Question: I have seen 

```
2>&1

```

at the end of a bash command. What does this mean? Is it some kind of output redirection?

Thanks!

Answer: 
Short: It redirects all output made on `STDERR` to `STDOUT`.

`>` is a redirection operator which will - in the simplest form - redirect all output on `STDOUT` into a file.

```
test.sh > file

```

If you prefix `>` with a number it uses the output from this specific file descriptor - 2 in your example. 1 is stdout, 2 is stderr.

```
test.sh 2> file.err

```

will redirect all output from descriptor 2 = stderr to the file.

If you use the special notation `&1` instead of a filename, the output is not written to a new file, but instead to the file descriptor with the given number, in this case 1.
So:

```
test.sh 2>&1

```

redirects from file descriptor 2 (stderr) to file descriptor 1 (stdout)

It's useful if you want to collect all output regardless of where it happened (stdout or stderr) to further processing, like piping into another program.
1 is stdout. 2 is stderr.

`2>&1` simply points everything sent to stderr, to stdout instead.

You will get more info about this : [here](http://www.cyberciti.biz/faq/redirecting-stderr-to-stdout/)