yesterday i have learned and hearing :(Because its very important for every human life).


niraiya avamangal var um life la .but Ethan yell-am oru burn panakudiya visayama eduthukama , una

Vega paduthakudiya oru visayama eduthudu nada podu . entha pala avamanagal matum tha una great

and successful ah erukira oru manithana matrum.  epo etha yella visathium learn panikara .pinala

etha  successful ah mathura.

oru visathai kathu tharavagale mathavagatha . first , give salute for them.


vehicle ah eyakura petrol ah erukanum .erutha nee unoda goal success

happy life:

Its learned for few things:

1. Ignore the negativity.

2. Be positive for all the time.

3. Many failures are guided for one huge success.

4.Thanks for teaching life in harmful  people

5. Be kind ful

6. BE helpful for others.

7. Be Brave heart .

8. Don't loss confidence for all time.

9. Don't forgot about your  parents.


Because life is  temporary. its not just nothing .whenever  the come money, leadership , power, etc.....

but mankind is very important. the one thing make for good human-being.

Age is not realize for real maturity. the great experience is realize for real maturity.

Scripting basics:

1.Shell Scripts are text file.It should be all commands are executed

Because the shell scripts is do for automatically process and daily repeated for command line:

1. performing system administration and trouble shooting .

2. creating the simple applications.

3.Manipulate the text or files.

4. Automating commonly used command lines.


The prompt can vary every time displayed and using the

Some common escape sequences:

1. \u  =  user name = (if you have multiple accounts).

2.\w  = Current working directory

3. \h  =  Host name( not fully qualified with domain name)

4.\$  =  if you are non- privileged user  . #   =    if you are privileged user. sometimes if you are

become an super user also

5.  \!  The history number of the current command also.

Man command is used and solving  the mowin problems:

such as a,

1. Man command :

Its shows the manual pages.

Searching the manual :

man -k command:

The above keyword listing the  all matches pages.

While viewing a man page

q quit :

Because its used for quit page

/text command:

Its used for searching the text.

n/N command:

Its goes for next/previous matches.

Linux file system and directories organization:

1. Files and directories are organized with single- root inverted tree structure.

2. names are case-sensitive.

3.File system is begins with the root and forward slash

4.paths are delimited by /

or

1. cal command:

cal  = displaying the calendar for every month and year

For example like as a ,

cal 2009

Its displaying the full 2009 year events.

cal  6 2008

cal -2  2008

The above two commands is displaying the few changes for calendar.

2. Date command:


Date format like as a , mm/dd/yy

So its mentioned the command is displaying like,

date  '+%x'    .

Otherwise  user want some help .so command is appeared to,

date ----help.

Command line expansion:

Tilde command: (~):

May for your user home directory:

$ ~ cat /.bash_profile

.bash_profile is own user's home directory.

may its refer for another user home directory.

$  ls ~nandhini/.public_html

.public_html  = Its refer for another user's  home directory.

When the tilde command is used, whether  the command is referring for your own's home directory.

remove directory is a =  rmdir

remove directories and contents is used as a rm  -r

Cp command:

This command is displaying the copy the files.

rm command:

This command is used to remove files.

mv command:

This command is used to move And rename the files.

Cd command:

Change Directory.

Ls command:

Listing the contents of the current working directory and specific working directory.

Root directory:

All files and directories are considering the root directory .because the root directory not contained 

for anything from top and bottom. 

Sub-directory:

Anything contained for inside the directory .so its called as a sub-directory.

Change Directory:

1. "Cd ":

This command is used for moving your current working directory or user's home directory.

"/":

Root directory:

The root directory is always represented symbols like as a ,  "/". 

The root directory is change into your current working directory:

Cd  /

Because the root directory in main importance for everyone stream.then other directories are defined by below.

Cd..

To a directory  one level up from a current working directory.

Moving scenario like as a,

Parent directory  _  current working directory.

Because its take one step to a back . meaning of contents like is a parent to current working directory.

Cd.. will switch into parent of your current working directory.

Tilde command(~):

Its referring for your user's home directory.

its the user name is username and home directory is home

Cd ~

This functionality is put into the same like as a,

Cd/ h/ home/username

Otherwise it put like as a,

Cd ~/documents

Cd - :

When this command is used to moving your previous working directory

For example like as a,

Cd ~

pwd

/user/home

Cd documents/ economy

pwd

Cd -

This command is reach on previous working directory.

Command line expansion:

Command  Expansion: $ ( )

$ echo " This name is a $(nandhini)"

Because its displaying the output of one command as an argument to another.



Brace line expansion:

{}:

$ echo stu_mark{100,99,98}

Stu_mark100, Stu_mark99  Stu_mark98

rm -f  Stu_mark{100,99,98}

This command is used to removing files and directories with force

Create directory:

mkdir directory  name

Becasue this command give accessing permission to all .such as a read write and execution .


mkdir -p

-p is describing like as to displaying the multiple directories in the multiple time at the same level.

1. File permission:

Linux Commands: 

1. Pwd  =  Present Working directory.

Its referred for abosulate path in your current working directory. even if analyzed for in which user are current working directory.

2. ls Command:

ls command is displaying the contents of the current working directory and specific working directory.

ls -a:

This command is used and displaying the hidden files and directory.whose its begin with (dot) = .

For example like as, 

.bash_profile , bash_account, .public_html

ls -l:

This command is displaying the extra information .because its displaying the long  listing contents with more information.

ls -d:

Its displaying for only directories . even not to their contents also.

ls -ld:

This command is displaying the directories and symlink information.

ls -R:

Re-curse through the sub_directories