Usually, you do not need to setup an email server under Linux desktop operating system. Most GUI email clients (such as Thunderbird) supports Gmail POP3 and IMAP configurations. But, how do you send mail via the standard or /usr/bin/mail user agents or a shell script? Programs such as sendmail / postfix / exim can be configured as a gmail smarthost but they are largely overkill for this use.
Internet censorship in the People’s Republic of China is conducted under a wide variety of laws and administrative regulations. In accordance with these laws, more than sixty Internet regulations have been made by the People’s Republic of China (PRC) government, and censorship systems are vigorously implemented by provincial branches of state-owned ISPs, business companies, and organizations. So how do you find out if your website is blocked by the Great Firewall of China?
How do I access networked file system mounts such nfs via ftp servers under Linux / UNIX?
It happens all the time. Sooner or later, every organization may run out of qualified admin staff because of various issues. So how do you deal with fresh out of school admins or other helping people in your organization?
Reverse order files while sorting and play with mplayer multimedia player.
KDE 4 has been released. I’ve received couple of questions about installing KDE 4 under Ubuntu Linux 7.10. KDE 4 Packages are available for Ubuntu Linux version 7.10 (Gutsy) and from development Ubuntu Linux Hardy version. They install to /usr/lib/kde4 and can be installed alongside your existing KDE 3. However these packages are not compatible with KDE 4 beta packages. Following simple step will help you install KDE 4.
How do I install KDE 4 under Ubuntu Linux?
First you need to update Ubuntu package source file.
Step # 1: Update Source File
Open a terminal
Open /etc/apt/sources.list file using a text editor such as vi or gedit, enter:
$ sudo vi /etc/apt/sources.list
$ sudo gedit /etc/apt/sources.list
Append following line:
deb http://ppa.launchpad.net/kubuntu-members-kde4/ubuntu gutsy main
Close and save the file. Type the following command to update package list:
$ sudo apt-get update
GUI tool to update software source
Alternatively, you can use GUI tool by visiting System > Administration > Software Sources > Third Party Software > Add > Enter url ‘deb http://ppa.launchpad.net/kubuntu-members-kde4/ubuntu gutsy main‘ > Add Source > Update > Close
(Fig. 01: Update Software Source for KDE 4)
Step # 2: Install KDE 4 desktop
To install kde 4, enter:
$ sudo apt-get install kde4-core
You’ll get a warning when installing kde 4, just force to install the same without verification:
WARNING: The following packages cannot be authenticated!
Install these packages without verification [y/N]? y
Reading package lists... Done Building dependency tree Reading state information... Done The following extra packages will be installed: dbus-x11 dolphin-kde4 kappfinder-kde4 kde-icons-oxygen kde4libs-bin kdebase-bin-kde4 kdebase-data-kde4 kdebase-kde4 kdebase-runtime kdebase-runtime-bin-kde4 kdebase-runtime-data kdebase-runtime-data-common kdebase-workspace kdebase-workspace-bin kdebase-workspace-data kdelibs5 kdelibs5-data kdepasswd-kde4 kdepimlibs-data kdepimlibs5 kfind-kde4 klipper-kde4 konqueror-kde4 konqueror-nsplugins-kde4 konsole-kde4 ksysguard-kde4 ksysguardd-kde4 kwin-kde4 kwrite-kde4 libcapseo0 libcaptury0 libclucene0 libexiv2-0 libgpgme11 libkonq5 libkonq5-templates libphonon4 libplasma1 libpth20 libqimageblitz4 libraptor1 librasqal0 librdf0 libsoprano4 libstreamanalyzer0 libstreams0 libstrigiqtdbusclient0 systemsettings-kde4 Suggested packages: kdebase kde-i18n sword-frontend gpgsm Recommended packages: exiv2 raptor-utils redland-utils The following NEW packages will be installed: dbus-x11 dolphin-kde4 kappfinder-kde4 kde-icons-oxygen kde4-core kde4libs-bin kdebase-bin-kde4 kdebase-data-kde4 kdebase-kde4 kdebase-runtime kdebase-runtime-bin-kde4 kdebase-runtime-data kdebase-runtime-data-common kdebase-workspace kdebase-workspace-bin kdebase-workspace-data kdelibs5 kdelibs5-data kdepasswd-kde4 kdepimlibs-data kdepimlibs5 kfind-kde4 klipper-kde4 konqueror-kde4 konqueror-nsplugins-kde4 konsole-kde4 ksysguard-kde4 ksysguardd-kde4 kwin-kde4 kwrite-kde4 libcapseo0 libcaptury0 libclucene0 libexiv2-0 libgpgme11 libkonq5 libkonq5-templates libphonon4 libplasma1 libpth20 libqimageblitz4 libraptor1 librasqal0 librdf0 libsoprano4 libstreamanalyzer0 libstreams0 libstrigiqtdbusclient0 systemsettings-kde4 0 upgraded, 49 newly installed, 0 to remove and 2 not upgraded. Need to get 105MB of archives. After unpacking 204MB of additional disk space will be used. Do you want to continue [Y/n]? y WARNING: The following packages cannot be authenticated! libphonon4 libstreams0 libstreamanalyzer0 kdelibs5-data kde4libs-bin kdelibs5 libstrigiqtdbusclient0 libkonq5-templates libkonq5 dolphin-kde4 kappfinder-kde4 kdebase-data-kde4 kdebase-bin-kde4 kdepasswd-kde4 kfind-kde4 konqueror-nsplugins-kde4 konqueror-kde4 konsole-kde4 kwrite-kde4 kdebase-kde4 kdebase-workspace-data libplasma1 ksysguardd-kde4 ksysguard-kde4 kdebase-workspace-bin klipper-kde4 kwin-kde4 systemsettings-kde4 kdebase-workspace kdepimlibs-data kdepimlibs5 kde4-core... Install these packages without verification [y/N]? y Get:1 http://ppa.launchpad.net gutsy/main libphonon4 4:4.0.0-0ubuntu2~gutsy1~ppa1 [164kB] Get:2 http://archive.ubuntu.com gutsy-backports/universe kde-icons-oxygen 4:4.0.0-0ubuntu1~gutsy1 [45.4MB] Get:3 http://in.archive.ubuntu.com gutsy/main dbus-x11 1.1.1-3ubuntu4 [34.8kB] ................ ... ......... Setting up systemsettings-kde4 (4:4.0.0-0ubuntu7~gutsy1~ppa1) ... Setting up kdebase-workspace (4:4.0.0-0ubuntu7~gutsy1~ppa1) ... Setting up kde4-core (3.3~gutsy1~ppa1) ... Processing triggers for libc6 ... ldconfig deferred processing now taking place
Note: It may take some time to install kde 4. You also need to disable compiz 3d desktop effect support.
=> Kubuntu Project – Be Free with KDE 4.0
I already wrote about nohup command, which allows you to ignore HUP (hangup) signal and keep running the command after user logged out. You can accomplish the same behavior using screen or disown command.
setsid is another program that runs a program in a new session. For example run a script called ~/scripts/mirror.site:
You can also pass argument to command or script:
setsid /usr/bin/beep-media-player '/nas/mp3/xyz.mp3'
Please note that setsid included in miscellaneous system utilities package called util-linux under Debian / Ubuntu Linux.
I use ps command to find out all running process on my Linux and Unix system. The ps command shows information about a selection of the active processes on shell. You may also pipe out ps command output through grep command to pick up desired output.
By hiding out DNS server version number you can improve server security. fpdns is a program that remotely determines DNS server versions. It does this by sending a series of borderline DNS queries which are compared against a table of responses and server versions. (just like nmap commandâ€™s remote OS detection facility).
A nameserver basically responds to a query. Interoperability is an obvious requirement here. The standard protocol behavior of different DNS implementations is expected to be the same.
Debian / Ubuntu user, enter the following command:
$ sudo apt-get install fpdns
FreeBSD user, either use ports or binary package:
$ pkg_add -v -r fpdns
Alternatively grab source code from official web site.
Howto remotely determine DNS server version
To determine DNS server version for domain nixcraft.com, enter:
$ fpdns -D nixcraft.com
fingerprint (nixcraft.com, 18.104.22.168): bboy MyDNS fingerprint (nixcraft.com, 22.214.171.124): bboy MyDNS
You can easily find out if recursion enabled or not:
$ fpdns ns1.vnsl.com.
fingerprint (ns1.vnsl.com., 126.96.36.199): ISC BIND 9.2.3rc1 -- 9.4.0a0 [recursion enabled]
To read list of servers from key board, enter:
$ fpdns -
ns2.vnsl.com fingerprint (ns2.vnsl.com, 188.8.131.52): ISC BIND 9.2.3rc1 -- 9.4.0a0 [recursion enabled] ns1.softlayer.com fingerprint (ns1.softlayer.com, 184.108.40.206): ISC BIND 9.2.3rc1 -- 9.4.0a0 ns.yahoo.com fingerprint (ns.yahoo.com, 220.127.116.11): ISC BIND 8.3.0-RC1 -- 8.4.4 ns1.google.com fingerprint (ns1.google.com, 18.104.22.168): ISC BIND 8.3.0-RC1 -- 8.4.4
=> Read fpdns man page.