Psycho Tux

Accurate calculation of memory utilization in Linux

2011-03-21T16:25:00.001+05:30

Hi, We use ps aux | awk '{sum +=$4}; END {print sum}' to find the total memory utilization excluding the buffers and cache. This one manipulates the wrong data at some instances. No idea why  . So in addition to this we can adopt the below commands as wel..free -m | grep "+" | awk {'print $3/$4*100'}or more handyU=`free -m | grep "+" | awk {'print $3'}`;F=`free -m | grep "+" | awk {'print $4'}

Check remote UDP connectivity from Linux

2011-01-12T20:41:00.002+05:30

Hi there, You all know how to check TCP port connectivity from a Linux or UNIX machine to a remote machine using telnet as per th example below$ telnet 127.0.0.1 25 but we can't adopt TELNET to check UDP connectivity. Linux and most of the UNIXes come with a network layer utility called nc (abbreviation for netcat) which is very useful to check UDP connectivity and to explore a lot with both

Merge a number of files or file contents

2010-11-12T02:29:00.001+05:30

#!/bin/bash# Script to create a CSV formatted text with a file of a few lines having one entry per line.# This will merge the files line by linefor i in `cat test`; do echo $i > out/$i.out; done;paste -d, out/*

Problem with passwordless SSH as ROOT equivalent user

2010-10-17T11:41:00.004+05:30

Password less SSH using RSA/DSA public key helps a lot in automated file copying, scripts, cron, etc. but there found a trouble when a root equivalent user will try this mechanism. It wont work if you just copy/append the public key to remote server's ~/.ssh/authorized_keys. The wrong thing here is when you generate public key it will make one with username root instead of the real user's name

Backup of CRON list and jobs

2010-02-23T18:49:00.003+05:30

#!/bin/bashcd /opt/psycho/mkdir `hostname`_cronsOUT=`hostname`_crons> crons.txt> $OUT/cronlistfor i in `ls /var/spool/cron/`do grep $i /etc/passwd if [ $? = 0 ] then { crontab -u $i -l >> $OUT/$i.cron crontab -u $i -l | grep -v "^#" | sort | uniq | awk {'print $6'} >> crons.txt crontab -u $i -l | grep -v "^#" | sort | uniq | awk {'print $7'} >>

SSH Launcher

2010-02-09T02:15:00.001+05:30

#!/bin/bashecho Select the hostname to SSHHOSTS=/home/psychotux/scripts/conf/hosts.txtcat $HOSTS | cut -f3 -d'|'read hostecho Enter your username numberIP=`grep $host $HOSTS | cut -f2 -d'|'`ssh "$user"@$IPNote: /home/psychotux/scripts/conf/hosts.txt will be a file with values HOSTNAME and IP ADDRESS separated by "|"

SED-Replace multiple lines with a single line

2009-12-17T16:20:00.001+05:30

A useful option of sed command to replace multiple lines with a single line upon matching a given string. $ cat -n file.txtHello worldHello nobodynobodySomebodyanybody If you want to replace the lines 2 and 3 with another line "Hello everybody" the below command will help. $ sed '/nobody$/{N;s/Hello nobody\nnobody/Hello everybody/}' file.txt $ cat -n file.txt 1 hello world 2 Hello

SMTP authentication through TELNET

2009-12-17T16:07:00.002+05:30

It's common that we use TELNET to port 25 of Mail server to check the connectivity and to ensure the Mail flow.It's also possible to perform SMTP authentication in TELNET session$ telnet yourmailserver 25type “HELO”, hit Enter.AUTH LOGINNow you have to enter your email ID and then your password encoded in BASE64.For converting your email and password to Base64 use the conversion tools at WebPan

echo colourfully

2009-12-17T15:58:00.000+05:30

# for i in `cat num.txt`; do echo -en '\E[3'$i'm'"\033[1mPsycho Tux\033[0m " ; done;# for i in `cat num.txt`; do echo -en '\E[47;3'$i'm'"\033[1mPsycho Tux\033[0m " ; done; # cat num.txt1234567890

Block direct SSH to root, but not to root equivalent

2009-12-17T15:54:00.003+05:30

The PermitRootLogin no option of /etc/ssh/sshd_config will block all the users with UID 0. Below is an option to overcome this.# vi /etc/ssh/sshd_config###PermitRootLogin noAllowUsers newuser guest psychotux hariDenyUsers root # /etc/init.d/sshd restart Here users listed along with AllowUsers can be normal user or root equivalent.

Hardware clock failure in ISA system

2009-12-10T13:05:00.006+05:30

In ISA systems /sbin/hwclock will fail to fetch the Hardware clock and will throw an error similar to below.# hwclockselect() to /dev/rtc to wait for clock tick timed out# hwclock --showselect() to /dev/rtc to wait for clock tick timed out But the --directisa option of hwclock will work here.# /sbin/hwclock --directisa So as a permanent solution we can rename the existing binary /sbin/hwclock

Basic Linux Configuration backup

2009-04-27T19:24:00.001+05:30

#!/bin/bashDATE=`date +%d%m%y`BKP=~/`hostname`.BACKUPS_$DATE/bin/mkdir -p $BKP/sbin/ifconfig > $BKP/ifconfig/sbin/route -n > $BKP/route/sbin/runlevel > $BKP/runlevel/sbin/chkconfig --list | grep 3:on > $BKP/chkconfig_init_3/sbin/chkconfig --list | grep 5:on > $BKP/chkconfig_init_5/bin/hostname > $BKP/hostnamelsmod > $BKP/lsmodcat /etc/hosts > $BKP/etc_hostscat /etc/resolv.conf > $BKP/etc_resolv

Script to find normal users above UID 500

2009-03-08T22:01:00.000+05:30

Script to find normal users above UID 500 and their Shell History. This works in Linux. Other NIXes may require modification. #!/bin/bashUSERS=`grep ":5*:*:" /etc/passwd | grep "/bin/bash" | awk -F: '{print $1}'`HOME=`grep ":5*:*:" /etc/passwd | grep "/bin/bash" | awk -F: '{print $6}'`for i in $USERS do egrep -i "reboot|init|shutdown|halt|poweroff" `grep $i: /etc/passwd |

Ever alive SSH session

2009-03-01T03:17:00.006+05:30

If you are facing Session timeout issue whenever you are leaving an open session idle for some time you can make use of TCP Keepalive option in putty. 1. Open Putty2. Go to Connection->Seconds between keepalives(0 to turn off). Give a keepalive value here in seconds, preferably 120 or above. Advanced1. If you are using portaputty you can set it in config file .\putty\sessions\Default%20Settings.

VSFTPD-chrooted user with limited directory access

2009-02-10T13:41:00.003+05:30

Create a user with home directory /foo. Otherwise we can create a normal user and then edit /etc/passwd to change the home directory (useradd hari -d /foo). Here we chose the latter option since it's a sensible directory and we don't wnat to take risk by putting .bash files. # useradd hari# grep hari /etc/passwdhari:x:796:796::/home/hari:/bin/bashNow change the home directory to /foo# vi /etc/

Restricting su Access to System and Shared Accounts

2009-01-21T22:40:00.003+05:30

This chapter shows how to restrict people from su-ing to system and shared accounts even if they know the passwords.Example for Restricting su Access to rootCreate a new group for each set of users that are allowed to su to the root# groupadd rootmembersAdd all users who are allowed to su to the root account to the new member groups created above.The following requirement will be configured:-

Lock user account on frequent login failures

2009-01-21T22:27:00.001+05:30

Add the following two lines highlighted in blue to the /etc/pam.d/system-auth file as shown below:auth required pam_env.soauth required pam_tally.so onerr=fail per_user deny=3 resetauth required pam_access.soauth sufficient pam_unix.so likeauth nullok try_first_passauth requisite pam_succeed_if.so uid >= 500 quietauth required pam_deny.soaccount required pam_unix.soaccount required

Enforce stronger password in Linux

2009-01-21T22:20:00.002+05:30

The pam_cracklib module checks the password against dictionary words and other constraints.E.g. if you define password length minlen=10, then you will get 1 credit for e.g. using a single digit number in your password if you defined dredit=1. This means that pam_cracklib will accept a password of the length of minlen-credit. If you don't use a digit number, then the minimum length of the password

The best putty package available

2008-12-24T09:33:00.011+05:30

Bored of Black screened Task bar filling putty? Issues with porting Saved sessions from machine to machine? Do you like tabbed SSH sessions? Start using portaputty instead of normal putty and link it with puttycm. Puttycm supports sessions to be saved in its own Database files. You can use the Putty sessions you have saved already right inside putty. You can have any number of databases

screen for Remote assistance and chat

2008-12-10T18:04:00.004+05:30

screen is a UNIX utility for giving remote assistance/administration. Suppose an unskilled colleague of your own is struggling with a server at some remote location with no idea of troubleshooting a problem. If you are able to solve that with keeping your colleague to watch how you are sorting out the issues you can use screen. First of all ask your colleague for the username which he used to

Run X11 programs after SSH and switch to another user

2008-12-08T00:29:00.003+05:30

This issue arises when you are logging in as root and trying to launch some X11 programs after doing a switch to user oracle.One solution is to login directly as the user as which you want to run thos X11 programs. One more workaround is there.Here you can login as a different user. Thereafter run the below command xauth list | grep "`hostname`/"| grep `echo $DISPLAY | cut -f2 -d: | cut -f1

BASH script to delete older files

2008-11-25T15:26:00.001+05:30

# BASH Script to find files having Modification time older than 7 days and to remove.# A provisional confirmation before deletiion has been included# System files starting with "." in their names are excluded from deletion# And exclusive files that are specifies in the exclusion list are prevented from being deleted#!/bin/bashDIR=/home/hariLIST=/home/hari/DELETE_LISTEXCLUSIONS=/home/hari/

Install Linux from a remote machine

2008-11-22T13:26:00.020+05:30

This comes into picture when one Admin doesn't have physical access to a system in which Linux needs to be installed. Here we need help from one person who is having physical access to that remote machine to get it booted from bootable media and to type the command shown below command at boot prompt. Now anaconda will start to run and will pause at a particular moment showing the below message

How to disable a specific command(s) for a certain user.

2008-09-22T20:41:00.004+05:30

Please follow the below steps to disable a specific command(s) for a certain user.# su - hari$ which rm (Here rm command as an example)$ mkdir ~/bin$ ln -s /bin/* ~/bin/ (/bin is the PATH for rm)$ rm -rf ~/bin/rmTake the output of $PATH for this user$ echo $PATH > MyPATH.txt Edit this file and replace /bin with ~/binLogin as root$ su -# cat /home/hari/MyPATH.txt >> /home/hari/.bashrc

Disable Media Check for cdrom

2008-07-28T13:15:00.000+05:30

Grub.confdma=off apci=off apm=off/etc/hdparm.confcommand_line {hdparm -d1 /dev/cdrom}command_line {hdparm -d1 /dev/cdrom1}sysctl.confdev.cdrom.check_media = 0

MySQL Compilation

2008-07-28T12:57:00.000+05:30

# groupadd mysql# useradd -g mysql -c "MySQL Server" mysql# tar zxf mysql-5.0.45.tar.gz# cd /usr/local/src/ mysql-5.0.45# .chown -R root.root *# ./configure \--prefix=/usr/local/mysql \--localstatedir=/usr/local/mysql/data \--disable-maintainer-mode \--with-mysqld-user=mysql \--with-unix-socket-path=/tmp/mysql.sock \--without-comment \--without-debug \# groupadd mysql# useradd -g mysql -c "MySQL

Open multiple tabs with Gnome-Tminal

2008-07-28T12:55:00.001+05:30

gnome-terminal --geometry=125x75 --tab -e "ssh192.168.0.67 -l myuser" --tab -e "ssh192.168.0.45 -l root" --tab -e "ssh 192.168.0.88 -lroot" --tab -e "ssh 192.168.1.145 -l root -p 22999"

Set date from CLI

2008-07-28T12:54:00.000+05:30

# date 030710532008dateFri Mar 7 10:53:01 IST 2008

Bugzilla installation

2008-03-11T11:35:00.003+05:30

Reference bugzilla.orgDownload the latest Stable Release# cd /usr/local/src# wget http://ftp.mozilla.org/pub/mozilla.org/webtools/bugzilla-3.0.3.tar.gz# tar xzf bugzilla-3.0.3.tar.gz# cd bugzilla-3.0.3 First,run the checksetup.pl script to check for any dependant packages that need to be installed# ./checksetup.pl --check-modules NOTE: You must run any commands listed below as root.************

Log Server using Syslog-NG

2008-03-04T16:49:00.005+05:30

Server - RHEL 5Stop Syslog and turn it off through Run Levels# service syslog stop# chkconfig syslog offDownload syslog-ng# cd /usr/local/src# wget http://www.balabit.com/downloads/files/eventlog/0.2/eventlog-0.2.5.tar.gz# tar xzf eventlog-0.2.5.tar.gz# cd eventlog-0.2.5# ./configure --prefix=/usr/local/eventlog# make # make install# cd /usr/local/src# wget http://www.balabit.com/downloads/files/

Log Server using Syslog

2008-03-03T18:11:00.002+05:30

Log Server SetupAllow remote machines to Log# vi /etc/sysconfig/syslog Replaced SYSLOGD_OPTIONS="-m 0" with SYSLOGD_OPTIONS="-rm 0"Setup Log Rotation Policy # vi /etc/logrotate.conf daily # keep 7 days worth of backlogs rotate 7 # create new (empty) log files after rotating old ones create # uncomment this if you want your log files compressed compress # RPM packages drop log

Apache SSL Certificate Creation

2008-03-03T17:38:00.006+05:30

# cd /usr/local/apache# mkdir cert# cd cert1. Generate your own Certificate Authority (CA) # openssl genrsa -out ca.key 4096 # openssl req -new -x509 -days 365 -key ca.key -out ca.crt2.Generate a server key and request for signing (csr) # openssl genrsa -out server.key 4096 # openssl req -new -key server.key -out server.csr3.Sign the certificate signing request (csr) with the self-created

Firewall Failover with CARP,PF and PFSYNC in OpenBSD 4.2 under VMWare ESX3

2008-02-11T12:20:00.001+05:30

CARP Setup----------Reference http://www.openbsd.org/faq/pf/carp.htmlCARP Master-----------# cat /etc/hostname.pcn1# ifconfig carp0 create# ifconfig pcn1 up# ifconfig carp0 vhid 2 pass mysecretpassword carpdev pcn1 advbase 1 advskew 1 state master PUB.LIC.IPA.DDR netmask 255.255.255.0 broadcast PUB.LIC.IPA.DDR# echo "inet PUB.LIC.IPA.DDR 255.255.255.0 PUB.LIC.IPA.DDR vhid 2 pass mysecretpassword

Squid dead but subsys locked

2008-01-16T12:19:00.000+05:30

# /etc/init.d/squid status squid dead but subsys locked# df -h# rm -rf /var/run/squid.pid# rm -rf /var/lock/subsys/squid# tail -f /var/log/messages# tail -f /var/log/squid/cache.log# /etc/init.d/squid start2007/12/28 09:57:16| Starting Squid Cache version 2.5.STABLE6 for i386-redhat-linux-gnu...2007/12/28 09:57:16| Process ID 267012007/12/28 09:57:16| With 1024 file descriptors available2007/12/

Multiple Network connectivity issue in OpenBSD within VMWware

2008-01-16T12:14:00.001+05:30

Only the first NIC of each Virtual machine will work .None of the rest won't.So added a Virtual Network Resource for that Virtual machine in VMWare Control PanelBut it didn't work this time.Only the first NIC will work So logged into the VMWare Virtual Console and checked the Virtual Switches and VLAN SettingsIt was clear that there is a Virtual Switch named "vSwitch0" And this switch contains

Auto Responder plugin in SquirrelMail

2008-01-16T12:01:00.001+05:30

1.Download the compatibility plugin and Local Auto Responder plugin from http://squirrelmail.org2.Extract it to the Squirrelmail - plugins directory # pwd /var/www/html/squirrelmail/plugins # tar xzf compatibility-2.0.9-1.0.tar.gz # cd compatibility3.Patch it to your squirrelmail version # patch -p0 < patches/compatibility_patch-1.4.11.diff patching file ../../functions/strings.php4.

Database Clustering with Sequoia

2008-01-16T11:41:00.001+05:30

Sequoia Installation in RHEL 5 with MyOsotis

Swami Vivekananda

2007-12-29T09:31:00.000+05:30

When I Asked God for Brain & BrownHe Gave Me Puzzles in Life to SolveWhen I Asked God for HappinessHe Showed Me Some Unhappy PeopleWhen I Asked God for WealthHe Showed Me How to Work HardWhen I Asked God for FavorsHe Showed Me Opportunities to Work HardWhen I Asked God for PeaceHe Showed Me How to Help OthersGod Gave Me Nothing I WantedHe Gave Me Everything I Needed All that is real in me is

Tunnel TCP connections over ICMP echo-reply/echo-request

2007-12-20T17:39:00.000+05:30

You can tunnel TCP connections over ICMP echo-reply/echo-request packets.You need a PingTunnel Server(called proxy) and a client both with the application PingTunnel installed on it . It is useful behind firewall.Follow this URL. Its all therePingTunnel

SecureServer.sh

2007-12-19T16:28:00.000+05:30

#!/bin/bash########### SysCTL Hardening ########## Disable ICMP routing redirects. Otherwise, your system could have its routing table misadjusted by an attacker sysctl -w net.ipv4.conf.all.accept_redirects=0#sysctl -w net.ipv6.conf.all.accept_redirects=0sysctl -w net.ipv4.conf.all.send_redirects=0#sysctl -w net.ipv6.conf.all.send_redirects=0#Disable IP source routing. The only use of IP source

Limit number of Shell logins by a USER or GROUP

2007-12-18T20:03:00.000+05:30

To limit multiple Shell login by the same user on a Linux box you have to set a maximum number of logins in /etc/security/limits.conf for a user or a group.For example:# groupadd salesgroup# useradd -G salesgroup salesman1# useradd -G salesgroup salesmanager# echo "@salesgroup - maxlogins 10" >> /etc/security/limits.conf# echo "salesman1 - maxlogins 5" >> /etc/security/limits.confHere the

Starting httpd: execvp: No such file or directory [FAILED]

2007-12-10T18:33:00.000+05:30

I downloaded the source for the latest Apache HTTP and installed it 1. ./configure --enable-so 2. make3. make install When I ran# /usr/local/apache2/bin/apachectl startit was fine. But it began to show errors when I tried to run # /etc/init.d/httpd start My /etc/init.d/httpd is as follows . /etc/rc.d/init.d/functions case "$1" in start) echo -n "Starting httpd: "

How to Disable Alt+Ctrl+Bksp and Ctrl+Alt+Function Keys

2007-12-07T17:49:00.000+05:30

System administrators should be aware that now there is the ability to turn off switching to text mode virtual terminals via CTL-ALT-FunctionKey. This can come in handy when locking down a system (such when a Linux box is used as a kiosk) when used in conjunction with disabling CTL-ALT-BKSP (forceful kill of the X server). To do this, edit your /etc/X11/XF86Config or /etc/X11/xorg.conf and add

Tunneling TCP Services over HTTP(S)

2007-11-22T10:11:00.001+05:30

HTTP Tunnel Definition HTTP Tunneling is a technique by which communications performed using various networkprotocols are encapsulated using the HTTP protocol, the network protocols in question usually belonging to the TCP/IP family of protocols. The HTTP protocol therefore acts as a wrapper for a covert channel that the network protocol being tunneled uses to communicate.The HTTP stream with

Bash Script for FTP

2007-11-16T17:12:00.000+05:30

#!/bin/bashUSER=myusernamePASS=mypasswdFTPSERVER=192.168.0.Xftp -i -n $FTPSERVER << EOFuser $USER $PASS mkdir testcd testput myfilebye>>But FTP will allow transfer of files only,not the directory tree.If you want to transfer the Directory structure through FTP you can use LFTP or similar FTP clients. A variety of GUI Based clients are availableLFTPlftp has builtin mirror which can download or

How to disable directory browsing in Apache

2007-11-16T16:50:00.000+05:30

One of the "must do's" on setting a secure apache webserver environment is to disable directory browsing. As a default Apache will be compiled with this option enabled, but its always a good idea to get rid of this setting unless its really necessary. If you are on an RPM installation of Apache you will find the apache configuration file probably here:/etc/httpd/conf/httpd.confIf you are using

Reboot Linux box after a kernel panic

2007-11-16T16:28:00.000+05:30

If you want the server to get rebooted automatically after kernel hit by a pain error message, try adding panic=N to /etc/sysctl.conf file.It specify kernel behavior on panic. By default, the kernel will not reboot after a panic, but this option will cause a kernel reboot after N seconds. For example following boot parameter will force to reboot Linux after 10 seconds.Open /etc/sysctl.conf file#

Adding Extra Swap Space

2007-11-16T16:14:00.001+05:30

There are situations where we have to expand the SWAP space after installation. For example, suppose you are upgrading RAM 512MB to 1 GB MB, but there is only 1 GB of swap space available which was created during installation. It might be an advantage to increase the amount of swap space to Double the RAM(2 GB) as per the UNIX/Linux guidance and will help you to perform memory eaters.You have two

PHP and Pear MDB2 Installation

2007-11-16T15:27:00.001+05:30

Installation of Pear MDB2 (2.4.1) with Apache-2.2.6 PHP-5.2.3(with MySQL and MySQLI)Backed up Existing PHP[root@hareesh ~]# mv /usr/local/lib/php /usr/local/lib/php.bak[root@hareesh ~]# mv /usr/local/bin/php /usr/local/bin/php.bak[root@hareesh ~]# mv /usr/local/include/php /usr/local/include/php.bakInstalled PHP-5.2.3 with MySQL and MySQLI Support[root@hareesh lib]# cd /usr/local/src/[root@

Cannot execute [Argument list too long]

2007-11-13T09:44:00.000+05:30

Tried to remove some files like log files with /bin/rm -rf all at once, and you get thisError message# rm -rf /var/log/mail/*.old.logbash: /bin/rm: /bin/rm: cannot execute [Argument list too long]So, rm utility complains that the system-wide ARG_MAX value that is used to setup an input buffer size to process the entire list will overflow. Good security measure, but, doesn't help you out with the

Auto Logout of Inactive Users

2007-11-10T12:28:00.001+05:30

How to force automatic logouts of users who forget to log out in case of inactivity detected ? BASH have a TMOUT variable.We can set the TIMEOUT value here for sessions. Add the TMOUT variable to your /etc/bashrc file:# vi /etc/bashrcSet TMOUT to 300 seconds (5 minuets):TMOUT=300This will automatically logout users after 300 seconds of inactivity. This hack will only work with run level 2, 3

Simple Server Monitor

2007-11-09T19:22:00.001+05:30

#!/bin/bash# BASH Script to monitor Server uptime,Servies,Memory Usage,Disk Usage,Load Average,Last Login and Reboot Details and Take backup of configuration files.DATE=`date +%d.%m.%Y`TIME=`date +%H.%M.%S`ADMIN=hareeshvv@gmail.com ## Mail ID of AdminADMIN1=hareeshvaliyaveettil@gmail.com ## Mail ID of AdminFILES=(/etc/hosts /usr/local/apache/conf/httpd.conf /etc/php.ini /var/lib/pgsql/data/

Installation of PHP-Screw 1.5 with Apache 2.2.6 and PHP-5.2.3

2007-11-09T18:53:00.002+05:30

Apache 2.2.6 Installation[root@myserver src]# pwd/usr/local/src[root@myserver src]# cd httpd-2.2.6[root@myserver httpd-2.2.6]#[root@myserver httpd-2.2.6]# ./configure --enable-so --prefix=/usr/local/apache2[root@myserver httpd-2.2.6]# make[root@myserver httpd-2.2.6]# make installPHP-5.2.3 installation[root@myserver src]# pwd/usr/local/src[root@myserver src]# cd php-5.2.3[root@myserver php-5.2.3]#

postfix/smtp connect to gmail.com[64.233.171.83]: Connection timed out (port 25) server dropped connection without sending the initial SMTP greeting

2007-11-07T11:54:00.000+05:30

Postfix has been configured fine. The mail is working in the local Domain - mydomain.com But when I try to send mails to outer domains,it produces the following "TIMEOUT" errors in /var/log/mail/infoNov 5 23:02:43 mydomain postfix/pickup[30923]: 419941C678: uid=555 from=Nov 5 23:02:43 mydomain postfix/cleanup[31536]: 419941C678: message-id=<20071106050243.419941C678@mydomain.com>Nov 5 23:02:

QMAIL port 25 and 110 are closed

2007-11-05T10:47:00.001+05:30

Qmail installation went fine .But I was unable to connect to port 25 and 110.They were in closed state.When I tried to connect with telnet I got the “Connection refused” message. # qmailctl stat/service/qmail-send: up (pid 2219) 37 seconds/service/qmail-send/log: up (pid 2311) 37 seconds/service/qmail-smtpd: up (pid 2917) 1 seconds/service/qmail-smtpd/log: up (pid 2723) 37 seconds/service/

BASH Script to Generate files from existing ones with a partial change in filename

2007-11-03T17:36:00.000+05:30

#!/bin/bash# BASH Script to generate $EXTENSION files like FILE_fr.$EXTENSION,FILE_sp.$EXTENSION from existing FILE_$SEARCHSTRING.$EXTENSION without causing any kind of overwrite.DIR=/tmp/htmlEXTENSION=extensionSEARCHSTRING=encd $DIR > /dev/null 2> /dev/nullcount=`find *$SEARCHSTRING.$EXTENSION | wc -l`n=1echo $count \"*$SEARCHSTRING.$EXTENSION\" files foundwhile [ $n -le $count ] do {

A Simple Service Monitor

2007-11-03T17:35:00.001+05:30

#!/bin/bash# Check the Service Status of Server and send notification mail if anyone is DOWN.Server=192.168.0.35 ## IP of the remote Server to be monitoredADMIN=hareeshvv@gmail.com ## Mail ID of AdminSubject=Server-StatusDATE=`date +%d.%m.%Y`TIME=`date +%H.%M.%S`mkdir /tmp/$DATE.$TIMEcd /tmp/$DATE.$TIMEservices=(http https mysql smtp pop imap imaps ssh) ## List of services to be checkedWatch ()

How to Create Custom Hot key to Launch Applications in GNOME

2007-11-03T16:35:00.002+05:30

1. Open Applications -> System -> Configuration Editor from the GUI OROpen a terminal, type gconf-editor2. Go to "apps" -> "metacity" -> "keybinding_commands"3. Double-click on an unused element e.g. "command_10"4. Type in the name of the application you want to launch, for e.g. "firefox" or "gnome-terminal"5. Then go to "apps" -> "metacity" -> "global_keybindings"6. Double-click

Simple Disk and Memory Monitor

2007-11-03T12:26:00.001+05:30

#!/bin/sh# Shell script to monitor the disk space,Memory,SWAP Usage and send an email to $ADMIN, if the free avilable percentage of space is >= $ALERT ADMIN="hareeshvv@gmail.com"ADMIN1="admin1@mycompany.com"ADMIN2="admin2@mycompany.com"# Alert Level Percentage of Disk Usage . Default is 90%ALERT=90df -h | grep -vE '^Filesystem|tmpfs|cdrom' | awk '{ print $5 " " $1 }' | while read output;do used=

ConCatPASSWD.sh

2007-10-17T15:07:00.002+05:30

#!/bin/bash# Concatenate two passwords files. The resulting will contain entries of the first file with UID < 500 and that of second with UID > 500DATE=`date +%d.%m.%Y`TIME=`date +%H.%M.%S`echo Name of File 1read f1echo Name of File 2read f2echo Name for New fileread newfilemv $newfile $newfile.bak.$DATE.$TIME ## Manipulate first filecount=`cat $f1 | cut -f3 -d : | sort -n | wc -l` h=1while [ "$

ChangeGID.sh

2007-10-17T15:06:00.001+05:30

#!/bin/bash# Change the GID of a Group and make it effective for all the members in /etc/passwdpwfile=/etc/passwdgrpfile=/etc/groupDATE=`date +%d.%b.%Y`TIME=`date +%H.%M.%S`echo Creating backups $pwfile.$DATE.$TIME and $grpfile.$DATE.$TIMEcat $pwfile > $pwfile.$DATE.$TIMEcat $grpfile > $grpfile.$DATE.$TIMEecho Enter group nameread gnamecgid=`grep $gname $grpfile | cut -f3 -d:`username_s=`cat $

RUNCMDS.sh

2007-10-17T15:05:00.000+05:30

#!/bin/bash## BASH Script to Run any System command ####### Script should be initialized as ./script.sh arg1 arg2 arg3,....## echo "Commands with spaces should be supplied as \`COMMAND OPTIONS\`."## echo "For example "./runcdms.sh \`mkdir test\` \`chmod 777 test\`""for i in `$*`do #sudo - u root $i ## You can sudo if you are not root $idone

PING.sh

2007-10-17T15:04:00.000+05:30

#!/usr/bin/env bash## Ping all machines in a NetworkPING="$(which ping) -c 1 -W 1"echo "Enter Subnet(eg:192.168.0)"read Subnetecho "Do you want to PING the entire network or a RANGE of IPs ? Enter your choice"echo 1. Ping Entire Networkecho 2. Ping a RANGEread choiceif [ $choice = 1 ]; then { echo Pinging..... for((i=1;i<255;i++)); do ${PING} ${Subnet}.${i} > /dev/null 2> /dev/null if [ $

Starting X11 VNC in Linux

2007-08-23T18:06:00.000+05:30

Create vnc passwdx11vnc -storepasswdUse authentication while connecting x11vnc -rfbauth ~/.vnc/passwdKeep the VNC Session after each login and logout x11vnc -foreverDon't use shm of X if you have problems in display x11vnc -noshmSo the final command is x11vnc -noshm -forever -rfbauth ~/.vnc/passwd

Disabling Caps lock in Linux

2007-07-23T18:35:00.001+05:30

Master Your Linux Keyboard (And Fix Caps Lock Forever)Exorcising Caps LockWant to get rid of the evil caps lock key without mutilating your keyboard? Want to give those silly Windows keys useful jobs, or put all those extra multi-media keys to work? Want to become a powerhouse keyboarding commando? Then come along and join the fun, because Linux has all kinds of good tools for taming wayward

Remove LAME Logging and Version Exposure in BIND

2007-07-23T10:36:00.000+05:30

Got lame server errors? Are you exposing your bind version?Are lame-server errors filling up your logs? Are you letting bind send its version out to potential attackers? You can fix these issues with some simple changes.Simple Bind Configuration ChangesLame Server ErrorsIf you look in your message logs, you may see an error about a "lame server". A lame server is when the NS record for a domain

Display Problem in SUSE 10 with Matrox G400 Graphics Card and USB Mouse

2007-07-14T17:38:00.000+05:30

After installing SUSE 10.0 Display was not workingGraphics Card : Matrox G 400Monitor : Samsung SyncMaster 594 MG1. I logged into runlevel 3 and tried to fire up X11systemp5:~ # startxxauth: creating new authority file /root/.serverauth.8991X Window System Version 6.9.0Release Date: 21 December 2005X Protocol Version 11, Revision 0, Release 6.9Build Operating System: SuSE Linux [ELF]

Installation of JBoss on Suse 10 with IBM p5

2007-07-10T13:01:00.000+05:30

SuSe 10.2 on IBM P 520 with Apache2 ,Tomcat 6 ,JSDK 1.4.2 and Jboss 4.0.5.GAReference for known problemshttp://entropy.brneurosci.org/linuxsetup82.html Installed SUSE 10 Patitiions /dev/sda1 is of type PReP.And its size is 10 MB/dev/sda5 9.9G 1003M 8.4G 11% //dev/sda2 99M 18M 77M 19% /boot/dev/sda8 26G 345M 25G 2% /home/dev/sda6

Linux Operating System

2007-06-30T16:51:00.000+05:30

Linux Newbie Administrator Guide (LNAG)LINUX NEWBIE ADMINISTRATOR GUIDEver. 0.201 2004-07-22 by Stan, Peter and Marie KlimasThe latest version of this guide is available at http://linux-newbie.sunsite.dk.Copyright (c) <1999-2004> by Peter and Stan Klimas. Your feedback, comments, corrections, and improvements are appreciated. Send them to linux_nag@canada.com This material may be distributed only