ODOC: locate

locate — Quick search for files

Summary :

Locate provides a secure way to index and quickly search for files on your system. The index database to make searching faster and file permissions and ownership info will give the security.


$ locate myfile — Locate myfile in the DB and Print the path.

$ locate -i MyFile — Same as above. But Case insensitive.

$ locate -q myfile — Run in Quiet Mode.

$ locate -n 10 myfile — Limit the no. of results shown to 10.

# locate -U mydir -o myDB — Create index DB starting at path mydir and store the index file in myDB.

Read: man locate

locate, odoc, linux, gnu/linux

Firefox 1.5 in Ubuntu Breezy

Ubuntu Breezy 5.10 users search for installing Firefox 1.5 on their boxes. So, I thought of writing a tutorial. I am writing this using the information in the Ubuntu Wiki. There are a few points to note before installing Firefox 1.5.

  • Don’t remove the Ubuntu version of Firefox, otherwise, you will break a few packages
  • You will no longer get automatic updates through repositories, but the auto-updater built in firefox is enough
  • The Totem video plugin doesn’t work. I don’t use this particular plugin. Anyway you can install the package mozilla-mplayer.
  • You need package libstdc++5 installed.
    sudo apt-get install libstdc++5
  • There is a bug in Firefox which causes an error dialog to be displayed, each time FF starts up saying Firefox could not install this item because of a failure in Chrome Registration. Do this for a work around:
    sudo mkdir -p /opt/firefox/extensions/talkback@mozilla.org
    sudo touch /opt/firefox/extensions/talkback@mozilla.org/chrome.manifest


  • I would suggest you backup your bookmarks and settings by
    cd ~/.mozilla/firefox/*.default
    mkdir ~/Desktop/ffsettingscp bookmarks.html cert8.db cookies.txt formhistory.dat 
    key3.db signons.txt history.dat  mimeTypes.rdf ~/Desktop/ffsettings
  • Download firefox-1.5.tar.gz and change to the directory you downloaded.
  • Extract it to /opt/firefox
    sudo tar -C /opt -xvzf firefox-1.5.tar.gz
  • Link to your plugins and remove totem-mozilla as it doesn’t work with FF 1.5
    cd /opt/firefox/plugins/sudo ln -s /usr/lib/mozilla-firefox/plugins/*
    sudo rm libtotem_mozilla.*
  • Change to your home directory and rename your old profile(just as backup)
    cd ~mv .mozilla .mozilla.ubuntu
  • To ensure it is used as the default version, modify the symbolic link in /usr/bin
    sudo dpkg-divert --divert /usr/bin/firefox.ubuntu --rename /usr/bin/firefoxsudo
    ln -s /opt/firefox/firefox /usr/bin/firefox

    The dpkg-divert command will move the original system-wide /usr/bin/firefox to a new name. The ln command will place a symbolic link to the newly installed firefox in /usr/bin.

  • Try the new firefox by typing firefox
  • Restore your old data
    cd ~/Desktop/ffsettingsmv * ~/.mozilla/firefox/*.default
  • Restore your search plugins
    sudo cp -i --reply=no /usr/lib/mozilla-firefox/searchplugins/* /opt/firefox/searchplugins/
    sudo cp -i --reply=no ~/.mozilla/firefox/*.default/search/* /opt/firefox/searchplugins/
  • To ensure that other programs use the 1.5 version and not the older 1.0.7 version, goto Preferences>Preferred Applications in the System Menu. Under the Web Browser tab, choose custom and enter firefox %s

I hope this tutorial would really help many in installing Firefox and thereby enabling them to view the web in a totally different view. If anyone got any problem in installing Firefox or has got a better way, please discuss here.

Technorati Tags: , ubuntu, ubuntu linux, , linux

ODOC: showkey

showkey — Examine the codes sent by the keyboard

Summary :

showkey prints to standard output either the scan codes or the keycode or the `ascii’ code of each key pressed. It can be used to check the keyboard driver and key mappings.


$ showkey — Show the interpreted keycode.

$ showkey -k — Same as above (Default Option).

$ showkey -s — Show the raw scan-codes of the keys.

$ showkey -a — Show the Decimal/Octal/Hex values of the keys.

If Showkey is in keycode/scancode mode, then you have to wait 10 second to exit. In ASCII mode, Press Ctrl+D to exit.

Read: man showkey

showkey, odoc, linux, gnu/linux

PyPy – Python Implementation in Python

PyPy is a Python implementation written in Python. Of late people have started to implement a language in itself to demonstrate the versatility of the language and to show its applicability for large projects. Writing operating systems and compiler/interpreters for languages are the most complex things in software development. Since PyPy is implemented in Python, it provides the high level of abstraction and compactness of the language. This makes the implementation easy to understand than in C. Currently it is not well optimised, but in future they may be optimisations to allow prorgams to run faster than CPython.
python, pypy, cpython, c

ODOC: arp

arp — Manipulate the Address Resolution Protocol cache

Summary :

It is used to view/add/del kernel’s ARP cache table entries.


$ arp — Show ARP Cache table.

$ arp -v — For detailed output.

$ arp -n — Show Address in numeric. Don’t try to resolve the names.

$ arp wify — Show the ARP entry for wify host.

$ arp -a wify — Same as above.

$ arp -t ether — Only show ether HW class entries.

$ arp -i eth0 — Show ARP entries of eth0 interface.

# arp -d — Delete the ARP entry for this IP.

# arp -s 00:0B:22:33:44:55 — Add a new entry.

# arp -f arps.txt — Same as above. Here data will be taken from the arps.txt file.

Read: man arp

arp, odoc, linux, gnu/linux

ODOC: ifconfig

ifconfig – CONFIGure a `network’ InterFace

Summary :

ifconfig is used to display/configure the kernel-resident network interfaces. It is used at boot time to set up interfaces.


$ ifconfig — Show info abt the active network interfaces like IP Address, MAC address, Subnet mask, and status.

$ ifconfig -a — Show the status of active and inactive interfaces.

# ifconfig eth0 down — Deactivate/Shutdown the eth0 interface.

# ifconfig eth0 up — Activate the eth0 interface.

# ifconfig eth0 netmask up — Activate an interface with specific IP address.

# ifconfig eth0:0 netmask broadcast

# ifconfig eth0:1 netmask — Creating alias for eth0, ie Assign more than one IP address to eth0.

# ifconfig eth0 arp — Enable the use of the ARP protocol on eth0.

# ifconfig eth0 -arp — Disable the use of the ARP protocol on eth0.

# ifconfig eth0 promisc — Enable the promiscuous mode on eth0.

# ifconfig eth0 hw ether 09:08:07:06:05:04 — Change eth0 MAC address.

# ifconfig eth0 mtu 1412 — Change Max Transfer Unit of eth0.


  • Deactivate the interface before changing the IP/MAC.
  • Note down the original MAC, Otherwise Reboot needed to get the original MAC Address.
  • Some command sequence needs super user permission.

Read : man ifconfig

ifconfig, network, odoc, linux, gnu/linux

ODOC: id

id – Print real & effective UIDs and GIDs

Summary :

It prints the user’s info like user id, group id, user name, etc.,


$ id — Print UID, GID, Groups.

$ id -r — Print only the real user ID.

$ id -u — print only the effective user ID

$ id -nu — Print only user name.

$ id -g — print only the effective group ID.

$ id -ng — Print only group name.

$ id -G — Print all group IDs

$ id -nG — Print all groups name.

$ id user1 — Print info abt user1.

Real UID is the UID of the user, who created. Effective UID is used to evaluate privileges of the process to perform a particular action.

Read : man id

id, odoc, linux, gnu/linux

ODOC: rdate

rdate — Get the time from Remote machine.

Summary :

It connects to an Remote Time Server over a TCP/IP network, printing the returned time and/or setting the system clock. The time in remote server is maintained properly. So that all machines can get the time from that server.


$ rdate -p — Print the time returned by the remote machine.

$ rdate -s remote.pc.com — Set the system time to the time returned by the remote machine (Need Root permission).
$ rdate -u myserver — Use UDP instead of TCP as the transport.

$ rdate -l myserver — Use syslog to log errors and output (Useful when it is used in cron jobs).


  • Remote server should run the time service in port 37.
  • Firewall should not block port 37.

Read : man rdate

rdate,odoc, linux,gnu/linux, date, time, remote+system

ODOC: uniq

uniq — Remove duplicate lines from a SORTED file.

Summary :

It prints the unique lines in a sorted file. If input is not sorted then, only adjacent duplicate lines are discarded.


$ uniq myfile — Print only unique lines.

$ uniq -i myfile — Ignore case when comparing.

$ uniq -u myfile — Print only lines, Which is not duplicated.

$ uniq -c myfile — Print all unique lines with no .of occurrence.

$ uniq -d myfile — Print only duplicate lines. If a line duplicated then, only one line will be printed.

$ uniq -D myfile — Print all duplicate lines.

$ uniq -w5 myfile — Use only first 5 Chars for checking the uniqueness of the line.

$ uniq -f2 myfile — Don’t compare up-to 2nd field.

$ uniq -s2 myfile — Don’t compare up-to 2nd char.

$ sort myfile | uniq > output — Sort myfile & store the uniq output.

Read : man uniq

odoc, uniq,linux, gnu/linux