Often you may want to use Bash to replace a line in a file based on line number.
The easiest way to do so is by using sed with the following syntax:
sed -i '2 cBoston Celtics' teams.txt
This particular example will replace the text in line number 2 of the file named teams.txt with the text “Boston Celtics” instead.
Here is what the various commands do:
- -i: Specifies that the file should be modified in-place
- 2: Specifies the line number to match in the file
- c: Specifies that the line should be changed to the text following the c
The following example shows how to use this syntax in practice.
Example: How to Replace Line in File Based on Line Number in Bash
Suppose that we have a file named teams.txt that contains the names of various basketball teams.
We can use the cat command to view the contents of this file:
Suppose that we would like to change the text on line number 2 of the file to be “Boston Celtics” instead.
We can use the following syntax to do so:
sed -i '2 cBoston Celtics' teams.txt
The following screenshot shows how to use this syntax in practice:
Notice that when we use the cat command to view the updated contents of the file we can see that line number 2 now contains the text “Boston Celtics”, just as we specified.
All other lines in the file have remained unchanged.
Feel free to replace 2 with the specific line number that you would like to replace in your own file.
Related Tutorials
The following tutorials explain how to perform other common tasks in Bash:
Bash: How to Find Duplicate Lines in File
Bash: How to Delete All Empty Lines in File
Bash: How to Count Number of Unique Lines in File
