Bash: How to Swap Two Columns in a File

Often you may want to use Bash to swap two columns in a file.

You can use the following syntax with awk to do so:

awk ' { x = $2; $2 = $4; $4 = x; print; } ' player_stats.txt

This particular example will swap columns 2 and 4 in the text file named player_stats.txt.

Here is how this syntax works:

First, we create a variable named x (you can name this anything you want) to be equal to the values in column 2 of the file
Then, we assign the values from column 4 to be used as the values for column 2
Lastly, we assign the values from the variable x (which contains the values in column 2) to be used as the values for column 4

By using this syntax, we are able to swap columns 2 and 4 in the file while leaving all other columns in the same positions.

The following example shows how to use this syntax in practice.

Example: Use Bash to Swap Two Columns in a File

Suppose that we have a file named player_stats.txt that contains information about various basketball players.

We can use the cat command to view the contents of this file:

Suppose that we would like to swap columns 2 and 4 in the file.

We can use the following syntax to do so:

awk ' { x = $2; $2 = $4; $4 = x; print; } ' player_stats.txt

The following screenshot shows how to use this syntax in practice:

Bash swap columns

Notice that columns 2 and 4 in the file have been swapped.

All other columns in the file have remained in the same positions.