In bash script, if you wish to apply multiple conditions using if statement then use ‘ if elif else’. In this type of conditional statement, if the first condition is met then code below it will be executed otherwise next if condition will checked and if it is not matched then commands...
The if in a Bash script is a shell keyword that is used to test conditions based on the exit status of a test command. An exit status of zero, and only zero, is a success, i.e. a condition that is true. Any other exit status is a failure, i.e. a condition that is false. ...
Here the “-z” option is used with the “test” command to check if the input argument is an empty string or not. The script will output an error message and exit with a status code of 1 if the input argument is an empty string. Otherwise, the script will continue executing, below ...
Welcome to the Bash for Beginners Series where you will learn the basics of Bash scripting. In this video, Gwyn puts together several concepts we've covered in previous videos into one more complex and complete Bash script. We'll see how to use condition
When trying to understand the working of a function like if-else in a shell script, it is good to start things simple. Here, we initialize two variables a and b, then use the if-else function to check if the two variables are equal. The bash script should look as follows for this ...
Nested Loops in Bash A nested loop is a loop within a loop. When working with arrays, you might find a situation where you need to loop through multiple arrays simultaneously. For example, you might have a script that needs to compare the elements of two arrays. Here’s an example: ...
For example, let’s say that you want to check if the file “/etc/passwd” exists on your filesystem or not. In a script, you would write the following if statement. #!/bin/bash if [[ -f "/etc/passwd" ]] then echo "This file exists on your filesystem." ...
3. Usingprintfto Answer Multiple Questions Sometimes, we may need to write a script that answers multiple prompts – for example, to automate software installation or cryptographic key generation. If a script requires multiple inputs, we can simply useprintfto answer them in the specified order....
In this post, we will learn how to debug a bash shell script in linux.Using bash command line options like -n, -v and -x we can do the debugging.
You can have awhileloop to keep checking for that directory's existence and only write a message while the directory does not exist. If you want to do something more elaborate, you could create a script and show a more clear indication that the loop condition became true: ...