Recover svn repository

It is normal that svn db get crashed because of permission issue. The following steps help to fix it.

chown svnuser:svngroup /path/to/repos
find /path/to/repos -type d -print0 -exec chmod 2775 {} \;
find /path/to/repos -type f -print0 -exec chmod 0664 {} \;
svnadmin recover /path/to/repos

Vi Editor magics

Adding line number to a file with vi

open the file with vi editor

:%!nl

of-course there are other ways to do it with vi :)

Add empty line after every line with vi

:%s/\v(.*\n){1}/&\r

Remove white space at the beginning of a line with vi

:%le

Sorting lines with vi

:sort u

script to convert openssh keys to tectia and tectia to openssh


#!/bin/bash
# Arun N S
menu="
Make your choice:
1. Openssh key to Tectia format
2. Tectia key to Openssh format
3. Exit"
while :
do
printf "%s\n: " "$menu"
read choice
case $choice in
"1") echo "Converting Openssh key to Tectia format"
echo "Enter key Path(full path):"
while read INPUT
do
ssh-keygen -e -f ${INPUT} > ${INPUT}.tectia
echo "OpenSSH format key is saved as: ${INPUT}.tectia"
exit 0
done
break;;
"2") echo "Converting Tectia key to Openssh format";
echo "Enter File Path(full path):"
while read INPUT
do
ssh-keygen -i -f ${INPUT} > ${INPUT}.openssh
echo "OpenSSH format key is saved as: ${INPUT}.openssh"
exit 0
done
break;;
"3") echo "3. Exit"
echo " Good Bye"
break;;
*) echo "Wrong Choice"
;;
esac
done

./arun

configure NSD as slave for BIND

To configure name server deamon as slave for bind:

# useradd -c "NSD" -d /home/nsd -s /sbin/nologin -u 1005 nsd

Download and install the latest version of nsd

# ./configure --prefix=/home/nsd --enable-dnssec --enable-tsig --with-user=nsd
# make
# make install

Edit config: /home/nsd/etc/nsd/nsd.conf
>>>
server:
ip-address:
hide-version: yes
debug-mode: no
ip4-only: no
ip6-only: no
database: "/home/nsd/var/db/nsd/nsd.db"
identity: ""
logfile: "/var/log/nsd.log"
server-count: 1
tcp-count: 10
pidfile: "/home/nsd/var/db/nsd/nsd.pid"
port: 53
statistics: 3600
chroot: "/home/nsd/etc/nsd"
username: nsd
zonesdir: "/home/nsd/etc/nsd"
difffile: "/home/nsd/var/db/nsd/ixfr.db"
xfrdfile: "/home/nsd/var/db/nsd/xfrd.state"
xfrd-reload-timeout: 10

Add key and zone file details:

Start NSD with:
/home/nsd/sbin/nsdc start

to create zone files:
/home/nsd/sbin/nsdc patch

./arun

Changing subversion (svn) url

To change the svn url to another one:


$ svn switch --relocate file:///tmp/repos file:///tmp/newlocation .
or if it is with ssh
$ svn switch --relocate svn+ssh://username@svnurl/path/to/svn/ svn+ssh://new_username@new_svnurl/path/to/svn/

resetting mac os x password

To reset the password on MAC OS X,
- hold down apple+s key while booting the machine, this will take you to the single user mode
- Mount the file system using , # mount -uw /
- Enter the passwd command with username , #passwd
- reboot the machine

Anyway this will not reset the key chain password, to reset the key chain password:
1. Open Keychain Access, which is in the Utilities folder within the Applications folder.
2. From the Keychain Access menu, choose Preferences.
3. Click Reset My Keychain, which is under the General pane.
4. Authenticate with your account login password.
5. Quit Keychain Access.
6. Restart your computer.
ref : http://support.apple.com/kb/TS1544

./arun

auto responder with postfix/virtual

To configure autoreponder for some address with postfix.

Edit the postfix virtual configuration:
Add -
email_address recepient_lists, email_address@autoreply.nic.net.sa
eg: wordpress@example.com recepient1@example.com, wordpress@google.com@autoreply.example.com

Edit the transport configuration:
Add -
autoreply.domain.com autoreply:
eg: autoreply.example.com autoreply:

Create pipe for the transponder in master.cf

autoreply unix - n n - - pipe
flags= user=nobody argv=/usr/local/bin/autoreply $sender $recipient

Created autoreply script at /usr/local/bin/autoreply
eg:

/usr/sbin/sendmail -oi -t << EOF
From: nobody@example.com
To: $1
Subject: Auto Response from example.com
Content-Type: text/plain; charset=utf-8

This is an autoreponder email.
EOF


There is other better way to do it with procmail and other tools, depends on your mail server setup

Add SPF for validation to mail server

It is good to have spf implemented to make the recepient mail servers trust your entity.

Use the spf wizard http://old.openspf.org/wizard.html to generate the record and add it in your dns zone file.

./arun

get rid of apache@localhost in received email headers

There is a good change that the foreign email servers will drop if the sender email headers are not properly formatted.
Anyway if you get apache@localhost in Received header (with postfix/apache/php), you can change the php.ini, sendmail_path program to use sendmail.postfix instead of sendmail binary.

like : sendmail_path = /usr/sbin/sendmail.postfix -t -i -f

./arun

Hylafax/FaxMail with unicode encoding

It is pretty hard to get unicode works with fax ..
here are some scripts that i used to get the unicode done for incoming html/text faxes.

HTML
vi /etc/hylafax/faxmail/text/html
#!/bin/bash
cp -pf $1 /tmp/email.html
/usr/bin/lynx -dump -display_charset=utf-8 /tmp/email.html > /tmp/html_txt
/usr/bin/uniprint -font /etc/hylafax/faxmail/Cyberbit.ttf -in /tmp/html_txt -out /tmp/html_txt.uni
cat /tmp/html_txt.uni|/etc/hylafax/faxmail/filter.pl
rm /tmp/email.html
rm /tmp/html_txt
rm /tmp/html_txt.uni



plain text
vi /etc/hylafax/faxmail/text/plain
#!/bin/sh
/usr/bin/uniprint -font /etc/hylafax/faxmail/Cyberbit.ttf -in $1 -out /tmp/plain_txt
# echo " "
# echo "showpage"
cat /tmp/plain_txt | /etc/hylafax/faxmail/filter.pl
$rm /tmp/plain_txt

filter.pl
#!/usr/bin/perl
# Read from the standard input
@text=;
$size=@text;
# Count the number of "showpage"
$count=0;
for($i=0;$i<=$size;$i++){if($text[$i] =~ /showpage/){$count++;}}
# Discard the last line that contain "showpage"
$num=1;
for($i=0;$i<=$size;$i++){
if($text[$i] =~ /showpage/){
if($num!=$count){$num++;}
else{$text[$i]=~s/showpage//g;}
}
print $text[$i];
}

Cleanup mailman held messages

It will work usually with
$ cd /usr/lib/mailman
$ bin/discard /var/lib/mailman/data/heldmsg--*

If the list is too long
$ cd /var/lib/mailman
$ find data -name heldmsg--\* -print | xargs /usr/bin/discard

Browse internet from Mac with android

At last i managed to get browsing working through 3G connection in android (donut 1.6).

Steps:
- Enable root in android
- install android-wifi-tether (http://code.google.com/p/android-wifi-tether/)
- configure it either with bluetooth or wireless
- connect your laptop with the android using wireless or bluetooth
- there we go now you should be able to browse internet, if you have netfilter module properly working in wireless tether
- since my kernel doesnt have netfilter module, the natting was not working - I was able to resolve domains from my laptop , but was not able to get the data
- Installed proxoid, and started
- Configured my webbrowser to use proxoid as proxy, it works ... charm!!!!

./arun

get the root access back on android development phone ADP1

It seems that after upgrading ADP1 with 1.6 , the root access gone.

It can be recovered with adb tool:

Connect your mobile with the computer,

do adb to the phone
$adb shell
$mount -o remount,rw -t yaffs2 /dev/block/mtdblock3 /system
$cd /system/bin
$cat sh > su
$chmod 4755 su

Worked Great!!!

Ref: http://phandroid.com/2009/04/29/adp-15-initial-thoughts/

working with "screen"

Screen is a full-screen window manager that multiplexes a physical terminal between several processes (typically interactive shells).

to activate screen enter
$ screen

open a new session Ctrl+a+c

Scroll between sessions Ctrl+a+a

retain the sessions
$screen -R

check $man screen for much beautiful options

upgrade android to 1.5 cupcake

It was quiet trivial to update the android operating system to 1.5 manually,

The instructions for HTC ADP can be found at : http://developer.htc.com/adp.html

./arun

Tips to avoid spams from spamassassin

http://wiki.apache.org/spamassassin/AvoidingFpsForSenders

Fix for Postfix X-Authentication Warning

X-Authentication-Warning can appear on the mail header , when the user sending email is not trusted by the mail server. There is a chance that email are considered as spam because of this.

To fix it you can add the user to /etc/mail/trusted-users

If your system has forms that used to send email as apache user, you can add "apache" user to the trusted-users file.

Work with Android SDK on MAC OS X

It is wonderful experiance to work with android sdk and it is straight forward to get it working.
- Install Eclipse : http://www.eclipse.org/downloads/ (A Java or RCP version of Eclipse is recommended.)
- Download android SDK to a particular location
- Create a .bash_profile under your home directory (if not existing) with :
- Start eclipse and go to Help > Software Updates > Add Site
Enter the url : https://dl-ssl.google.com/android/eclipse/
and click finish. now you will be able to see the Developer tool listed
- Select and install the Developer tools from the same window.
- Restart eclipse.
- Connect your phone and test running your application.

./arun

Got HTC G1 Android working with Airtel Kerala

It was sad to just keep watching a phone without even switching it on, It took long for me to get HTC G1 development phone shopped to India, and once i got it after long waiting and excitement i was not able to get in to the home screen or basically cant do anyting with it.  G1 needs to have a data connection with the provider to start using, basically we need to login or register new account with google to start working with the phone. I was keep on trying with a BSNL connection with GPRS enabled to get the Android based G1 working. Anyway Atlast i got it working with Airtel connection (Kerala, Kollam) . Here is the APN configuration Information i used. Change the MNC value according to the location you are in.

Name : Airtel (it can be anything, just a name)
APN : airtelgprs.com
Proxy : 202.56.231.117
Port : 8080
Username : <Not Set>
Password : <Not Set>
Server : <Not Set>
MMSC : <Not Set>
MMS Proxy : <Not Set>
MMS Port : <Not Set>
MCC : 404
MNC : 95
APN Type: <Not Set>

That is it, once you have the APN settings entered correctly you will see data connection symbol on the top status bar.
It was hassle for me to get it working. So hope this help someone !!!

./arun