The echo command is one of the most basic and important commands in scripting/programming! This command displays or prints arguments at the terminal. The command is included in all distributions (operating systems) as either the shell or bash. Usually, developers or programmers use echo commands in both debugging and building of products such as websites, applications, Operating Systems, etc.
As part of system administration, we can use the echo command to create shell scripts or batch files. This guide explains how to use the various options for echo commands. All examples of echo commands below were tested on RHEL/CENTOS 7.6.
The Global Syntax of echo command with options:
echo [OPTION] [input string]
The following tabular gives you the possible options in the echo command:
1. How to simply input a text to get the output using the echo command?
# echo LinuxTeck A complete learning blog
Output:- LinuxTeck A complete learning blog
Note: The above echo command simply prints the specified text to the standard output.
2. How to print a variable?
# x=100
# echo The value of x =$x
Output : The value of x = 100
Note: Here the variable name is 'x' and the value assigned to x is '100'. Make sure there is no space between the variable and value. Then we can use the echo to print the value of 'x'.
3. How to create Alerts while printing?
# echo -e "LinuxTeck A complete learning blog\a"
Output: LinuxTeck A complete learning blog
Note: Here we use '-e' to enable the interpretation of backslash escape sequences and '\a' option Alert a beep sound while prints
4. How to add a new line?
# echo -e "LinuxTeck \nA complete learning Blog"
Output: LinuxTeck
A complete learning Blog
Note: '-e' used an interpretation of backslash escape sequences and '\n' tab used for adding a new line and it will be printed next to the previous line.
5. How to add a horizontal tab to your content?
# echo -e "LinuxTeck \tA \tComplete \tLearning \tBlog"
Output: LinuxTeck A Complete Learning Blog
Note: '-e' uses an interpretation of backslash escape sequences and '\t' creates a Horizontal space between the content, it is similar to using the TAB key option from the keyboard.
6. How to add a Vertical tab to your content?
# echo -e "LinuxTeck \vA \vComplete \vLearning \vBlog"
Output : LinuxTeck
AComplete
Learning
Blog
Note: '-e' uses an interpretation of backslash escape sequences and '\v' creates a vertical space between the content, it is also similar to using the TAB key option from the keyboard but vertically.
7. How to suppress the content to display after a certain portion?
# echo -e "LinuxTeck A Complete Learning Blog \cLinux | AWS | VMware | DevOps"
Output: LinuxTeck A Complete Learning Blog
Note: '-e' uses an interpretation of backslash escape sequences and '\c' option will mainly be used to eliminate the contents. This means it will omit to display the contents after the '\c' option.
8. How to use Carriage Return?
# echo -e "LinuxTeck is \rA Complete Learning Blog"
Output: A Complete Learning Blog
Note: '-e' used an interpretation of backslash escape sequences and '\r' is nothing but to delete the text before it. Means if you want to remove content from a certain portion to display in the output you can use \r just before it. In the above example, you can see LinuxTeck has been removed in the output.
9. How to use Backspace for your content?
# echo -e "LinuxTeck- \bA \bComplete \bLearning \bBlog"
Output : LinuxTeck-ACompleteLearningBlog
Note: '-e' uses an interpretation of backslash escape sequences and '\b' eliminates all the spaces in between the content. In the above example, you can see all the spaces have been removed from 'A Complete Learning Blog'.
10. How to add Form Feed to your content?
# echo -e "LinuxTeck \fA \fComplete \fLearning \fBlog"
Output: LinuxTeck
A
Complete
Learning
Blog
Note: '-e' uses an interpretation of backslash escape sequences and '\f' option will separate output pages instead of newlines.
11. How to print all the files and folders?
# echo *
Output : testfile1 testfile2 testfile3 testfile4 testfolder
Note: This command is similar to the 'ls'. It will simply print all the files and folders. In the 'ls' command we can easily identify the files and folders by color combination whereas, in echo, it shows only with the plain white color by default.
12. How to print some particular extensions of files?
#echo *.log
Output: boot.log vmware-vmsvc.log wpa_supplicant.log Xorg.0.log Xorg.9.log yum.log
Note: The above example shows how to find the extension of all the .log files.
13. How to redirect the output to a file with a nonstandard output?
# echo "LinuxTeck" > test
Output : # cat test
LinuxTeck
Note: Use echo to redirect the operator to output to a text file and not standard output.
I hope this article will help you to learn a few steps towards echo commands in Linux! This is just a startup in the scripting world. Do practice with various options and it helps you to understand. Drop me your feedback/comments.
Thank you!
