Redeeming Myself...

Configuring Network Printer in Linux (Fedora)

2012-03-03T00:02:00.000+05:30

Well that's another tedious task we have while configuring our system ;)

Lets configure one

First and foremost thing is your firewall. Make sure the firewall is down else you will not be able to search your printer in the network.

Every command needs to be executed as "root". Here we will disable iptables.

Code:

systemctl stop iptables.service

In other/older versions the command may be something as follows.

Code:

/etc/init.d/iptables stop

Mine is Fedora 16

Next, you have to install cups.

Code:

yum install cups

And start the service. By default it will start but just in case.

Code:

systemctl start cups.service

Point your web browser to http://localhost:631 and make sure the cups service is running.

Now, we can configure the printer either through cups or the system default printer configuration.

System Tools > System Settings > Printers

Code:

system-config-printer

Click on Add

Select Network Printer and double click on Find Network Printer

After few seconds the printers on your network should get displayed.

Select your printer and it should display the IP address and Port

Click Forward

It will search for drivers and you should get the driver page.

Select the options as follows. Mine is HP, select whichever is yours and click Forward

If the drivers are not available, it may download and install. So make sure you have an active internet connection.

And Apply.

If the Cups service is not running, when invoking the "Printer" gui, the Add button may not be enabled.

Pidgin Messenger @ Office

2012-02-27T08:19:00.001+05:30

Got approval for using Fedora @ office. But what about the MS Office Communicator or Cisco Webex Connect? How do I use it with Fedora?

No problem. Use Pidgin Messenger!

I need to configure Cisco Webex Connect.

Install Pigdin and Pidgin Sipe

Code:

yum install pidgin

Code:

yum install pidgin-sipe

For Ubuntu use "apt-get install" command instead.

Start Pidgin

Account > Manage Account > Add

In the Basic Tab enter the required info

Click Add and you are good to go!

Once added from the main window enable the account

Accounts > Enable Accounts > Select Your Account

You can also configure MS Communicator.

Protocol that needs to be selected is "Office Communicator"

IPSec Linux and Solaris (Cont...)

2012-02-26T18:08:00.001+05:30

Continued from IPSec Linux & Solaris...

A working IPSec configuration between Solaris 9 and Fedora.

Solaris Machine <> 172.50.20.100 (bge0)

Tunnel IP <> 198.168.1.100 (tun0)

Linux Machine <> 172.50.20.200 (eth0)

Tunnel IP <> 198.168.1.200 (tun0)

Like I've already mentioned, keying can be done manually or auto. Here we will use auto keying i.e. with the help of the IKE daemons.

Linux Configuration

IPSec tools needs to downloaded and installed.

IPSec Installation

Installation of IPSec is fairly simple, just like installing any other application. You need to be root for installation or make sure your admin has given you sudo privileges.

Here, I will provide some info on installing the ipsec-tools on Fedora 16.

The command is ofcourse "yum install ipsec-tools" for Fedora, "apt-get install ipsec-tools" on Ubuntu etc

Code:

root > yum install ipsec-tools
Loaded plugins: langpacks, presto, refresh-packagekit
fedora/group_gz                                                                                                     | 431 kB     00:01     
fedora-cinnamon                                                                                                     | 2.9 kB     00:00     
updates/metalink                                                                                                    | 3.3 kB     00:00     
updates                                                                                                             | 4.5 kB     00:00     
updates/primary_db                                                                                                  | 4.0 MB     00:59     
updates/group_gz                                                                                                    | 431 kB     00:08     
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package ipsec-tools.i686 0:0.8.0-2.fc16 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

===========================================================================================================================================
 Package                            Arch                        Version                                Repository                     Size
===========================================================================================================================================
Installing:
 ipsec-tools                        i686                        0.8.0-2.fc16                           fedora                        364 k

Transaction Summary
===========================================================================================================================================
Install       1 Package

Total download size: 364 k
Installed size: 364 k
Is this ok [y/N]: y
Downloading Packages:
ipsec-tools-0.8.0-2.fc16.i686.rpm                                                                                   | 364 kB     00:01     
Running Transaction Check
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing : ipsec-tools-0.8.0-2.fc16.i686                                                                                           1/1 

Installed:
  ipsec-tools.i686 0:0.8.0-2.fc16                                                                                                          

Complete!
root >

Just do a verification if you have all these in your machine

Code:

root > which racoon
/usr/sbin/racoon
root > which setkey
/sbin/setkey
root > ls -lrtd /etc/racoon/
drwxr-xr-x. 4 root root 4096 Feb 26 13:22 /etc/racoon/

Note : Older versions of IPSec will have the /etc/ipsec-tools folder instead of /etc/racoon. It doesn't matter really!

All the configuration in Linux is present at /etc/racoon folder.

We will do 2 levels of configuration.

1. Setting up the raccoon

2. Setting up the policies.

Raccoon Configuration

We will need to add/modify the /etc/racoon/racoon.conf file to suit our requirements which is read by the racoon daemon.

/etc/racoon/racoon.conf

Code:

#Racoon will use this file for pre_shared_key autentication#
path pre_shared_key "/etc/racoon/psk.txt";

remote 172.50.20.100 {
   exchange_mode main;
   lifetime time 360 min;
   nonce_size 20;
   proposal {
     dh_group 5;
     encryption_algorithm 3des;
     hash_algorithm md5;
     authentication_method pre_shared_key;
   }
}

#sainfo any
sainfo address 198.168.1.100 any address 198.168.1.200 any
{
   pfs_group 5;
   encryption_algorithm aes;
   authentication_algorithm hmac_md5;
   compression_algorithm deflate;
}

As you can see the pre-shared key is present at /etc/racoon/psk.txt

/etc/racoon/psk.txt

Code:

172.50.20.100  0x1234567890

That completes the phase 1.

Let us set-up some policies here and then go to the Solaris box.

Policies

Now we set up the required policies that needs to matched for the traffic. The command used is "setkey". Let us put all the configuration in /etc/racoon/setkey.conf

/etc/racoon/setkey.conf

Code:

spdadd 172.50.20.200 172.50.20.100 any -P out ipsec 
  esp/tunnel/198.168.1.200-198.168.1.100/require;

spdadd 172.50.20.100 172.50.20.200 any -P in ipsec
  esp/tunnel/198.168.1.100-198.168.1.200/require;

Use the setkey command to setup the policies as shown.

Code:

root > setkey -f /etc/racoon/setkey.conf

Verify if your policies are properly loaded using -PD option.

Code:

root > setkey -PD
172.50.20.100[any] 172.50.20.200[any] 255
 fwd prio def ipsec
 esp/tunnel/198.168.1.100-198.168.1.200/require
 created: Feb 26 17:26:14 2012  lastused:                     
 lifetime: 0(s) validtime: 0(s)
 spid=18 seq=1 pid=9246
 refcnt=1
172.50.20.100[any] 172.50.20.200[any] 255
 in prio def ipsec
 esp/tunnel/198.168.1.100-198.168.1.200/require
 created: Feb 26 17:26:14 2012  lastused:                     
 lifetime: 0(s) validtime: 0(s)
 spid=8 seq=2 pid=9246
 refcnt=1
172.50.20.200[any] 172.50.20.100[any] 255
 out prio def ipsec
 esp/tunnel/198.168.1.200-198.168.1.100/require
 created: Feb 26 17:26:14 2012  lastused:                     
 lifetime: 0(s) validtime: 0(s)
 spid=1 seq=0 pid=9246
 refcnt=1

As you can see the kernel adds a default forward policy. In older versions, we had to add it manually.

There is a hell lot of information I want to add along with this regarding the setkey command, the parameters in racoon configuration, the algorithms used etc. May be in another post!

Before going to the Solaris box, let us start the racoon daemon.

Code:

root > /etc/init.d/racoon start
Starting racoon (via systemctl):                           [  OK  ]

Just confirm it using pgrep

Code:

root > pgrep racoon
9278

So far everything looks fine! Let us move onto the Solaris Box.

Solaris

In Solaris, ike is the daemon responsible for what racoon does in Linux. ipseckey and ipsecconf is responsible for what setkey does.

So, like racoon.conf here we have the ike configuration which is present at

/etc/inet/ike/config

Code:

#Phase 1
p1_lifetime_secs 21600
p1_nonce_len 20

p1_xform {auth_method preshared oakley_group 5 auth_alg md5 encr_alg 3des }

#Phase 2
p2_pfs 5

{
   label "172.50.20.100 - 172.50.20.200"
   local_id_type IP
   local_addr 172.50.20.100
   remote_addr 172.50.20.200
}

The preshared key needs to added at /etc/inet/secret/ike.preshared

/etc/inet/secret/ike.preshared

Code:

172.50.20.200  1234567890

Now we need to set up the policy like we did in Linux. Let us have the policy in /etc/inet/ike/ipsecconf.conf

/etc/inet/ike/ipsecconf.conf

Code:

{ 
  tunnel tun0 
  negotiate tunnel laddr 198.168.1.100/32 raddr 198.168.1.200/32 dir out 
} ipsec { 
  encr_algs aes-cbc(128..256) encr_auth_algs hmac-md5(128) sa shared 
}

Unlike the Linux policy, we need only one in this case, basically because it supports "both" in direction.

Load the policy using the following command

Code:

root > ipsecconf -f /etc/inet/ike/ipsecconf.conf

Verify if your policies are properly loaded.

Code:

root > ipsecconf -ln
#INDEX tun0,1{ tunnel tun0   negotiate tunnel laddr 198.168.1.100/32 raddr 198.168.1.200/32 
dir out } ipsec {   encr_algs aes-cbc(128..256) encr_auth_algs hmac-md5(128) 
sa shared }

Now start the ike daemon and verify it.

Code:

root > /usr/lib/inet/in.iked

Try pinging the tunnels from either boxes.

Use the command "setkey -D" to see if the associations are created on the Linux box and "ipseckey dump" on Solaris box.

Will add more information later!

Have a good day!

Date command in Linux

2012-01-04T08:28:00.000+05:30

Man page of date will give you more info than anything else, it is a very descriptive one.

I wanted to hightlight few of the options used and thier alternatives, mainly the option "-d". Why because it looks like solaris version of date does not have "-d" option.

The man page says

-d, --date=STRING

display time described by STRING, not `now'

Lets take few examples

Firing the date command would give you the date

Code:

root@bt > date
Wed Jan  4 07:52:17 IST 2012

Do you want to customize this? No problem. Use the format control. There are like more than 20 format control options.

Say, you want the date in DD/MM/YYYY format

Code:

root@bt > date '+%d/%m/%Y'
04/01/2012

%d day of month (e.g, 01)

%m month (01..12)

%Y year

Want the current date in seconds since the epoch? Use "+%s" option

Code:

root@bt > date '+%s'
1325644010

%s seconds since 1970-01-01 00:00:00 UTC

As you can see, "+" is mandatory which is followed by the format specifier.

To set/change the system date, use the "-s" option.

-s, --set=STRING

set time described by STRING

Code:

root@bt > date
Wed Jan  4 08:21:47 IST 2012

root@bt > date -s "Mon Dec 31 00:00:00 IST 1990"
Mon Dec 31 00:00:00 IST 1990

root@bt > date
Mon Dec 31 00:00:01 IST 1990

Now, what does "-d" option do? Hmmm, if you see we were dealing with current system date till now. What if you want to do the same with some other date? Well, that is where "-d" option comes to the rescue!

Say, you want to find the seconds since epoch till December 31 1990

Code:

root@bt > date -d "Dec 31 1990" '+%s'
662581800

You want to format a date given to you in "31 Dec 1990" to MM-DD-YY

Code:

root@bt > date -d "31 Dec 1990" '+%m-%d-%y'
12-31-90

Cool right? Now, the "-d" option is not available in Solaris (not sure about 10 though).

Here is an alternative in awk for achieving the above

To get the time in seconds

Code:

root@bt > echo "Dec 31 1990" | nawk 'BEGIN{month="JanFebMarAprMayJunJulAugSepOctNovDec"}
{ print mktime($3" "int((index(month,$1)/3))+1" "$2" 00 00 00") }'
662581800

Code:

root@bt > echo "31 Dec 1990" | nawk 'BEGIN{month="JanFebMarAprMayJunJulAugSepOctNovDec"}
{ print int((index(month,$2)/3))+1"-"$1"-"substr($3,3) }'
12-31-90

We can practically do anything in awk! Check the right side link for AWK tutorial.

One more thing before we go, how do we convert the seconds to date?

Say, I have 662581800 (from our previous example), I want to convert it to actual date format

Code:

root@bt > date -d @662581800
Mon Dec 31 00:00:00 IST 1990

Note the "@" symbol before the seconds.

Also note that I have used nawk instead of awk, because in solaris the awk version is pretty old and it is kind of useless. Either use "nawk" or awk from this path "/usr/xpg4/bin/awk" in solaris.

Good Day!

Command Substitution in Linux

2012-01-03T01:29:00.000+05:30

In Linux, we do a lot of onliners on the shell. Something like,

Code:

root@bt > date
Tue Jan  3 01:19:19 IST 2012

Now if we want to store this date into a variable, what do we do?

There are 2 ways in which we can achieve this i.e. command substitution

One way, using backticks i.e. `

Code:

root@bt > var=`date`
root@bt > echo $var
Tue Jan 3 01:20:47 IST 2012

Other way is using $(...)

Code:

root@bt > var=$(date)
root@bt > echo $var
Tue Jan 3 01:21:18 IST 2012

Command line or script, you can use it anywhere you want. I prefer the second way!

Note, there is no space between var = and the command. Why so? Because that is how it should be.
That is the syntax. If you have a space in between you will see strange errors.
Let us try it once with a space inbetween,

Code:

root@bt > var =$(date)
No command 'var' found, did you mean:
 Command 'jar' from package 'openjdk-6-jdk' (main)
 ...
 Command 'par' from package 'par' (universe)
var: command not found

Oops, we don't want that now, do we?

Good Day!

File Creation Time in Linux

2012-01-01T20:53:00.000+05:30

Actually, the creation time of any inode is(was) not stored anywhere. I wonder why they did that. Normally we get to see only the following :

ctime - change time
mtime - modification time
atime - access time

What about crtime - creation time?

But things have changed now. We can get the file creation time if your filesystem type is ext4.

First lets see how we can get the details of a file. There is a command called "stat" - display file or filesystem status.

Code:

root@bt > stat somefile
File: `somefile'
Size: 149        Blocks: 8          IO Block: 4096   regular file
Device: 804h/2052d Inode: 211582      Links: 1
Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2012-01-01 20:21:15.276575811 +0530
Modify: 2012-01-01 20:21:14.256570755 +0530
Change: 2012-01-01 20:21:14.256570755 +0530

"somefile" is a normal ascii file. A "stat" on the file will give you all these details. You can also customize the output. Let us say you just want the size of the file.

Code:

root@bt > ls -lrt somefile
-rw-r--r-- 1 root root 149 2012-01-01 20:21 somefile
root@bt > stat -c %s somefile
149

-f will give you information about the file system.

Code:

root@bt > stat -f /dev/sda4
File: "/dev/sda4"
  ID: 0        Namelen: 255     Type: tmpfs
Block size: 4096       Fundamental block size: 4096
Blocks: Total: 255610     Free: 255524     Available: 255524
Inodes: Total: 214563     Free: 213660

Now, the -t option is interesting. If you want to get all this info in one line, use this option. This will be very helpful when it comes to scripts where we use stat to get various information into a variable and do some calculation etc.

Code:

root@bt > stat -t -f /dev/sda4
/dev/sda4 0 255 1021994 4096 4096 255610 255524 255524 214563 213660

So, we didn't get the file creation time yet! What do we do for that?
Ok, here it is
1. You will need a ext4 filesystem.
2. You will also need the debugfs -ext2/ext3/ext4 file system debugger utility which is normally available with any distros. If you don't have it, then simply install it.

Check List
Lets get some info on / and /dev/sda4.

Code:

root@bt > df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda4              14G   10G  2.6G  80% /
none                  999M  344K  999M   1% /dev

Code:

root@bt > mount | grep sda4
/dev/sda4 on / type ext4 (rw,errors=remount-ro)

Cool! It is on ext4.

Once you have all that, then all you have to do is run the following command

Code:

root@bt >  debugfs -R 'stat /root/Desktop/somefile' /dev/sda4
debugfs 1.41.11 (14-Mar-2010)
Inode: 211582   Type: regular    Mode:  0644   Flags: 0x80000
Generation: 1690641204    Version: 0x00000000:00000001
User:     0   Group:     0   Size: 149
File ACL: 0    Directory ACL: 0
Links: 1   Blockcount: 8
Fragment:  Address: 0    Number: 0    Size: 0
ctime: 0x4f0072e2:3d2bd60c -- Sun Jan  1 20:21:14 2012
atime: 0x4f0072e3:41f0d90c -- Sun Jan  1 20:21:15 2012
mtime: 0x4f0072e2:3d2bd60c -- Sun Jan  1 20:21:14 2012
crtime: 0x4f0072e2:3d2bd60c -- Sun Jan  1 20:21:14 2012
Size of extra inode fields: 28
EXTENTS:
(0): 772301
(END)

Do you see the crtime? Wow!

bc - a powerful calculator

2012-01-01T09:05:00.000+05:30

"An arbitrary precision calculator language' - this is what the man page says. This is fairly a simple tool in term of usage.
For instance :- Just type in "bc" in your shell prompt and you have the tool running.

Code:

root@bt > bc
bc 1.06.95
Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.

22/7
3

See the "22/7", that is what I have typed in and there is the result. You can also use this like an one liner.

Code:

root@bt > echo " 22/7 " | bc
3

Hmmm I know, the decimals are missing right? No problem, we just need to tell the "bc" to print the decimals. Use "scale" for that purpose.

Code:

root@bt > echo " scale=5; 22/7 " | bc
3.14285

Wow! happy now? ;)

If you go thru the man page, you can see that whatever you do in C using the math lib, you can do it using "bc" as well. What got my attention is that, we can actually have our own functions written and call it.

Code:

root@bt > echo "define foo(a,b){ return a+b }; print foo(10,20)" | bc
30

Cool right? I mean look at the flexibility this small tool is providing you. Well, can't call this a small tool now, can we?

Just for information, I found another program "calc".

Code:

root@bt > calc
C-style arbitrary precision calculator (version 2.12.3.3)
Calc is open software. For license details type:  help copyright
[Type "exit" to exit, or "help" for help.]

; 22/7
~3.14285714285714285714
;

Check this out!

Code:

root@bt > bc
bc 1.06.95
Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.

scale=100
22/7
3.142857142857142857142857142857142857142857142857142857142857142857\
1428571428571428571428571428571428

I did try with a scale of 1000 and it worked!

Excellent Tutorial on "bc"

Good Day!

match() funtion in awk has a 3rd argument

2011-10-30T22:29:00.000+05:30

Just came to know that the function match() in awk has a third argument!
The third argument is an array where you can capture the search results.

For eg:-

Code:

root@bt > cat infile
ajith & ajeesh
root@bt> awk '{match($0,"([a-z]*) & ([a-z]*)",arr); print arr[1]" : "arr[2] }' infile
ajith : ajeesh

([a-z]*) => will capture the first element of the array
&
([a-z]*) => will capture the second element of the array

And the array name here is "arr"

Experimenting BackTrack codename "Revolution"

2011-08-22T00:55:00.000+05:30

BackTrack (release 5) is another Linux distro. Pretty fancy stuff for a guy like me, ;) I mean the stylish logo and themes and all, it looks good and pro. It is an Ubuntu derivative maintained by a group known as Offensive Security, security related of course.

I happen to see one of the webcasts by these guys, a real life hacking, wow pretty cool! The way they root into the database server, awesome!

BackTrack - how is it?

1. I tried the 64 bit version first. It was kind of slow. Actually the display driver was not installed. I didn't know to configure my wlan, I mean I was searching for the settings but just couldn't find it. So thought of scrapping it. I had a bad experience with Fedora 15 64 bit.

2. Installed the 32 bit version. Well, installation was easy but lets compare it with Fedora and Windows 7. The user inputs were less. For a newbie, the partition part may be a little difficult as in to create a ext4 partition with swap space etc.

I already had Fedora 13 installed (which btw got screwed up big time due to which I was forced to try new OS. hee hee). So when I started installing Fedora 15, it detected Fedora 13 and opted for upgrade or new installation. Else the same partition step would've hit. User inputs were less nothing big.

Issue with Fedora 15 64 bit : I was so adamant that I wanted only Fedora in my system, somehow I got used it (no big deal!). So thought of upgrading it to Fedora 15. But then I came across the 64 bit version, hmmm lets try that. 3-4 times I installed it. It wasn't stable at all. Many a times it got screwed while I was trying to change some display configurations.

Windows 7 installation was a piece of cake. Did an upgrade from Vista. Hardly I entered anything.

3. After bootup, we need to login and start the x server, that is not user friendly. It is a matter of 2 steps, but still.

4. Then I have to connect to the wlan manually, somehow it is not happening for me thought I have configured to connect automatically. Still trying to figure it out.

5. Installed the latest nVidia drivers, but the configurations though saved is kind of useless. Next time I bootup, I need to change the display settings.

6. Interface and themes are cool and catchy. And there are may superb tools for network security. This OS is basically used for PenTest (Penetration Testing).

Over all : I don't know, I am still exploring. ;)

IPSec Linux & Solaris

2011-03-27T10:27:00.000+05:30

Yes, I got a chance to work with IPSec in Linux and Solaris. Well, we managed to get a working connection between Linux and Solaris, so in case any of you got any doubts do contact me. I do not know much about the certificates though.

Just an overview of what is IPSec

IPsec is an extension to the IP protocol which provides security to the IP and the upper-layer protocols. It was first developed for the new IPv6 standard and then “backported” to IPv4.

IPsec uses two different protocols - AH and ESP - to ensure the authentication, integrity and confidentiality of the communication. It can protect either the entire IP datagram or only the upper-layer protocols. The appropiate modes are called tunnel mode and transport mode. In tunnel mode the IP datagram is fully encapsulated by a new IP datagram using the IPsec protocol. In transport mode only the payload of the IP datagram is handled by the IPsec protocol inserting the IPsec header between the IP header and the upper-layer protocol header. - www.ipsec-tools.sourceforge.net

Linux and Solaris uses entirely different packages and commands. We can have the keys exchanged automatically(more secure) or by manual preshared key(less secure). For the auto key exchange, Linux uses a "racoon" and Solaris used "ike daemon".

Similarly, for setting up the SA (security association - SAD - Security Association Database) and Policies, Linux used "setkey" where as Solaris uses "ipseckey" and "ipsecconf". The syntax and rules may be different but comparable.

And making it work between Linux and Solaris - that was one hell of a challenge we had!

Added more information at IPSec Linux & Solaris (Cont)

Passing variables to sed

2010-12-24T00:53:00.001+05:30

Using "sed" in command line is fine. We may not make much mistakes in the syntax.

Normally, we use single quotes around sed which works well.

Code:

root@bt> sed 's/genius/dump/g' infile

But if you want to use/pass variables to sed, you will need to use double quotes.

Code:

root@bt> var=genius
root@bt> sed "s/$var/dump/g" infile

Got it? Good!

Have a nice day!

grep grep grep

2010-11-21T01:28:00.000+05:30

Yeah, we all use google to "grep" for information. Well, recently I came to know about one option of grep which I never knew before.

grep -C[some number]

Check this out

Code:

root@bt> cat file
Apple
Bat
Cat
Dog
Elephant
Fan
Goat
Hat
Ink
Joker
King

root@bt> grep -n Fan file
6:Fan

root@bt> grep -n -C1 Fan file
5-Elephant
6:Fan
7-Goat

root@bt> grep -n -C2 Fan file
4-Dog
5-Elephant
6:Fan
7-Goat
8-Hat

As you can see,
-C1 will give you the one line before and after the match.
-C2 will give you two line before and after the match and so on.
-n option with grep will print the line number.
The -C[number] option will be handy if you want to see something before or after the line you are looking for.

Good Day!

"which" command wasn't working in Linux

2010-11-16T11:30:00.001+05:30

That was weird, or is that how it works?

I had this executable "db_linux" in "/usr/local/bin" and this was included in the env variable PATH. But there was no execute permission for this executable.And when I did a "which db_linux", it didn't show me anything. I was checking the file, the path everything was proper. The I thought fine lets execute it with absolute path. In the process I gave execute permission for the file and executed it. Later when I tried "which db_linux" again, it was showing. May be that is how it works.

BTW, I use Fedora Core 13 v 2.6.33.3

Code:

[root@ahamed bin]# ls -lrt
total 4
-rw-r--r--. 1 root root 63 Nov 16 16:33 db_linux

[root@ahamed bin]# which db_linux
/usr/bin/which: no db_linux in (/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:
/usr/loca/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin)

[root@ahamed bin]# chmod 744 db_linux
[root@ahamed bin]# ls -lrt
total 4
-rwxr--r--. 1 root root 63 Nov 16 16:33 db_linux

[root@ahamed bin]# which db_linux
/usr/local/bin/db_linux

Have a good day!

sed -i option

2010-11-15T04:51:00.000+05:30

We can use the -i option in sed to edit the file within the same command rather than directing it to another file and then renaming/moving it...

Code:

[ahamed@ahamed ~]$ cat textfile
# Check this line
The quick brown ajith jumps over the lazy dog

[ahamed@ahamed ~]$ sed -i '2 i \# Wow! I am the new guy' textfile

[ahamed@ahamed ~]$ cat textfile
# Check this line
# Wow! I am the new guy
The quick brown ajith jumps over the lazy dog

As you can see, after the -i option, the number is the line number to be inserted. The rest is the usual sed syntax. I'll break it up

sed - The command

i - For insertion

2 - Line Number

\#... - The line to be inserted

textfile - file being edited

If you don't use the option "-i", the file will not be edited. The changes will be displayed on the standard display.

Check this...

Code:

[ahamed@ahamed ~]$ cat textfile
# Check this line
# Wow! I am the new guy
The quick brown ajith jumps over the lazy dog

[ahamed@ahamed ~]$ sed '2 i # Wow! I am the NEXT new guy' textfile
# Check this line
# Wow! I am the NEXT new guy
# Wow! I am the new guy
The quick brown ajith jumps over the lazy dog

[ahamed@ahamed ~]$ cat textfile
# Check this line
# Wow! I am the new guy
The quick brown ajith jumps over the lazy dog

Good Day...

cold + fever + body pain+ head ache

2010-03-21T23:04:00.000+05:30

oh yeah... that's what will happen if you have an ice cream and coke right out of the swimming pool... damn!... thank god I have a good house owner... breakfast, lunch and dinner served... hee hee...

the cat which I caught yesterday... let it off today morning... I had a weird feeling that it didn't want to go... :D... anyway let it come back if it wants to...

Project Party

2010-03-20T23:56:00.000+05:30

Finally we had a good project party after a long time... some action... not like the previous ones...
Previous PP - before we all used to sit and look at each others face for sometime and then introduction - every time... man that was sick... and then we are supposed to dance... and the music... bloody hell!!!... it sounded like "baa baa black sheep"... hee hee... and then boozing... dinner... home... wow! what a party...

This time - as usual we all gathered around... introduction... and then we all fled to the ground... took cricket bat, football, volley ball etc all that we could get... then finally ended up playing cricket... it was fun... though I was the captain of the loosing team ;)... hee hee... but who cares... it was great...
Then some went for dinner and some for boozing... me and some of my friends joined the big guys for boozing... just had a beer thats all... and back for dinner... the non-veg was superb... specially the mutton... wow!... and then back home...

Hope we have some good project parties like this...

Cat fight... real cat fight...

2010-03-20T23:45:00.000+05:30

Couple of days ago, my cat came back with some serious injuries... I didn't know what happened... there are some street dogs in my neighbourhood, I thought those dogs might be the reason... (there is one dog among them which is loyal, we all use to feed it when it was chotu...)... but then later I came to know that, the fight is with another cat... a white cat with brown stripes... my house owner mentioned a cat roaming around... finally I caught the cat today... haa haa... Was watching IPL and my cat was outside the room... suddenly I heard some screeching noise... opened the door and alas! there it was fighting with mine... chintu(my cat) got into the room as soon as I opened it... the other one was trying to escape... locked it down till it was motionless... and then captured it with the waste basket and a brush... can't touch it you see ;) - I had enough from my own cat in the beginning... it's obviously someone else cat, there is some neck band... thought I'll keep it for the night and then leave it in the morning... poor cat, its so frightened... its not even 1 year old... I was so worried when my cat didn't come home for a couple of days...

Trying out mobile bloging...

2010-03-13T17:38:00.001+05:30

Its kinda cool... Technology... Didn't want to waste money on gprs, it was 140 INR per week for unlimited... They didn't have any other plans... But now theres one @99 per month for 300 mb... Oops i'm using airtel...
Time pass...
Hmmm... May be i should buy a qwerty phone...
Planning for a trip tomorrow...

Just another blog...

2009-04-10T08:03:00.000+05:30

my actual blog is password protected... only I can read it... kind of a personal diary... but this aint like that... let me see what I can put into this...