How do I combine stdout and stderr for different shells?

Question

I know the answer for some shells, e.g. with cmd.exe you can:

some.exe > out.txt 2>&1

How do you achieve the same for other shells (bash, ksh, tcsh, powershell, etc)?

Answer 1

For csh and tcsh

some.exec >& out.txt

Answer 2

In bash you do exactly the same.

./some_exec > out 2>&1

Answer 3

In Powershell it is exactly the same:

2>&1      Sends errors to the        get-process none, powershell 2>&1
          success output stream.

(from about_Redirection).

In bash and ksh at least I also know it works this way.

It seems to be a common convention.

A quick way to find out about it is by opening the man page of the shell and do a search for &1 (with / and then typing &1). This rarely occurs in other contexts.