Get familiar with the VIM editor

Get familiar with the VIM editor

This text will provide you information about the Linux / Unix vi text editor and it's options.


SYNTAX

vi [ -| -s ] [-l] [-L] [-R] [ -r [ filename ] ] [-S] [-t tag] [-v] [-V] [-x] [-w] [-n ] [-C] [+command | -c command ] filename

- | -s Suppress all interactive user feedback. This is useful when processing editor scripts.

-l Set up for editing LISP programs.

-L List the name of all files saved as the result of an editor or system crash.

-R Readonly mode; the readonly flag is set, preventing accidental overwriting of the file.

-r filename Edit filename after an editor or system crash. (Recovers the version of filename that was in the buffer when the crash occurred.)

-S This option is used in conjunction with the -t tag option to tell vi that the tags file may not be sorted and that, if the binary search (which relies on a sorted tags file) for tag fails to find it, the much slower linear search should also be done. Since the linear search is slow, users of large tags files should ensure that the tags files are sorted rather than use this flag. Creation of tags files normally produces sorted tags files. See ctags for more information on tags files.

-t tag Edit the file containing the tag, tag, and position the editor at its definition.

-v Start up in display editing state using vi . You can achieve the same effect by simply typing the vi command itself.

-V Verbose. When ex commands are read by means of standard input, the input will be echoed to standard error. This may be useful when processing ex commands within shell scripts.

-x Encryption option; when used, vi simulates the X command of ex and prompts the user for a key. This key is used to encrypt and decrypt text using the algorithm of the crypt command. The X command makes an educated guess to determine whether text read in is encrypted or not. The temporary buffer file is encrypted also, using a transformed version of the key typed in for the -x option. If an empty encryption key is entered (that is, if the return key is pressed right after the prompt), the file will not be encrypted. This is a good way to decrypt a file erroneously encrypted with a mistyped encryption key, such as a backspace or undo key.

-wn Set the default window size to n. This is useful when using the editor over a slow speed line.

-C Encryption option; same as the -x option, except that vi simulates the C command of ex . The C command is like the X command of ex , except that all text read in is assumed to have been encrypted.

+command | -c command Begin editing by executing the specified editor
command (usually a search or positioning command).
filename The file to be edited.


USER COMMANDS

Arrow keys Move cursor

hjkl Same as arrow keys

itextESC Insert text

cwnewESC Change word to new

easESC pluralize word (end of word; append s; escape from input state)

x delete a character

dw delete a word

dd delete a line

3dd deletes 3 lines

u undo previous change

ZZ exit vi , saving changes

:q!CR quit, discarding changes

/textCR search for text

^U ^D scroll up or down

:cmdCR any ex or ed command

ESC end insert or incomplete command

DEL (delete or rubout) interrupts

:wCR write back changes

:w!CR forced write, if permission originally not valid

:qCR quit

:q!CR quit, discard changes

:e nameCR edit file name

:e!CR reedit, discard changes

:e + nameCR edit, starting at end

:e +nCR edit, starting at line n

:e #CR edit alternate file

:e! #CR edit alternate file, discard changes

:w nameCR write file name

:w! nameCR overwrite file name

:shCR run shell, then return

:!cmdCR run cmd, then return

:nCR edit next file in arglist

:n argsCR specify new arglist

^G show current file and line

:ta tagCR position cursor to tag

F forward screen

^B backward screen

^D scroll down half screen

^U scroll up half screen

nG go to the beginning of the specified line (end default), where n is a line number

/pat next line matching pat

?pat previous line matching pat

n repeat last / or ? command

N reverse last / or ? command

/pat/+n nth line after pat

?pat?-n nth line before pat

]] next section/function

[[ previous section/function

( beginning of sentence

) end of sentence

{ beginning of paragraph

} end of paragraph

% find matching ( ) or { }

^L clear and redraw window

^R clear and redraw window if ^L is -> key

zCR redraw screen with current line at top of window

z-CR redraw screen with current line at bottom of window

z.CR redraw screen with current line at center of window

/pat/z-CR move pat line to bottom of window

zn.CR use n-line window

^E scroll window down one line

^Y scroll window up one line

`` move cursor to previous context

\'\' move cursor to first non-white space in line

mx mark current position with the ASCII lower-case letter x

`x move cursor to mark x

\'x move cursor to first non-white space in line marked by x

H top line on screen

L last line on screen

M middle line on screen

+ next line, at first non-white space character

- previous line, at first non-white space character

CR return, same as +

down-arrow or j next line, same column

up-arrow or k previous line, same column

^ first non-white space character

0 beginning of line

$ end of line

l or -> forward

h or <- backward

^H same as <- (backspace)

space same as -> (space bar)

fx find next x

Fx find next x

tx move to character following the next x

Tx move to character following the previous x

; repeat last f, F, t, or T

, repeat inverse of last f, F, t, or T

n| move to column n

% find matching ( ) or { }

w forward a word

b back a word

e end of word

) to next sentence

} to next paragraph

( back a sentence

{ back a paragraph

W forward a blank-delimited word

B back a blank-delimited word

E end of a blank-delimited word

^H erase last character (backspace)

^W erase last word

erase your erase character, same as ^H (backspace)

kill your kill character, erase this line of input

\\ quotes your erase and kill characters

ESC ends insertion, back to command mode

CTRL-C interrupt, suspends insert mode

^D backtab one character; reset left margin of autoindent

^^D caret (^) followed by control-d (^D); backtab to beginning of line; do not reset left margin of autoindent

0^D backtab to beginning of line; reset left margin of autoindent

^V quote non-printable character

a append after cursor

A append at end of line

i insert before cursor

I insert before first non-blank

o open line below

O open line above

rx replace single character with x

RtextESC replace characters

d delete

c change

y yank lines to buffer

> left shift

< right shift

! filter through command

C change rest of line (c$)

D delete rest of line (d$)

s substitute characters (cl)

S substitute lines (cc)

J join lines

x delete characters (dl)

X delete characters before cursor dh)

Y yank lines (yy)

3yy yank 3 lines

3yl yank 3 characters

p put back text after cursor

P put back text before cursor \" .nr )I xp\"n

put from buffer x \" .nr )I xy\"n

yank to buffer x \" .nr )I xd\"n

delete into buffer x

u undo last change

U restore current line

. repeat last change \" .nr )I dp\"n

retrieve d\'th last delete

Linux: How to check the hardware

Linux: How to check the hardware

I've noticed there are no good tutorials on how to check what hardware you have installed on your machine. In Linux there are many ways doing this so it's not an issue but you have to know the needed commands.

I'll start step by step checking different devices on your computer but there is a tool wich shows all so if you don't want to read much just scroll down to the lshw command.

Check on the CPU:

Here is the command that will help you to see what CPU you have installed:

root@Linux ~# cat /proc/cpuinfo

This will print the whole needed information for your CPU. Here is an example:

processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 2
model name : Intel(R) Celeron(R) CPU 2.40GHz
stepping : 9
cpu MHz : 2400.485
cache size : 128 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe up pebs bts cid xtpr
bogomips : 4805.18
clflush size : 64

Checking VGA, LAN and wireless adapters, chipset etc:

root@Linux ~# lspci

Example result:

00:00.0 Host bridge: Intel Corporation 82865G/PE/P DRAM Controller/Host-Hub Interface (rev 02)
00:02.0 VGA compatible controller: Intel Corporation 82865G Integrated Graphics Controller (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev c2)
00:1f.0 ISA bridge: Intel Corporation 82801EB/ER (ICH5/ICH5R) LPC Interface Bridge (rev 02)
00:1f.1 IDE interface: Intel Corporation 82801EB/ER (ICH5/ICH5R) IDE Controller (rev 02)
00:1f.3 SMBus: Intel Corporation 82801EB/ER (ICH5/ICH5R) SMBus Controller (rev 02)
01:0d.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)

Checking the hard drives:

root@Linux ~# fdisk -l

Example:

isk /dev/hda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x90909090

Device Boot Start End Blocks Id System
/dev/hda1 1 13 104391 83 Linux
/dev/hda2 14 139 1012095 82 Linux swap / Solaris
/dev/hda3 140 9729 77031675 83 Linux

lshw

The easiest way to check all the hardware installed on your box is the lshw command.

Using this command you can see all the hardware. Use the update manager of your distribution to install it if the command line says that the command doesn't exist. The package name is lshw as well.

root@Linux ~# lshw

I won't paste an example for this command since the result is always too huge but it lists everything you need to know.

I hope it was helpful.

How To Check Which Port Is Listening or Open on Linux

How To Check Which Port Is Listening or Open on Linux

For some security reason you may configure SSH or any other protocol using different kind of port number on Linux server. Sometimes it?s important to know which ports are actually listen or open to the system network, it may open for network instruction or hacking.

Basically there are few methods to see which ports are open on Linux.

Option 1:
Check /etc/services file
planetmy:/ # cat /etc/services | grep xxx (xxx = port number)

If the command return no output mean no port configure to listen on the particular port number. For port SSH/22, you should be able to see:
ssh 22/tcp # SSH Remote Login Protocol
ssh 22/udp # SSH Remote Login Protocol

Option 2:
Use netstat command - Print network connections, routing tables, interface statistics, masquerade connections, and multi cast memberships.

planetmy:/ # netstat -nan | grep 22
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 7110/sshd

If the command output return ?LISTEN?, mean the particular port is open or listen on network.

Option 3:
use lsof command - list open files

planetmy:/ # lsof -i -n -P|grep 631
cupsd 17934 lp 0u IPv4 56540196 TCP *:631 (LISTEN)
cupsd 17934 lp 2u IPv4 56540197 UDP *:631

Option 4:
use nmap command - Network exploration tool and security scanner

planetmy:/ # nmap -sS -O 192.168.1.2
Starting nmap 3.50 ( http://www.insecure.org/nmap/ ) at 2008-09-12 10:13 GMT
Interesting ports on 192.168.1.2:
(The 1655 ports scanned but not shown below are in state: closed)
PORT STATE SERVICE
22/tcp open ssh
111/tcp open rpcbind
427/tcp open svrloc
631/tcp open ipp
Device type: general purpose
Running: Linux 2.4.X|2.5.X
OS details: Linux Kernel 2.4.0 - 2.5.20, Linux Kernel 2.4.18 - 2.5.70 (X86)
Nmap run completed ? 1 IP address (1 host up) scanned in 4.146 seconds

The output show the system is running SSH on port 22.

Option 5:
use telnet command - user interface to the TELNET protocol

planetmy:/ # telnet 192.168.1.2 22
Trying 192.168.1.2?
Connected to 192.168.1.2.
Escape character is ?^]?.
SSH-1.99-OpenSSH_4.2

The output show as above mean SSH port 22 is listening on the network

planetmy:/ # telnet 192.168.1.2 122
Trying 192.168.1.2?
telnet: connect to address 192.168.1.2: Connection refused

The output show as above mean port 122 is closed.

Thanks to:
http://www.freecodeclub.com/

Setting Up Your Own Station: A Free Radio Under Linux HowTo

Setting Up Your Own Station: A Free Radio Under Linux HowTo

1. Introduction

So, you want to create your own radio station, don’t you? This manual will help you become a DJ.

2. System Requirements

Minimal requirements for radio broadcasting through your own computer, most of which you are already aware of:

*

150 MHz processor, or better
*

32 MB RAM
*

cable, DSL, or any other kind of broadband internet

and a little free hard disk space for mp3s (which you are going to play).

OS:

*

Some up-to-date Linux distribution, kernel 2.2 or newer.

Software:

*

XMMS 1.2.x http://www.xmms.org/
*

LAME v3.x http://www.sulaco.org/mp3
*

Icecast 1.3.x http://www.icecast.org/
*

Liveice-XMMS. http://star.arm.ac.uk/~spm/software/liveice.html

If using Debian, you can also use:

apt-get install xmms icecast-server

to install xmms and Icecast server. According to LAME, you can use a program called Alien, to convert RPM pack into Debian pack. All you have to do is:

apt-get install alien

and then, as root:

alien package.rpm

to create .deb which you can install, using

dpkg –i

where the name of the Debian package is.

3. Installation

The installation should be rather right-minded. You already should have all packages you need, in order to make things work. If compiling from source, then you should compile and install the software as it is described in its documentation.

If using RedHat, or any of its relative ones you can search for RPM, and download and install it by

rpm –Uvh

where the name of the RPM, which you use is.

If using Debian, just write

apt-get install xmms

icecast-server

to install xmms and Icecast server. According to LAME, you can use a program called Alien, to convert RPM package into Debian package. Install it:

apt-get install alien

then you can use it as root:

alien package.rpm

and the packages can be installed by using

dpkg –i

followed by the package’s name. For example:

dpkg -i .deb

And don’t forget that you should be root to do most of the above. And now, after the installation of all programs you need we have to set them in order to work properly.

4. Configuration

First of all we should configure the Icecast server. Find the directory which contains the Icecast server configuration files (in my case it was /etc/icecast, and I suppose it’s the same if installed by RPM; if you compiled the program on your own, then you are prepared well enough to know where the settings should be) and there you should have many “.dist”-files. Now rename all that files by deleting the “.dist” part. For example if the file name is “icecast.conf.dist” the new one should be “icecast.conf”. If there are no more “.dist”-files then you are doing well.

Now open icecast.conf with your favorite editor. The configuration is rather right-minded and simple, but anyway I’ll guide you through it. Near the beginning of the file you’ll find location/information fields:

location Just west of Mars

rp_email kirk@enterprise.space

server_url http://www.icecast.org/

fill them with the information, that you want people to see, when visiting your web-radio-station.

The next section you have to look at is the one for the server limit:

max_clients 900

max_clients_per_source 900

max_sources 10

max_admins 5

throttle 10.0

For most of the users this is much more than enough. Just set the parameters according to the speed of your Internet connection. Probably you’ll prefer

max_clients

and

max_clients_per_source

to be set at 10, and the rest you can leave the way it is. Now go down the file while you reach:

encoder_password hackme

admin_password hackme

oper_password hackme

If installed the Icecast server under Debian, or support of encrypted passwords enabled, you should crypt the password in this file using program, called mkpasswd (which probably you already have installed on your system). To do this use:

mkpasswd --crypt

Then copy and paste the result in the file. It should look like this:

encoder_passwd --WZKu0fXj3bQ

admin_passwd --WZKu0fXj3bQ

oper_passwd --WZKu0fXj3bQ

No matter which way of installation you made, you should change the password into something else than “hackme”. In the common case the three passwords should be the same. Remember the password you use, because you will use it latter during the configuration of the Liveice-XMMS.

Go down the file again and find:

console_mode 0

change the value at 3, that way the loading will be in text mode.

Usually you don’t have to change the rest of the configuration file. The advanced users can look through the rest of the settings.

Now, let’s configure the Liveice-XMMS:

Restart the XMMS, in order to make it possible to notice that there is another plugin. Make right click on the XMMS and choose Preferences. Go to Effect/General Plugins. In the list under Effect Plugins you should find Liveince. In case you can’t find it check out the Liveice-XMMS installation. After choosing Liveince, click on Configure.

Most of these audio format settings are standard, so you won’t have to change them much. Change the “Encoder type” to ‘Lame’, and the “executable name” to ‘Lame’. If already have any version of Lame on your machine, then set the path to it. Under “Description” you can consider the exact changes by yourself.

Go to Server and change the “Encoder Password” into the one that’s written in the Icecast configuration (and I told you to remember). You shouldn't type the password in encrypted mode if you have encrypted it.

Now everything is set and ready. Click OK. Check “Use Plugins” in the dialog “Preferences”, which should still be in front of you, and click OK again.

In terminal window type ‘icecast’ and press Enter. You should see how it’s getting started and proceeds into text mode.

If you are listening to a song, stop it and play it again.

Nothing went wrong…? There wasn’t big BANG!!! I hope so!

Ask a friend to connect to your IP through XMMS or any other mp3-player at http://yourcomputer:8000 … there should be music playing! If this is not happening, check out the FAQ to solve the problem.

If everything is OK, congratulations – you are now a DJ!

5. FAQ

Make sure that Icecast works. If the problems are still there, go to the conf file, at the place where you changed console_mode to 3, and change it back to 0 (that way you can receive some debug messages). You should be connecting as source, other ways check the Liveice settings. If you are connected as ‘source’, or as ‘encoder’, and your friend is trying to connect, but you don’t receive a message for this, then the problem is not in you!

Linux advanced commands

Linux advanced commands

Command		Description
	apropos whatis	Show commands pertinent to string. See also threadsafe
	man -t man | ps2pdf - > man.pdf	make a pdf of a manual page
	which command	Show full path name of command
	time command	See how long a command takes
	time cat	Start stopwatch. Ctrl-d to stop. See also sw
	nice info	Run a low priority command (The "info" reader in this case)
	renice 19 -p $$	Make shell (script) low priority. Use for non interactive tasks
dir navigation
	cd -	Go to previous directory
	cd	Go to $HOME directory
	(cd dir && command)	Go to dir, execute command and return to current dir
	pushd .	Put current dir on stack so you can popd back to it
file searching
	alias l='ls -l --color=auto'	quick dir listing
	ls -lrt	List files by date. See also newest and find_mm_yyyy
	ls /usr/bin | pr -T9 -W$COLUMNS	Print in 9 columns to width of terminal
	find -name '*.[ch]' | xargs grep -E 'expr'	Search 'expr' in this dir and below. See also findrepo
	find -type f -print0 | xargs -r0 grep -F 'example'	Search all regular files for 'example' in this dir and below
	find -maxdepth 1 -type f | xargs grep -F 'example'	Search all regular files for 'example' in this dir
	find -maxdepth 1 -type d | while read dir; do echo $dir; echo cmd2; done	Process each item with multiple commands (in while loop)
	find -type f ! -perm -444	Find files not readable by all (useful for web site)
	find -type d ! -perm -111	Find dirs not accessible by all (useful for web site)
	locate -r 'file[^/]*\.txt'	Search cached index for names. This re is like glob *file*.txt
	look reference	Quickly search (sorted) dictionary for prefix
	grep --color reference /usr/share/dict/words	Highlight occurances of regular expression in dictionary
archives and compression
	gpg -c file	Encrypt file
	gpg file.gpg	Decrypt file
	tar -c dir/ | bzip2 > dir.tar.bz2	Make compressed archive of dir/
	bzip2 -dc dir.tar.bz2 | tar -x	Extract archive (use gzip instead of bzip2 for tar.gz files)
	tar -c dir/ | gzip | gpg -c | ssh user@remote 'dd of=dir.tar.gz.gpg'	Make encrypted archive of dir/ on remote machine
	find dir/ -name '*.txt' | tar -c --files-from=- | bzip2 > dir_txt.tar.bz2	Make archive of subset of dir/ and below
	find dir/ -name '*.txt' | xargs cp -a --target-directory=dir_txt/ --parents	Make copy of subset of dir/ and below
	( tar -c /dir/to/copy ) | ( cd /where/to/ && tar -x -p )	Copy (with permissions) copy/ dir to /where/to/ dir
	( cd /dir/to/copy && tar -c . ) | ( cd /where/to/ && tar -x -p )	Copy (with permissions) contents of copy/ dir to /where/to/
	( tar -c /dir/to/copy ) | ssh -C user@remote 'cd /where/to/ && tar -x -p'	Copy (with permissions) copy/ dir to remote:/where/to/ dir
	dd bs=1M if=/dev/sda | gzip | ssh user@remote 'dd of=sda.gz'	Backup harddisk to remote machine
rsync (Use the --dry-run option for testing)
	rsync -P rsync://rsync.server.com/path/to/file file	Only get diffs. Do multiple times for troublesome downloads
	rsync --bwlimit=1000 fromfile tofile	Locally copy with rate limit. It's like nice for I/O
	rsync -az -e ssh --delete ~/public_html/ remote.com:'~/public_html'	Mirror web site (using compression and encryption)
	rsync -auz -e ssh remote:/dir/ . && rsync -auz -e ssh . remote:/dir/	Synchronize current directory with remote one
ssh (Secure SHell)
	ssh $USER@$HOST command	Run command on $HOST as $USER (default command=shell)
	ssh -f -Y $USER@$HOSTNAME xeyes	Run GUI command on $HOSTNAME as $USER
	scp -p -r $USER@$HOST: file dir/	Copy with permissions to $USER's home directory on $HOST
	ssh -g -L 8080:localhost:80 root@$HOST	Forward connections to $HOSTNAME:8080 out to $HOST:80
	ssh -R 1434:imap:143 root@$HOST	Forward connections from $HOST:1434 in to imap:143
wget (multi purpose download tool)
	(cd cmdline && wget -nd -pHEKk http://www.pixelbeat.org/cmdline.html)	Store local browsable version of a page to the current dir
	wget -c http://www.example.com/large.file	Continue downloading a partially downloaded file
	wget -r -nd -np -l1 -A '*.jpg' http://www.example.com/dir/	Download a set of files to the current directory
	wget ftp://remote/file[1-9].iso/	FTP supports globbing directly
	wget -q -O- http://www.pixelbeat.org/timeline.html | grep 'a href' | head	Process output directly
	echo 'wget url' | at 01:00	Download url at 1AM to current dir
	wget --limit-rate=20k url	Do a low priority download (limit to 20KB/s in this case)
	wget -nv --spider --force-html -i bookmarks.html	Check links in a file
	wget --mirror http://www.example.com/	Efficiently update a local copy of a site (handy from cron)
networking (Note ifconfig, route, mii-tool, nslookup commands are obsolete)
	ethtool eth0	Show status of ethernet interface eth0
	ethtool --change eth0 autoneg off speed 100 duplex full	Manually set ethernet interface speed
	iwconfig eth1	Show status of wireless interface eth1
	iwconfig eth1 rate 1Mb/s fixed	Manually set wireless interface speed
	iwlist scan	List wireless networks in range
	ip link show	List network interfaces
	ip link set dev eth0 name wan	Rename interface eth0 to wan
	ip link set dev eth0 up	Bring interface eth0 up (or down)
	ip addr show	List addresses for interfaces
	ip addr add 1.2.3.4/24 brd + dev eth0	Add (or del) ip and mask (255.255.255.0)
	ip route show	List routing table
	ip route add default via 1.2.3.254	Set default gateway to 1.2.3.254
	tc qdisc add dev lo root handle 1:0 netem delay 20msec	Add 20ms latency to loopback device (for testing)
	tc qdisc del dev lo root	Remove latency added above
	host pixelbeat.org	Lookup DNS ip address for name or vice versa
	hostname -i	Lookup local ip address (equivalent to host `hostname`)
	whois pixelbeat.org	Lookup whois info for hostname or ip address
	netstat -tupl	List internet services on a system
	netstat -tup	List active connections to/from system
windows networking (Note samba is the package that provides all this windows specific networking support)
	smbtree	Find windows machines. See also findsmb
	nmblookup -A 1.2.3.4	Find the windows (netbios) name associated with ip address
	smbclient -L windows_box	List shares on windows machine or samba server
	mount -t smbfs -o fmask=666,guest //windows_box/share /mnt/share	Mount a windows share
	echo 'message' | smbclient -M windows_box	Send popup to windows machine (off by default in XP sp2)
text manipulation (Note sed uses stdin and stdout, so if you want to edit files, append newfile)
	sed 's/string1/string2/g'	Replace string1 with string2
	sed 's/\(.*\)1/\12/g'	Modify anystring1 to anystring2
	sed '/ *#/d; /^ *$/d'	Remove comments and blank lines
	sed ':a; /\\$/N; s/\\\n//; ta'	Concatenate lines with trailing \
	sed 's/[ \t]*$//'	Remove trailing spaces from lines
	sed 's/\([\\`\\"$\\\\]\)/\\\1/g'	Escape shell metacharacters active within double quotes
	seq 10 | sed "s/^/ /; s/ *\(.\{7,\}\)/\1/"	Right align numbers
	sed -n '1000p;1000q'	Print 1000th line
	sed -n '10,20p;20q'	Print lines 10 to 20
	sed -n 's/.*