Which symbol should I use to redirect the error output to the standard output?

You should use the symbol "2>&1" to redirect the error output to the standard output in a Unix/Linux shell. Here's how you can do it:

1. First, you need to understand that in Unix/Linux, standard output is represented by '1' and standard error is represented by '2'.

2. The '>' symbol is used for redirection.

3. So, when you want to redirect the error output to the standard output, you use '2>' to start the redirection of the error.

4. Then, you use '&1' to specify that you want the error output (2>) to go to the same location as the standard output (1).

5. Therefore, the full command becomes '2>&1'.

This command is typically used in conjunction with other commands. For example, if you're running a command called 'mycommand' and you want both the standard output and standard error to go to the same file, you would use:

mycommand > myfile.txt 2>&1

This command redirects the standard output to myfile.txt and then the '2>&1' redirects the error output to the same location as the standard output (which is myfile.txt).