The Linux read command provides you the option to prompt for user input. Once the user-provided input and hits enter, the command store provided input to a variable. Which can be used later in the shell scripts.
In this tutorial, you will learn, how to prompt for user input in a shell script. Also, help you with accepting passwords from users in hidden characters.
Take Input on Termianl
Let’s begin with input directly on terminal. Open a terminal on your system and type:
read x
Here read is the Linux command and “x” is the variable, where the input value will be stored.
Hit enter after typing the above command. You will see a blank line without a prompt. It means the shell is waiting for your input. Type some text and hit enter button. You will find the prompt again.
Now, verify that the input value is stored in a defined variable. To confirm it, print the variable value with the echo command.
echo $x
There is no need to define any data type for variables. Shell automatically adjusts the type based on the user input.
Lets’ go with a sample shell script to take user input.
Shell Script to Prompt User Input
Write a sample shell script to prompt for the user input and store it in a variable. Make sure to print a proper message on the screen before prompting for input. Store the input value in a variable and then print it in with a welcome message.
Create a new file “input.sh” and write below script:
1 2 3 4 5 | #!/bin/bash echo "Enter Your Name: " read x echo "Welcome ${x}!" |
Save your file and close it.
chmod +x input.sh./input.sh
In the above script, you found that the input is prompted in a new line. To make it better, use the -p option to print the message before input with the read command. With this, we will skip the first echo line.
Edit your script and make the following changes.
1 2 3 4 | #!/bin/bash read -p "Enter Your Name: " x echo "Welcome ${x}!" |
Again execute the same script and see the outputs:
./input.sh
How to Input a Password in Shell Script
The password input should be hidden on the screen, similar to what the Linux shell does when setting a password on the screen. Passwords must not be visible on the screen.
The read command provides the silent mode option with “-s” to hide the input characters from the screen. Let’s create a sample script to take password input from the user.
vim input-pass.sh
Add the below script.
1 2 3 4 | #!/bin/bash read -s -p "Enter a Password: " x echo "Your password is - $x" |
Save the file and close it.
chmod +x input-pass.sh./input-pass.sh
Conclusion
This how-to guide helped you to understand the user input in shell scripts. Additionally provides you an example to take input of a password in the shell script.
8 Comments
Hi Rahul,
Currently im looking for pass the input value to grep command to fetch the output. at end im facing below message also not sure what i passed is correct.
read -r “client name” input
case $input in
jobs -report | grep “$input”
jobs command doesnt have any parameter to pass so i need to grep the from -report. so how to pass the input read value to grep to display the output.
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Hi,
Can you let me know is there an alternative of “read” command. My code is like this:
————————————–
while read line
do
print “Do you want to continue”
read flag
…..
…..
…..
done > file.txt
———————————
Here the second read command (to get the user input) is not working.
Please provide a solution if you have.
Thanks.
great post exactly what i was looking for
Hello Rahul Sir ,
i want help for writing code
Q. take input from user in form of yes or no .
-> “Do you want to know in which Directory you are [ y | n ] “
This will help you: https://tecadmin.net/bash-script-prompt-to-confirm-yes-no/
Hello Rahul i need help with shell program i’m novice.
You have very nice collection of linux commands Rahul.