How to echo commands as they are executed in a shell script

It is helpful to log the shell commands being executed when running a bash script (especially when debugging it).

As an example, we will use this bash file.

#!/bin/bash  
  
Name="Ankur"  
  
echo $Name  
ls | wc -l

When we execute this script, we can see this as the output.

Ankur
10

Solution 1

You can use set -v in the shell script.

#!/bin/bash  
set -v

Name="Ankur"  
  
echo $Name  
ls | wc -l

On running this script, we can see

Name="Ankur"  

echo $Name
Ankur
ls | wc -l
10

Note: You can turn off this behaviour by using set +v.

You can see that although it showed the command being executed, it did not expand the variable in the echo command.

Solution 2

You can use set -x in a shell script.

#!/bin/bash  
set -x

Name="Ankur"  
  
echo $Name  
ls | wc -l

On running this script, we can see

+ Name=Ankur
+ echo Ankur
Ankur
+ ls
+ wc -l
10

Note: To turn off this behaviour, you can use set +x.

It showed the executed command and added a + sign before the command. It also expanded the variable name.

Conclusion

We looked at 2 ways of showing the commands being executed in a shell script. These can be extremely helpful when debugging your shell script.