Often you may want to use Bash to remove leading zeros from a variable.
There are two common ways to do so:
Method 1: Remove Leading Zeros Using sed
no_zero=$(echo $my_number | sed 's/^0*//')
This particular example will remove all leading zeros from the variable named my_number and store the results in a new variable named no_zero.
This method uses the sed command s/ to perform a “substitution”, by substituting all leading zeros with nothing, which has the same effect as removing all leading zeros from the variable.
Method 2: Remove Leading Zeros Using expr
no_zero=$(expr $my_number + 0)
This particular example will also remove all leading zeros from the variable named my_number and store the results in a new variable named no_zero.
This method uses the expr command to evaluate the result of adding zero to the variable named my_number, which returns the result with all leading zeros automatically removed.
The following examples show how to use each of these methods in practice.
Example 1: Remove Leading Zeros Using sed
Suppose we create a variable in Bash named my_number that contains the following value:
- 00004588
Suppose that we would like to remove all leading zeros from this variable.
We can use the following syntax with sed to do so:
my_number=00004588
no_zero=$(echo $my_number | sed 's/^0*//')
The following screenshot shows how to use this syntax in practice:
Notice that this returns the value from the my_number variable with all leading zeros removed.
Example 2: Remove Leading Zeros Using expr
Once again, suppose we create a variable in Bash named my_number that contains the following value:
- 00004588
Suppose that we would like to remove all leading zeros from this variable.
We can use the following syntax with expr to do so:
my_number=00004588
no_zero=$(expr $my_number + 0)
The following screenshot shows how to use this syntax in practice:
This returns the value from the my_number variable with all leading zeros removed.
Related Tutorials
The following tutorials explain how to perform other common tasks in Bash:
How to Remove Spaces from String in Bash
How to Remove newline from String in Bash
How to Remove Last Character from String in Bash
