What are seven fields in the Ubuntu Linux Password file

What are seven fields in the /etc/passwd file (Ubuntu Linux Password file)

      1          2    3     4         5                   6                   7

username:x:UID:GID:comment:home directory:shell

"username" is login name.
"x" is link of password.
"UID" stands for userID.
"GID" stands for groupID.

Common Filesystem Types used in Ubuntu / Debian Linux

Filesystem Types
* The most common filesystem types are:
ext2,ext3,ext4               The standard Linux filesystems

iso9660                          The filesystem used on CD-ROMs

proc                  Not a real filesystem, so uses none as the device.
                         Used as a way for the kernel to report  system information to user processes

Sysfs               exports information about devices and drivers from the kernel device model to user space
 
vfat                The filesystem used by Windows 95

auto                Not a real filesystem type. Used as a way of asking the mount command to probe for various
                       filesystem types, particularly for removable media

ReiserFS         is a general-purpose, journaled computer file system designed and implemented by a team at 
                       Namesys led by Hans Reiser      
 

 XFS       is a journaling filesystem,  developed  by  SGI

JFS       is  a  journaling  filesystem,  developed  by IBM 

 
tmpfs             is a common name for a temporary file storage facility on many Unix-like operating systems
 
usbfs              USB Device Filesystem.

Networked filesystems include
nfs (Unix-specific)
smbfs (Windows or Samba)

List of Server applications you can run in Ubuntu / Debian Linux

Name of some Server applications you can run in Ubuntu / Debian Linux

apache — Web server

boa — lightweight Web server
sshd — ssh server
sendmail — mail server
qmail — mail server
postfix — mail server
named — DNS server

bind    --- DNS Server
squid — Web proxy server
nessusd — penetration testing server
postgresql — database server
mysql — database server
oracle — database server

telnet — telnet server
wu-ftpd —  ftp server
vsftpf  ---- ftp server  
samba  --  windows file sharing


And more............

Useful Linux Network Commands for Ubuntu / Debian

Ubuntu Linux Useful Networking commands

    ifconfig – displays information network
    iwconfig – displays information from wireless
    sudo /etc/init.d/networking restart – reset the network
    /etc/network/interfaces – (file) manual configuration
    ifup interface – bring online interface
    ifdown interface – disable interface 

iwlist scan - shows wireless networks that are available in the area with basic encryption information
lshw -C network - Shows Details of Interface card and drivers of each networking device

lspci -nn - Shows PCI vendor and device codes as both numbers and names of hardware connected to the pci bus
lsusb - Shows USB connected hardware
lshw -C usb - Additional info on USB related hardware (good for USB dongles)

route -n - Lists kernel IP routing table — Good for troubleshooting problems with the gateway
sudo dhclient - Request IP address from DHCP server for specified interface
sudo dhclient -r - Release IP address associated with specified interface
/etc/udev/rules.d/70-persistent-net.rules - (File) which assigns logical names (eth0, wlan0, etc) to MAC addresses
cat /etc/resolv.conf - Lists DNS servers associated with network connections

How to Resize FAT Filesytem using Ubuntu LInux Utility : Fatresize

Fatresize is a command line tool for  resizing  MS Windows FAT16 / FAT32 file systems.
Fatresize Installation:

$ sudo apt-get install fatresize

Using Fatresize:
Fatresize follow the usual GNU command line syntax, with long options starting with two dashes (`-'). A summary of options is included below.
-h --help: Show summary of options.
-s --size: Re-size volume to SIZE[k|M|G|ki|Mi|Gi] bytes
-i --info: Show volume information
-p --progress: Show progress
-q --quite: Be quite
-v --verbose: Verbose (not version)

Fatresize Examples:

fatresize -s 2G /dev/evms/hdb2
fatresize -q -s 3G /dev/hde6
fatresize -i /dev/hdg3

How to Find the type of Memory Installed in Your Computer : Ubuntu Trick

In the case of upgrading, you have to know what type of memory installed in your machine. Capacity, Type, Speed etc.  here you can see a simple trick to find all details of your memory.

Open a terminal and type the following


$ sudo dmidecode --type memory

You can see the output like this

# dmidecode 2.9
SMBIOS 2.4 present.

Handle 0x0017, DMI type 16, 15 bytes
Physical Memory Array
    Location: System Board Or Motherboard
    Use: System Memory
    Error Correction Type: None
    Maximum Capacity: 8 GB
    Error Information Handle: Not Provided
    Number Of Devices: 4
Memory Device
    Array Handle: 0x0017
    Error Information Handle: Not Provided
    Total Width: 64 bits
    Data Width: 64 bits
    Size: 2048 MB
    Form Factor: DIMM
    Set: None
    Locator: J6H2
    Bank Locator: CHAN A DIMM 1
    Type: DDR2
    Type Detail: Synchronous
    Speed: 800 MHz (1.2 ns)
    Manufacturer: 0x7F4F000000000000
    Serial Number: 0x0007BF39
    Asset Tag: Unknown
    Part Number: 0x4A4D383030514C552D324720202020202020

Trash-cli : Manage Trash from Command line in Ubuntu Linux

By using a utility named trash-cli you can simply mange Trash from command line  

 The location of Trash folder in old GNOME version is (~/.Trash), in current versions it is in ~/.local/share/Trash. There is two sub folders named files and info. The files folder contains the files deleted and info directory consists of meta data for each deleted file.



First step, install trash-cli utility

$ sudo apt-get install trash-cli

It installs three commands,
1. list-trash to list down the files in trash
2. trash to move the file to trash
3. restore-trash to restore the file to original path

Usage:

$ trash love.txt      ( move the file love.txt to trash folder)

$ list-trash              (List the contents of Trash folder) 

       2011-10-27 22:46:28 /home/abc/love.txt



 $ restore-trash love.txt   (Restore the file love.txt) 

   0 2011-10-27 22:46:28 /home/abc/love.txt
What file to restore [0..0]: 0  (if there is more than one file list shows 1  2  3 etc)

How to Create Encrypted Folder in Ubuntu with Cryptkeeper

 We can create Encrypted Folder in Ubuntu using Cryptkeeper. Cryptkeeper is a system tray applet for Linux that is designed to provide you with simplified options to create hidden encrypted directories. You can save your important data on the password-protected and encypted directories and access at any time by displaying a hidden folder option in the system tray.

How to install cryptkeeper in ubuntu

Open a terminal and type the following

$ sudo apt-get install  cryptkeeper

Linux Then and Now (Linux Development Milestones )

Linux Then and Now (Linux Development Milestones )

Vinux : Ubuntu For Blind (visually Impaired users)

Vinux is a remastered version of the Ubuntu Linux Distribution optimized for visually impaired users. It provides a screen-reader, full-screen magnification and support for Braille displays out of the box! It can be run from a Live CD without making any changes to your hard drive. If you like it you can install it to a USB pendrive or to your hard drive either alongside Windows using the Virtual Version, or as a complete replacement for windows.
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