Thursday, October 18, 2007

creating global rules in openwebmail

open Openwebmail cgi-bin folder (/var/www/cgi-bin/openwebmail)/etc/ and add the rule. Local user rules exist in ~user/.openwebmail/webmail/

Wednesday, October 10, 2007

amavis - To allow only password protected archives

Add these two rules somewhere towards the end
of the list in $banned_filename_re:

# allow if it is or contains any undecipherable components:
[ qr'^UNDECIPHERABLE$'=> 0 ],

qr'^\.(zip|tar)$', # block zip and tar (unless password protected)

Encrypting file in Linux

To encrypt single file, use command gpg

$ gpg -c filename

Enter Passphrase:
Repeat passphrase:

File becomes filename.gpg

To Decrypt

gpg filename.gpg
gpg: CAST5 encrypted data
gpg: Enter passphrase

original file is extracted out of the encrypted file

Friday, September 28, 2007

pwck, grpck

pwck for checking correctness of passwd file

grpck for checking correctness of group file

Thursday, September 27, 2007

copy files by date

scp files created in DIR_NAME on a particular date to TARGET_COMPUTER

find DIR_NAME -mtime "{DATE}" -exec scp {} TARGET_COMPUTER \;

process states

use top command to know the status of a process

state of the process:
T-stopped or traced,
D-uniterruptable sleep,

driver module for NIC card

Get full details of driver module for NIC card using "ethtool eth#

eth# could be eth0 or eth1 or eth2 ...

Enhanced mem support upto 64 GB

PAE is an Intel-provided memory address extension that enables support of
greater than 4 GB of physical memory upto 64 GB for most 32-bit (IA-32) Intel Pentium
Pro and later platforms.

Details at

To execute a PAE-enabled kernel add
to bootloader file grub.conf and reboot.

Get day of a date

# date -d 2007-09-26 +%A

Wednesday, September 26, 2007

lshw command RHEL4

lshw" is a small tool to extract detailed information on the hardware configuration of the machine

rhel4 x86_64 'thru' apt-get

apt-get install for RHEL4 64 bit architecture

#rpm -ivh

#vi /etc/apt/sources.list.d/os.list (add following mirrors)
repomd redhat/el4/en/x86_64/dag/
repomd rpms/el4.x86_64/

#apt-get update
#apt-cache search pkg
#apt-get install pkg
#apt-get remove pkg

replace pkg by package name


php dom module rpm for RHEL4 is implemented thru php-xml rpm

Thursday, September 20, 2007

Welcome Linux fans

I am an Open source fan and would love to enrich my knowledge with others' and others with mine thru this platform Post anything related to Linux..