init script '/dev/tty: No such device or address' error on redirect

Question

I will include the entire script at the bottom for reference. This script gets called toward the end of the init scripts. If I run the script after logging in, it runs with no error. 30000 foot view, trying to execute a rsync command and capture any errors into a variable. I am using bash 3.5.6pl. Here is the line that is the culprit: ``` LogMessage+=$(rsync -rpltDzv --delete --progress /mnt/WinPrimary /mnt/WinBackup 2>&1 >/dev/tty)$'
' ``` What is stored in the variable, which does get written to a log, is: ``` /etc/Braums/scripts/Sync1to2.sh: line 47: /dev/tty: No such device or address ``` I googled the technique for the syntax to capture stderr but not stdout. I want the progress to show and not capture all the screen stuff. So the init calls the script “Sync1to2.sh”. Which has the above command. If I run the same script from the command line after logging in, it runs as expected. Here is the entire Sync1to2.sh script. I don’t do bash scripts too often, so be careful and don’t hu…

Accepted Answer

Rather than writing to `/dev/tty`, how about simply swapping stdout and stderr?

```
yourcommand 3>&2 2>&1 1>&3 3>&-
```

This is the redirection equivalent of swapping the contents of two variables using a third temporary variable:

```
3>&2  # tmp = stderr 
2>&1  # stderr = stdout
1>&3  # stdout = tmp
3>&-  # close(tmp)
```

init script '/dev/tty: No such device or address' error on redirect

Solution

Problem