How to assign standard error stream output to a variable in bash?

Question

I know that we can assign the output of a command in a script as below:

res=$(ls)    # assign the output of ls to res

Now I want to assign the error message to a variable:

res=$(XXXXXXX)

When I execute the script, which contains the code above, I get an error message on the terminal: command not found, whereas res is still empty.

Is it possible to assign command not found to res while there is nothing shown on the terminal?

Possible duplicate of [How to store standard error in a variable in a Bash script](https://stackoverflow.com/questions/962255/how-to-store-standard-error-in-a-variable-in-a-bash-script) — PesaThe, Jan 11 '18 at 12:09
@PesaThe: I saw that but OP says `so redirecting stderr into stdout is not helpful, in this case.` — Inian, Jan 11 '18 at 12:11
@Inian oops, I saw this [answer](https://stackoverflow.com/a/962268/6176817) and instantly thought OP tried to do exactly the same thing. — PesaThe, Jan 11 '18 at 12:13

Inian · Accepted Answer · 2018-01-11T15:01:51.170

2

Yes it can be done, just make sure to send stderr(2) stream to stdout(1) and suppress stdout to NULL(/dev/null)

res=$( non_existent_command 2>&1 >/dev/null )

edited Jan 11 '18 at 15:01

answered Jan 11 '18 at 12:07

Inian

1 Answers1