# Writing to file using bash redirection

Hello.

In this article, we are going to write to a file using a file descriptor.

Let's go!

The file we want to work with is `animals.txt`:
```
$ cat animals.txt
dog
horse
cow
chipmunk
```

First we have to tell bash to set up the redirection required.
```
$ exec 4>>animals.txt
```

This opens `animals.txt` for writing and assigns file descriptor 4. Note the use of `>>` instead of `>` so we can append to the file.

Now let's try adding a line to `animals.txt`.
```
$ echo foobar >&4
```

This writes `foobar` to file descriptor 4 which is the same as writing to `animals.txt`.

We can confirm.
```
$ cat animals.txt
dog
horse
cow
chipmunk
foobar
```
As you can see `foobar` is appended. Success! 

We can close file descriptor 4 now.
```
$ exec 4>&-
```

Nice!