I | If | Ip | L | Li | M | N | O | P | Pr | Q | R | Sa | Se | Sl | So | T | Ti | U | V, W | X, Y, Z
Perpetual PC's home page
Perpetual PC's link page
add new disk drive:
First: [ fdisk /dev/hda ] gets you to fidisk on first harddrive [ fdisk /dev/hdb ] is second hdd. You will need to put some partitions on the disk first with fdisk. You will need to know which disk you are adding( hda or hdb or hdc this is for ide drives (/dev/hd[a-h] for IDE disks, /dev/sd[a-p] for SCSI disks, /dev/ed[a-d] for ESDI disks, /dev/xd[ab] for XT disks; A device name refers to the entire disk.)) Then: [ mkfs /dev/hda1 ] formats the partition. Add your directory [ mkdir /new ] Next: edit /etc/fstab ; add the line
/dev/hdb1 /new ext2 defaults 1 1
[ mount -a ] as root mounts all partitions in fstab.
First: [ fdisk /dev/hda ] gets you to fidisk on first harddrive [ fdisk /dev/hdb ] is second hdd. You will need to put some partitions on the disk first with fdisk. You will need to know which disk you are adding( hda or hdb or hdc this is for ide drives (/dev/hd[a-h] for IDE disks, /dev/sd[a-p] for SCSI disks, /dev/ed[a-d] for ESDI disks, /dev/xd[ab] for XT disks; A device name refers to the entire disk.)) Then: [ mkfs /dev/hda1 ] formats the partition. Add your directory [ mkdir /new ] Next: edit /etc/fstab ; add the line
/dev/hdb1 /new ext2 defaults 1 1
[ mount -a ] as root mounts all partitions in fstab.
add new user
First log in as root.
Then: [ useradd user1 ] adds new user named user1
Then; [ passwd user1 ] gets you to a prompt asking for the new password for user1. Type in the password you want and hit enter, then the system will ask you to confirm the password, and you will be scolded if you enter a lame password; but the system will let you go ahead and enter a weak password, so be careful. This works on Red Hat 7.3. However know that it is just the systems defaults that are given to the new user. The new user gets a home directory and can run programs; you can do this on the command line. Requires root privilages to add a new user.
First log in as root.
Then: [ useradd user1 ] adds new user named user1
Then; [ passwd user1 ] gets you to a prompt asking for the new password for user1. Type in the password you want and hit enter, then the system will ask you to confirm the password, and you will be scolded if you enter a lame password; but the system will let you go ahead and enter a weak password, so be careful. This works on Red Hat 7.3. However know that it is just the systems defaults that are given to the new user. The new user gets a home directory and can run programs; you can do this on the command line. Requires root privilages to add a new user.
apache start
usually located in /etc/rc.d/inet.d/ as httpd
on RedHat: [ service httpd start ] [ service httpd stop ] [ service httpd reload ]
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usually located in /etc/rc.d/inet.d/ as httpd
on RedHat: [ service httpd start ] [ service httpd stop ] [ service httpd reload ]
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balsa setup
The smtp server must be set to localhost:25 because balsa defaults to a different port.
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The smtp server must be set to localhost:25 because balsa defaults to a different port.
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calculator
two commands are available for command line calcualtors:
[ dc ] this is the most simplistic
[ bc ] this is less primitive
type [ quit ] to exit either one of the above calculators
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two commands are available for command line calcualtors:
[ dc ] this is the most simplistic
[ bc ] this is less primitive
type [ quit ] to exit either one of the above calculators
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change group of all in directory
[ chgrp -R groupname /directoryname ]
[ chgrp -R groupname /directoryname ]
change history size
[ HISTSIZE=10 ] this makes the history size 10 commands
[ HISTSIZE=10 ] this makes the history size 10 commands
change ownership of dir and all files
[ chown -R username /directoryname ]
[ chown -R username /directoryname ]
change time / date stamp of file called filename
[ touch -t ccyymmddhhmm.ss filename ]
[ touch -t ccyymmddhhmm.ss filename ]
colors, text:
To change the file type colors for the ls command
first you may want to type [ env ]
this will display your environment vars. In this you should see a LS_COLORS statement followed by a large number of statements like fi=00:di=00;34:ln=00;36:pi=40;33 and so on. this will be a large list. This is where the colors are set when you type the command ls.
This list tells you what kind of files get what color. These numbers ( the 34 or the 36 or the 33 ) are the iso 6429 color codes .
What you will need to do is change these values to suit your preference. You can change them temporarily by using a command in an xterm window something like : [ export LS_COLORS="*.html=32:di=1;36" ] this will change the color of all .html file listings in your current xterm window to a dark green and the directory listings to cyan. when you exit the xterm window everything goes back to default. Or you can change them permenantly by ( as root ) changing the listings in the /etc/DIR_COLORS.xterm file. Be careful when you do this. As root you can damage your system beyond recovery with one tiny mistake.
The above worked on RedHat 8.0 (2.4.18-14). It may not be exactly the same on other systems.
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command line login (after installing Debian GNU Linux)
If you have installed Debian GNU Linux and can't get to the command line login, you may need to turn off xdm. Also if you want to change which window manager runs; you will need to change the symbolic links in the /etc/alternatives file. The information here explains how to make the changes needed to get a command line login
If you have installed Debian GNU Linux and can't get to the command line login, you may need to turn off xdm. Also if you want to change which window manager runs; you will need to change the symbolic links in the /etc/alternatives file. The information here explains how to make the changes needed to get a command line login
Command to make file foo owned by user
[ chown user /home/foo ] also makes the dir foo ( if foo is a directory and not a file ) owned by user
[ chown user /home/foo ] also makes the dir foo ( if foo is a directory and not a file ) owned by user
command not found:
There are many requests appearing in our weblog that relate to this. If you are getting a message like this there is usually a simple solution to your problem. For example let's say you want to run the command [ ip ], and you get something like below:
bash: ip: command not found
Then do this: [ whereis ip ], and then you should see this:
ip: /sbin/ip /usr/share/man/man7/ip.7.gz /usr/share/man/man8/ip.8.gz
Ok, now you know where the binary executable is. ( Don't confuse this with the .exe suffix or the .com suffix they don't apply here ).
Now type this: [ /sbin/ip ], and you should get something like this:
This applies to any command you type that gives you the command not found message. What it is telling you is that there is no path from your directory to the executable filename you have typed.
There are many requests appearing in our weblog that relate to this. If you are getting a message like this there is usually a simple solution to your problem. For example let's say you want to run the command [ ip ], and you get something like below:
bash: ip: command not found
Then do this: [ whereis ip ], and then you should see this:
ip: /sbin/ip /usr/share/man/man7/ip.7.gz /usr/share/man/man8/ip.8.gz
Ok, now you know where the binary executable is. ( Don't confuse this with the .exe suffix or the .com suffix they don't apply here ).
Now type this: [ /sbin/ip ], and you should get something like this:
Usage: ip [ OPTIONS ] OBJECT { COMMAND | help }
where OBJECT := { link | addr | route | rule | neigh | tunnel |
maddr | mroute | monitor }
OPTIONS := { -V[ersion] | -s[tatistics] | -r[esolve] |
-f[amily] { inet | inet6 | ipx | dnet | link } | -o[neline] }This applies to any command you type that gives you the command not found message. What it is telling you is that there is no path from your directory to the executable filename you have typed.
compare 2 sorted files line by line
[ comm file1 file2 ]
[ comm file1 file2 ]
compare files
[ diff file1 file2 ]
[ diff file1 file2 ]
cooked
in other words ; formatted output on the command line
[ stty cooked ]
[ stty cooked ]
copy all files in dir to anotherdir
[ cp -r dir/* anotherdir ]
copy all directories and subdirectories and files in the foo directory to the foos_backup directory in which you create the directory backup_one which will contain all that is in the foo directory:
[ cp -r foo foos_backup/backup_one ]
to copy filenames with spaces use quotes around them like this: "file name with spaces.txt"
[ cp -r dir/* anotherdir ]
copy all directories and subdirectories and files in the foo directory to the foos_backup directory in which you create the directory backup_one which will contain all that is in the foo directory:
[ cp -r foo foos_backup/backup_one ]
to copy filenames with spaces use quotes around them like this: "file name with spaces.txt"
convert files for printing
[ pr ]
[ pr ]
count files in a directory / or directories :
[ tree ]
This command will also list all the files in the directory you are in when you type it. So if you are in the top directory of your home directory you will get a count and a list of all the files and sub-directories in your home directory.If you type this command in the / directory of the system you will get thousands and thousands of files screaming by as you watch. When it finishes there will be a file and directory count listed. You must have the "tree" program installed. This command, like most others, has many options. some of them are:
[ tree -a ], list all files including hidden
[ tree -d ], list only directories
[ tree -s ], also list size
[ tree -C ], list in color
[ tree -A ], nice formatting
[ tree -s > my_files ] send a list of all files with their sizes to a file called my_files. If you have several thousand files, this method allows you to conveniently look at them.
cpu usage ( display top CPU processes )
[ top ]
to display hardware info of the cpu ( Display Processor Type )
[ cat /proc/cpuinfo ]
[ top ]
to display hardware info of the cpu ( Display Processor Type )
[ cat /proc/cpuinfo ]
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create an empty file called filename
[ touch filename ]
[ touch filename ]
Date, set date ( as root )
[ date -s 'Sat May 24 14:43:00 PDT 2003' ]
this is only one way to set the date, there are many other options you can see by typing: [ man date ]
[ date -s 'Sat May 24 14:43:00 PDT 2003' ]
this is only one way to set the date, there are many other options you can see by typing: [ man date ]
disk drive access
In GNU/Linux we "mount" a drive to access the files on it. If you are new to GNU/Linux, this may seem strange and awkward, but after you understand how this process works you will find that it is a very flexible method of accessing files.
First floppy drive
[ mount /mnt/floppy ]
mount the cdrom drive
[ mount /mnt/cdrom ]
After you mount the drive you must "cd" to the directory in which it is mounted; so do this for the floppy
[ cd /mnt/floppy ]
or this for the cdrom
[ cd /mnt/cdrom ].
( the "cd" in the command stands for "change directory" it is not the same thing as the "cd" in "cdrom".)
These commands will be different in other versions of this operating system. For example, you may need to be root to mount a drive on some systems. The key is to remember that you access file systems by "mounting" them with the mount command. This can also include partitions.
When you want to change the floppy use the umount command (unmount); first do this:
[ cd ] ( this gets you out of the /mnt/floppy directory )
then do this
[ umount /mnt/floppy ]
Use the same procedure for the cdrom drive. See also usb floppy
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In GNU/Linux we "mount" a drive to access the files on it. If you are new to GNU/Linux, this may seem strange and awkward, but after you understand how this process works you will find that it is a very flexible method of accessing files.
First floppy drive
[ mount /mnt/floppy ]
mount the cdrom drive
[ mount /mnt/cdrom ]
After you mount the drive you must "cd" to the directory in which it is mounted; so do this for the floppy
[ cd /mnt/floppy ]
or this for the cdrom
[ cd /mnt/cdrom ].
( the "cd" in the command stands for "change directory" it is not the same thing as the "cd" in "cdrom".)
These commands will be different in other versions of this operating system. For example, you may need to be root to mount a drive on some systems. The key is to remember that you access file systems by "mounting" them with the mount command. This can also include partitions.
When you want to change the floppy use the umount command (unmount); first do this:
[ cd ] ( this gets you out of the /mnt/floppy directory )
then do this
[ umount /mnt/floppy ]
Use the same procedure for the cdrom drive. See also usb floppy
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display current directory files and permissions
[ ls -ld ]
[ ls -ld ]
display disk usage on mounted partitions(displays mounted partition names,
sizes and usage)
[ df ]
see also: file space usage estimate
[ df ]
see also: file space usage estimate
display environment variables
[ env ]
[ env ]
display last line first of file called filename
[ tac filename ]
display ( concatenate ) file called filename
[ cat filename ]
display information about system version
[ cat /proc/version ]
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[ tac filename ]
display ( concatenate ) file called filename
[ cat filename ]
display information about system version
[ cat /proc/version ]
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documentation , access to( type the command listed below then the
specific subject or command for which you want info.
You must have documentation installed on your system
for this to work.)
[ man ] example: [ man vim ] displays the manual for the vim (vi improved) editor
[ man ] example: [ man vim ] displays the manual for the vim (vi improved) editor
edit a file named foo
[ pico foo ]
editing can be accomplished by a number of editors. To get pico you must install pine. Pine is a mail program; in the RedHat distro it is an rpm. Install Pine and you will have pico. If you are using Debian, nano is the editor similar to pico. In my opinion, vim and gvim are also very good editors. So to edit the file named foo you would do [ vim foo ]
or [ gvim foo ]
gvim works in xwindows and gives you a nice graphical interface. Vim and gvim have syntax highlighting which is configurable ( see vim colors ). Vim and Pico will work at the command line. This is by far only the tip of the iceberg as far as editors go.
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[ pico foo ]
editing can be accomplished by a number of editors. To get pico you must install pine. Pine is a mail program; in the RedHat distro it is an rpm. Install Pine and you will have pico. If you are using Debian, nano is the editor similar to pico. In my opinion, vim and gvim are also very good editors. So to edit the file named foo you would do [ vim foo ]
or [ gvim foo ]
gvim works in xwindows and gives you a nice graphical interface. Vim and gvim have syntax highlighting which is configurable ( see vim colors ). Vim and Pico will work at the command line. This is by far only the tip of the iceberg as far as editors go.
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extract : to untar (extract) a file named filename.tar type:
[ tar xf filename.tar ]
to list the files in a tar archive named filename.tar type:
[ tar tf filename.tar ]
the dash before the tf was not needed on my system which is RedHat with kernel version 2.4.18-14.
[ tar xf filename.tar ]
to list the files in a tar archive named filename.tar type:
[ tar tf filename.tar ]
the dash before the tf was not needed on my system which is RedHat with kernel version 2.4.18-14.
[ fdisk ]
type this as root for linux fdisk program
follow help carefully you can make your hard disk unreadable if you are not careful
type this as root for linux fdisk program
follow help carefully you can make your hard disk unreadable if you are not careful
file space usage estimate
show amount of space files and directories take up on disk [ du -a -h ]
show amount of space directories take on disk [ du -h ]
[ ls -la -h ] will show files and their sizes in kilobytes.
[ ls -al -b ] will show files and their sizes in bytes.
There are many options to these commands. those listed above together have over 50 options. It is strongly recommended becoming familiar with the manual. If you do not have the man pages on your system, it would probably be a good idea to install them. For example, typing [ man du ] will show you the options for that command.
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show amount of space files and directories take up on disk [ du -a -h ]
show amount of space directories take on disk [ du -h ]
[ ls -la -h ] will show files and their sizes in kilobytes.
[ ls -al -b ] will show files and their sizes in bytes.
There are many options to these commands. those listed above together have over 50 options. It is strongly recommended becoming familiar with the manual. If you do not have the man pages on your system, it would probably be a good idea to install them. For example, typing [ man du ] will show you the options for that command.
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Format ( to format disks use the mkfs command )
must be root for these commands
format a floppy disk ( format a floppy disk so it can be used with ms stuff ) do not mount the disk first in any case; be sure it is unmounted
[ mkfs.msdos /dev/fd0 ] this works on kernel version 2.4.18-14
format a floppy disk with default linux file system
[ mkfs /dev/fd0 ]
( this also works on harddisks like /dev/hda or /dev/hdb )
must be root for these commands
format a floppy disk ( format a floppy disk so it can be used with ms stuff ) do not mount the disk first in any case; be sure it is unmounted
[ mkfs.msdos /dev/fd0 ] this works on kernel version 2.4.18-14
format a floppy disk with default linux file system
[ mkfs /dev/fd0 ]
( this also works on harddisks like /dev/hda or /dev/hdb )
grep (see search a file)
[ grep ]
[ grep ]
hard drive hardware information:
[ hdparm ]
This command is EXTREMELY DANGEROUS. Do not use it unless you know exactly what you are doing. Please read the man page carefully before you use it. One mistake and you will likely loose everything. It must be run as root. To get the info as it was read from the drive at boot time, which usually includes the serial number and model number of the drive type:
[ hdparm -I /dev/hda ] that is an upper case i after hdparm second ide drive would be /dev/hdb
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[ hdparm ]
This command is EXTREMELY DANGEROUS. Do not use it unless you know exactly what you are doing. Please read the man page carefully before you use it. One mistake and you will likely loose everything. It must be run as root. To get the info as it was read from the drive at boot time, which usually includes the serial number and model number of the drive type:
[ hdparm -I /dev/hda ] that is an upper case i after hdparm second ide drive would be /dev/hdb
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hardware information
A lot of the info about the hardware is in the /proc file. If you type [ cat /proc/* ] you will get several thousand lines of info about hardware and memory locations. Perhaps a better way is to look in the proc directory and examine the individual files and directories; most of which have names reflecting their content;
or type [ cat /proc/* > hardware_file ] to send the ouput to hardware_file.
A lot of the info about the hardware is in the /proc file. If you type [ cat /proc/* ] you will get several thousand lines of info about hardware and memory locations. Perhaps a better way is to look in the proc directory and examine the individual files and directories; most of which have names reflecting their content;
or type [ cat /proc/* > hardware_file ] to send the ouput to hardware_file.
history size
To change the size of the command history
[ HISTSIZE=10 ] this makes the history size 10 commands
to change the size just change the number from 10 to your preference.
To change the size of the command history
[ HISTSIZE=10 ] this makes the history size 10 commands
to change the size just change the number from 10 to your preference.
ifconfig
You will probably need to type [ /sbin/ifconfig ]
typed on my system gives the following information: ( the x's will be different on your system )
You will probably need to type [ /sbin/ifconfig ]
typed on my system gives the following information: ( the x's will be different on your system )
eth0 Link encap:Ethernet HWaddr xx:xx:xx:xx:xx:xx
inet addr:xxx.xxx.xxx.xxx Bcast:xxx.xxx.xxx.xxx Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:155836 errors:0 dropped:0 overruns:0 frame:0
TX packets:135659 errors:3 dropped:0 overruns:0 carrier:3
collisions:6561 txqueuelen:100
RX bytes:22008941 (20.9 Mb) TX bytes:103466699 (98.6 Mb)
Interrupt:9 Base address:0x9f00
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:469 errors:0 dropped:0 overruns:0 frame:0
TX packets:469 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:40739 (39.7 Kb) TX bytes:40739 (39.7 Kb)
ppp0 Link encap:Point-to-Point Protocol
inet addr:xxx.xxx.xxx.xxx P-t-P:xxx.xxx.xxx.xxx Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1
RX packets:2202 errors:2 dropped:0 overruns:0 frame:0
TX packets:1749 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:1765648 (1.6 Mb) TX bytes:106296 (103.8 Kb)
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invoke previous command
[ !! ]
[ !! ]
irq information
[ cat /proc/interrupts ]
This will display irq info for your machine. There is much information about your machine in the /proc directory; it would be worth checking it out.
[ cat /proc/interrupts ]
This will display irq info for your machine. There is much information about your machine in the /proc directory; it would be worth checking it out.
linux bootdisk for system(this is a boot disk,not an installation
bootdisk)
[ mkbootdisk --device /dev/fd0 2.4.18-3 ]
[ uname -r ] gets you the version number which is 2.4.18-3 in the above example
[ mkbootdisk --device /dev/fd0 2.4.18-3 ]
[ uname -r ] gets you the version number which is 2.4.18-3 in the above example
linux bootdisk for installation of RedHat 7.3
(this allows starting the installation program
from a floppy disk. You must mount the installation CD disk
and be in the images directory first. These commands require root
privilages. fd0 is the name of the first floppy drive.Do not mount
the floppy disk.)
[ dd if=boot.img of=/dev/fd0 bs=1440k ]
[ dd if=boot.img of=/dev/fd0 bs=1440k ]
list all in current dir and alll below
[ ls -R ]
[ ls -R ]
list all partitions on all drives
( as root ) [ sfdisk -l ]
see also file space usage
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( as root ) [ sfdisk -l ]
see also file space usage
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list in color
[ ls --color ]
[ ls --color ]
list files, file sizes and hidden files ( all files in current directory )
[ ls -la ]
[ ls -la ]
locate a file
there are a number of ways to locate a file. To find a command's binary and other info type [ whereis ] followed by the name of the command you are looking for and you will get a detailed listing.
you can also type [ locate ] followed by the file you are looking for and if it has been added to the database you will get its location.
also you can type [ find ] followed by the path and expression or file/files you are looking for. For example if you want to know how many html files there are in directory stuff do this (in the stuff directory): [ find *.html ] you will get a list of all the .html files in the stuff directory.
there are a number of ways to locate a file. To find a command's binary and other info type [ whereis ] followed by the name of the command you are looking for and you will get a detailed listing.
you can also type [ locate ] followed by the file you are looking for and if it has been added to the database you will get its location.
also you can type [ find ] followed by the path and expression or file/files you are looking for. For example if you want to know how many html files there are in directory stuff do this (in the stuff directory): [ find *.html ] you will get a list of all the .html files in the stuff directory.
lock the screen from the command line
[ xscreensaver-command -lock ]
There must be a screensaver running for this to work.
[ xscreensaver-command -lock ]
There must be a screensaver running for this to work.
man page; print a manual page to a text file
Ever want to send a manual page to a text file?
This command will do it: [ man foo | col -b > foo.mantxt ]
It puts the manual page for foo in the file foo.mantxt
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Ever want to send a manual page to a text file?
This command will do it: [ man foo | col -b > foo.mantxt ]
It puts the manual page for foo in the file foo.mantxt
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Network configuration information.
This command will give you detailed information on your networking configuration
[ ifconfig ]
(on my system I have to type [ /sbin/ifconfig ] , yours may be different depending on your path setting)
The command
[ man ifconfig ]
will get you a detailed explanation of how this command works. It is possible to change the ip address of a given interface with this command.
For example ( as root ) [ ifconfig eth0 192.168.0.2 ] will set the ip address of your first nic to 192.168.0.2.
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This command will give you detailed information on your networking configuration
[ ifconfig ]
(on my system I have to type [ /sbin/ifconfig ] , yours may be different depending on your path setting)
The command
[ man ifconfig ]
will get you a detailed explanation of how this command works. It is possible to change the ip address of a given interface with this command.
For example ( as root ) [ ifconfig eth0 192.168.0.2 ] will set the ip address of your first nic to 192.168.0.2.
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not so primitive calculator
[ bc ]
[ bc ]
nice: run a command nicely with an adjusted priority
Range is -20(high) to 19(low).
[ nice -n 15 foo ] this runs foo with priorty 15
non root users can only lower priority ( higher number ).
Range is -20(high) to 19(low).
[ nice -n 15 foo ] this runs foo with priorty 15
non root users can only lower priority ( higher number ).
path ( display the path ) this will display more than just the path, but
the path will be in there. It is important to know your path because sometimes
you will get a "command not found" error that is caused because there is no path
to the command you have typed.
[ env ]
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[ env ]
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primitive calculator
[ dc ]
[ dc ]
print a manual entry for subject.This is a very important command
as it gives you access to the manual for Linux. There is an enormous
amount of information avaliable.
[ man subject | lpr ]
[ man subject | lpr ]
printer jobs and status
[ lpstat -t ]
[ lpstat -t ]
printer jobs status
[ lpstat ]
[ lpstat ]
print terminal line settings
[ stty -a ]
[ stty -a ]
print working directory
[ pwd ]
[ pwd ]
process on port 22 system 5
[ ps -ft 22 ]
[ ps -ft 22 ]
remove duplicate lines from file
[ uniq ]
[ uniq ]
resize windows if size is wrong
[ reset ]
[ reset ]
Resolution:(xrandr)
To check for xrandr on your system type
[ xdpyinfo ]
(If you see RANDR listed under number of extensions then it should work.)
To change the resolution (monitor display) from the command line ( using a terminal window ) do this: ( when x is running )
[ xrandr ]
this command will bring up information like this:
This will show the resolutions possible on your monitor. The star indicates what is currently being used. To change resolution use a command like this:
[ xrandr -s 1024x760 ]
This will immediately change the resolution. ( it takes about 1.5 seconds on my system which uses a "Super View 1280" monitor which is actually an Hitachi cm500 as far as specifications go -- I am using RedHat with kernel 2.4.20-6 and Xfree86 version 4.3.0 )
Also typing
[ xrandr -s ]
will give this information:
This assumes you monitor is set up with vertical and horizontal specifications that it can handle. Be aware that you can destroy your monitor with the wrong settings.
To check for xrandr on your system type
[ xdpyinfo ]
(If you see RANDR listed under number of extensions then it should work.)
To change the resolution (monitor display) from the command line ( using a terminal window ) do this: ( when x is running )
[ xrandr ]
this command will bring up information like this:
SZ: Pixels Physical Refresh 0 1024 x 768 ( 271mm x 201mm ) 75 70 60 1 800 x 600 ( 271mm x 201mm ) 85 75 72 60 56 2 640 x 480 ( 271mm x 201mm ) 85 75 72 60 *3 832 x 624 ( 271mm x 201mm ) *74 4 720 x 400 ( 271mm x 201mm ) 85 5 640 x 400 ( 271mm x 201mm ) 85 6 640 x 350 ( 271mm x 201mm ) 85 Current rotation - normal Current reflection - none Rotations possible - normal Reflections possible - none
This will show the resolutions possible on your monitor. The star indicates what is currently being used. To change resolution use a command like this:
[ xrandr -s 1024x760 ]
This will immediately change the resolution. ( it takes about 1.5 seconds on my system which uses a "Super View 1280" monitor which is actually an Hitachi cm500 as far as specifications go -- I am using RedHat with kernel 2.4.20-6 and Xfree86 version 4.3.0 )
Also typing
[ xrandr -s ]
will give this information:
usage: xrandr [options]
where options are:
-display <display> or -d <display>
-help
-o <normal,inverted,left,right,0,1,2,3>
or --orientation <normal,inverted,left,right,0,1,2,3>
-q or --query
-s <size>/<width>x<height> or --size <size>/<width>x<height>
-r <rate> or --rate <rate>
-v or --version
-x (reflect in x)
-y (reflect in y)
--screen <screen>
--verbose
This assumes you monitor is set up with vertical and horizontal specifications that it can handle. Be aware that you can destroy your monitor with the wrong settings.
resource usage
[ top ]
this command shows a large table with ( in addition to other data ) cpu and memory percentage use
[ top ]
this command shows a large table with ( in addition to other data ) cpu and memory percentage use
become root user
[ su - ]
this command lets you become root or "Super User" after you type it and hit enter you will be prompted for the root password, enter the correct password and you are root. Be careful you now have the power to destroy your system.
to get back to your own account do: [ exit ]
[ su - ]
this command lets you become root or "Super User" after you type it and hit enter you will be prompted for the root password, enter the correct password and you are root. Be careful you now have the power to destroy your system.
to get back to your own account do: [ exit ]
rpm install
[ rpm -ivh ] gives messages
[ rpm -ivh ] gives messages
rpm list files in a package
[ rpm -q -l ]
[ rpm -q -l ]
rpm query all
[ rpm -q -a ]
[ rpm -q -a ]
rpm query and give info
[ rpm -q -i ]
[ rpm -q -i ]
rpm which package owns a file
[ rpm -q -f ]
[ rpm -q -f ]
run levels
[ 0 is halt ] [ 1 is single user w/o nfs ] [ 2 is multi user w/o nfs ]
[ 3 is multi user w nfs ]
[ 4 is unused ] [ 5 is X windows ] [ 6 is reboot ]
[ 0 is halt ] [ 1 is single user w/o nfs ] [ 2 is multi user w/o nfs ]
[ 3 is multi user w nfs ]
[ 4 is unused ] [ 5 is X windows ] [ 6 is reboot ]
samba
Encrypted passwords. Create /etc/smbpasswd. Make sure < encrypt passwd > and < samba password file > are uncommented in smb.conf
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Encrypted passwords. Create /etc/smbpasswd. Make sure < encrypt passwd > and < samba password file > are uncommented in smb.conf
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samba
to add user [ smbpasswd -a userid ]
to add user [ smbpasswd -a userid ]
samba
[ mount -t smbfs -o username=jdoe,password=jdoepasswrd //ada/jdoe /mnt/test ]
the above command will allow you ( as root ) to mount an smb share named jdoe on the linux samba server named ada from a machine running linux. As root you will need to know jdoe's password and user name and you will want to make the directory /mnt/test before you attempt to mount the share on it. You must have samba running and the shares configured or this won't work. This was done on a network without dhcp. For this example the server has kernel 2.4.2-2 ( RedHat 7.1 ) and the other machine has 2.4.18.14 both GNU/Linux.
[ mount -t smbfs -o username=jdoe,password=jdoepasswrd //ada/jdoe /mnt/test ]
the above command will allow you ( as root ) to mount an smb share named jdoe on the linux samba server named ada from a machine running linux. As root you will need to know jdoe's password and user name and you will want to make the directory /mnt/test before you attempt to mount the share on it. You must have samba running and the shares configured or this won't work. This was done on a network without dhcp. For this example the server has kernel 2.4.2-2 ( RedHat 7.1 ) and the other machine has 2.4.18.14 both GNU/Linux.
samba
Mount win98 or win95 shared resource from linux [ smbmount //ada/ada_c /mnt/ada_c ] where ada is the name of the windows computer and ada_c is the name of the windows drive share. /mnt/ada_c is the name of the directory you create on your linux machine. The resource must be shared at the winbox and the winbox must be configured for networking. [ smbclient \\\\ada\\ada_c ] gets you to a password prompt for the share. Then you will get smb: \ if you typed the correct password.
Mount win98 or win95 shared resource from linux [ smbmount //ada/ada_c /mnt/ada_c ] where ada is the name of the windows computer and ada_c is the name of the windows drive share. /mnt/ada_c is the name of the directory you create on your linux machine. The resource must be shared at the winbox and the winbox must be configured for networking. [ smbclient \\\\ada\\ada_c ] gets you to a password prompt for the share. Then you will get smb: \ if you typed the correct password.
samba
On win2k be sure your share includes the name of your workgroup. Keep it the same as in the samba flle. On the win2k share put workgroup < mygrp > as one of the authorized users in your smb.conf file list the workgroup as < mygrp > and put the ip of your win2k host in your /etc/hosts file.
On win2k be sure your share includes the name of your workgroup. Keep it the same as in the samba flle. On the win2k share put workgroup < mygrp > as one of the authorized users in your smb.conf file list the workgroup as < mygrp > and put the ip of your win2k host in your /etc/hosts file.
samba
[ smbclient -L ada ] gets you to password prompt then a listing of all shares on ada
[ smbclient -L ada ] gets you to password prompt then a listing of all shares on ada
samba
To make a share work. You must create the directories in your system exactly as they are described in the smb.conf file.then set ownership of the directory with the chown command to make ait visible to owner only.at the command prompt you could type [ chown someone /usr/ someone/shared ] this makes the directory shared only visible to someone.
To make a share work. You must create the directories in your system exactly as they are described in the smb.conf file.then set ownership of the directory with the chown command to make ait visible to owner only.at the command prompt you could type [ chown someone /usr/ someone/shared ] this makes the directory shared only visible to someone.
search a file (for everything except something)
[ grep -v 64.38 file.name ]
searches the file "file.name" for everything except the expression 64.38
[ grep -v 64.38 file.name > new_file ]
searches the file "file.name" for every thing except the expression 64.38 and sends the results to the file "new_file".
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[ grep -v 64.38 file.name ]
searches the file "file.name" for everything except the expression 64.38
[ grep -v 64.38 file.name > new_file ]
searches the file "file.name" for every thing except the expression 64.38 and sends the results to the file "new_file".
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search a file
[ grep 64.38 file.name ]
searches the file "file.name" for the expression 64.38
[ grep 64.38 file.name > new_file ]
searches the file "file.name" for the expression 64.38 and sends the results to the file "new_file".
[ grep 64.38 file.name ]
searches the file "file.name" for the expression 64.38
[ grep 64.38 file.name > new_file ]
searches the file "file.name" for the expression 64.38 and sends the results to the file "new_file".
search for a word in a file in a directory (for example your home directory) tree:
Lets say you are looking for the word foo
try this:
[ grep -r -w "\<foo\>" * > findfoo ]
this will search the directory tree recursively and send the output to the file findfoo. If your directory tree contains many files and directories this file will be huge, so be cautioned.
Once you have the file findfoo, do this:
[ grep foo findfoo ]
this will display the line and the file that the word foo is in.
Lets say you are looking for the word foo
try this:
[ grep -r -w "\<foo\>" * > findfoo ]
this will search the directory tree recursively and send the output to the file findfoo. If your directory tree contains many files and directories this file will be huge, so be cautioned.
Once you have the file findfoo, do this:
[ grep foo findfoo ]
this will display the line and the file that the word foo is in.
send the output of a command to a file
[ foo > stuff ]
this sends the output of the foo command to the file named stuff
[ foo > stuff ]
this sends the output of the foo command to the file named stuff
set gid
[ chmod g+s ]
[ chmod g+s ]
[ set serial ]
changes the irq of a serial port
changes the irq of a serial port
set uid
[ chmod u+s ]
[ chmod u+s ]
set uid and gid
[ chmod +s ]
[ chmod +s ]
set uid and gid and rwx for all in dir
[ chmod a=rwx,+s * ] not recomended very dangerous
[ chmod a=rwx,+s * ] not recomended very dangerous
set uid and unset gid
[ chmod u+s,g-s ]
[ chmod u+s,g-s ]
[ setup ]
typed at prompt in Red Hat linux 7.3 gets you to a configuration menu where you can setup firewall, mouse, keyboard, network, printer, system services, sound card, time zone, X configuration(colors, resolution, monitor, video card.
typed at prompt in Red Hat linux 7.3 gets you to a configuration menu where you can setup firewall, mouse, keyboard, network, printer, system services, sound card, time zone, X configuration(colors, resolution, monitor, video card.
slackware 8 bootdisk and rootdisk( both needed for installation)
From the command prompt in Linux, use the dd command for both bootdisk and rootdisk( 1.44m floppy ), do as follows from the bootdsks.144 directory for bare.i, and the rootdsks directory for color.gz ( located on the cdrom disk )( fd0 is the first floppy drive. Be sure which one you are using. )
[ dd if=bare.i of=/dev/fd0 obs=18k ] and [ dd if=color.gz of=/dev/fd0 obs=18k ]
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From the command prompt in Linux, use the dd command for both bootdisk and rootdisk( 1.44m floppy ), do as follows from the bootdsks.144 directory for bare.i, and the rootdsks directory for color.gz ( located on the cdrom disk )( fd0 is the first floppy drive. Be sure which one you are using. )
[ dd if=bare.i of=/dev/fd0 obs=18k ] and [ dd if=color.gz of=/dev/fd0 obs=18k ]
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slackware setup
go to series >a< and select one kernel to install use expert mode for this
go to series >a< and select one kernel to install use expert mode for this
sort a file
to sort a file named foo with numbers and letters at the beginning of lines, and display the result omitting duplicate entries try this:
[ sort -u foo ]
or send the output to a file named sorted_file1:
[ sort -u foo > sorted_file1 ]
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to sort a file named foo with numbers and letters at the beginning of lines, and display the result omitting duplicate entries try this:
[ sort -u foo ]
or send the output to a file named sorted_file1:
[ sort -u foo > sorted_file1 ]
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stop ppp0
[ ifconfig ppp0 down ]
[ ifconfig ppp0 down ]
stop ppp daemon
[ killall pppd ]
[ killall pppd ]
stop a command from running:
hold down the Ctrl and c keys simultaneously
hold down the Ctrl and c keys simultaneously
su (to become super user) (see also root)
In free BSD edit /etc/group and change the line wheel:*:0root to wheel:*:0root,youruserid do not add any spaces
In free BSD edit /etc/group and change the line wheel:*:0root to wheel:*:0root,youruserid do not add any spaces
swap
to activate a swap file on hdc1: [ mkswap /dev/hdc1 ]
If you have the manual installed, you might want to type in [ man swapon ] for more options.
to activate a swap file on hdc1: [ mkswap /dev/hdc1 ]
If you have the manual installed, you might want to type in [ man swapon ] for more options.
Time
, set time zone ( as root )( see also date and set date / time )
this command as shown sets the time zone to the Yukon in Canada.It works on Red Hat kernel version 2.4.18-14 and may work on others. You can find the various time zones listed in the directory /usr/share/zoneinfo. When you type this command as root, be careful and be sure you have the correct path for the zone you want; look carefully at the above listed diretory before you type the command.
[ timeconfig Canada/Yukon]
Just typing
[ timeconfig ]
as root opens up a dialog box that may be more convienent for some users. The binary /usr/sbin/zic is used to compile the timezone information.
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this command as shown sets the time zone to the Yukon in Canada.It works on Red Hat kernel version 2.4.18-14 and may work on others. You can find the various time zones listed in the directory /usr/share/zoneinfo. When you type this command as root, be careful and be sure you have the correct path for the zone you want; look carefully at the above listed diretory before you type the command.
[ timeconfig Canada/Yukon]
Just typing
[ timeconfig ]
as root opens up a dialog box that may be more convienent for some users. The binary /usr/sbin/zic is used to compile the timezone information.
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touch, create an empty file called filename
[ touch filename ]
[ touch filename ]
unset gid
[ chmod g-s ]
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unset uid
[ chmod u-s ]
[ chmod u-s ]
usb floppy
mount as /dev/sda edit fstab:
/dev/sda /mnt/floppy auto sync,user,noauto,nosuid,exec,nodev 0 0
mount as /dev/sda edit fstab:
/dev/sda /mnt/floppy auto sync,user,noauto,nosuid,exec,nodev 0 0
vim colors:
Use the example in the file : gvimrc_example.vim (which is in the vim directory , or the vim61 directory) and follow the directions in that file. (to find the vim directory , you can use the whereis command like this: [ whereis vim ]
These two files control the colors: synload.vim and colortest.vim . You can change syntax highlighting in these files after you do the above installation. In the vim directory there is a subdirectory called colors. In this directory are files that change the colors of vim. Read the readme.txt in that directory and it should be pretty clear what you need to do.
Use the example in the file : gvimrc_example.vim (which is in the vim directory , or the vim61 directory) and follow the directions in that file. (to find the vim directory , you can use the whereis command like this: [ whereis vim ]
These two files control the colors: synload.vim and colortest.vim . You can change syntax highlighting in these files after you do the above installation. In the vim directory there is a subdirectory called colors. In this directory are files that change the colors of vim. Read the readme.txt in that directory and it should be pretty clear what you need to do.
what is default file permission
[ umask ]
[ umask ]
print the file name of the terminal connected to standard input
[ tty ]
[ tty ]
untar : see extract archived files
X windows configuration (command line as root)
[ xf86config ]
[ xf86config ]
zipped tar : to unzip and untar a file named filename type: ( see also extract )
[ tar -xzf filename ]
[ tar -xzf filename ]
Perpetual PC's home page
Perpetual PC's link page