priyankasobhila / learn-shell-1

learn-shell

We will learn shell scripting topics.

List of Shell Topics

1. How to write shell script file
2. Printing
3. Variables
4. Inputs
5. Conditions
6. Loop
7. Function
8. Exit Status
9. Quotes
10. SED Editor

SED Command Options

delete some lines 
    - based on line numbers 
        sed -i -e '1d' passwd 
    - string based delete 
        sed -i -e '/nologin/ d' passwd

add some lines 
    - sed -i -e '1 a Hello' -e '/monogd/ a Hello World' passwd 
modify(change) some lines 
    sed -i -e '2 c Hello Universe' -e '/centos/ c Hello Galaxy' passwd


delete some words 
    sed -i -e 's|Hello||g' passwd 
modify(substitute) some words 
    sed -i -e 's|bin|BIN|g' passwd 
    sed -i -e '10s|bin|BIN|g' passwd 
Instead of | we can use / , ?, :, ;, #, @

PROBLEM:

1. If input is not given then script should fail