Melick's Blog

In linux, file, folder, etc can accesse by three types of user groups. Owner Group Other and each user group has three types of permissions. read,write, and execute. As an example, (if user has read permision we denote it by using 1 and if not by 0 in binary ) Owner Group Other rwx    rw-      r--  111     110     100  7         6          4 we can use " ls -l " command to view files,folders,links with permissions. drwxr-xr-x 2 melick melick 4096 2008-11-23 00:32 Music this is the sample. so we look each and every element further. drwxr-xr-x first charactor "d" is for type of the file. there are three types. d = directory (folder) l = link (symbolic link, shortcut) - = file c = charactor device (ex:- /dev/ttys0) {try:- ls -l /dev/ttys0} b = block device (ex:- /dev/sda1)     {try:- ls -l /dev/sda1} now we consider the permission set in the above folder. rwxr-xrx- = rwx   r-x        r-x   owner  group   other   111       101       101   7           5      ...

All linx users, their passwords and other details are stored in a one file. It is " passwd " file which is in the "etc" folder. { /etc/passwd }             If we want to view password file {hm... there are several ways, but for the moment we will use "cat" command}.we will talk about "cat" command later. So in your command prompt {shell,terminal} run below command.  cat /etc/passwd This command will give you a file with several rows. One row is for one user. Let have a look on one row.  melick:x:1000:1000:melickrajee:/home/melick:/bin/bash  So let see what this line says. Following illustrate the format of the one line              username:password:Gid:Uid:Fullname:home folder:shell  So now we compare those two for further details.  melick       :x               :1000 :1000  :melickrajee  :/home/melick :/bin/bash  username :password :Gid    :Uid     :Fullname     :home folder  :shell melick - Username x(password) - x is not the pass...

Conducted workshop with the team CompSoc in Polonnaruwa Teaching Center . In here I conducted speaches on Database management systems , Web designning technologies and System Development Life Cycle.