Exercise 3

Create a file called echo-1.sh (use the touch command to create the file)
$ touch echo-1.sh

Create a script called variable-1.sh
This script will create a variable called NAME
Assign the value “John” to the variable and print out “Hello John”

Write a script called myargs.sh
That prints out the first argument passed into it

Create a file called my_name.sh
The script should first print out “What is your name? > ”
(note the spaces !)
The user then enters their name
The scripts prints out “Hello <name>”

Our script my_name.sh has a problem
A user doesn’t have to enter a name at all !
This would end up with our variable being an empty (null) string
Make a new copy of this script and call it my_name-2.sh
Bonus points, use the cp command to copy the file
cp my_name.sh my_name-2.sh
Copy the file my_name.sh and call it my_name-2.sh 

Change the code in my_name-2.sh so that if a user enters an empty string it prints out
“All right then. Keep your secrets.”
Otherwise, if they enter a name the script should return “Hello <name>”
Remember [ -z “$var” ] tests if $var is empty

Make a copy of the file my_name-2.sh , call it my_name-3.sh
Use cp !
Change the code so that:	
If there is no input it prints “All right then. Keep your secrets”
If the name entered is “Lebowski” print out “Hello Dude”
Otherwise just print out the name
Remember [“$a” = “$b”] checks if two strings are the same

Write a script called ls-1.sh while lists all the text files in a directory

Write a script called allargs.sh which prints out each argument passed on a separate line

Take the output from one program and pass it to another
syntax:
cmd_one | cmd_two
The standard output for cmd_one will be passed into cmd_two
Write two scripts, one which produces and output, and another which reads it in


Create a file called overwrite.sh which writes (>) the string “Hello There” to a file called output.txt

Create a file called append.sh which appends (>>) the string “Hello There” to a file called output.txt  

write a program called combine-1.sh that combines a.txt and b.txt into a new file called c.txt 

write a program called combine-1.sh that combines a.txt and b.txt into a new file called c.txt 

Make a copy of combine-2.sh, call it combine-3.sh 
Change the functionality so that if no file is passed in as a parameter it will use a default file called “tmp.txt”

Copy combine-3.sh and call it combine-4.sh
Change the functionality so that instead of a.txt and b.txt it will loop through and append all text files inside the current directory.
Look back to last weeks notes to remember how to find all text files

Create a file called search-1.sh that searches for the string “lamb” using a case insensitive search inside the a file called mary.txt

create a file called search-2.sh
The file should use grep to search a file called users.txt to list every user whos name starts with “M”

Copy search-2 and call it search-2a
Modify the code so that instead of searching users.txt, it will perform a serach on every text file in the current folder