Capture both stdout and stderr in Bash
bash, pipe, stderr, stdout, stream
Solution
There is no way to capture both without temp file.
You can capture stderr to variable and pass stdout to user screen (sample from here):
exec 3>&1 # Save the place that stdout (1) points to.
output=$(command 2>&1 1>&3) # Run command. stderr is captured.
exec 3>&- # Close FD #3.
# Or this alternative, which captures stderr, letting stdout through:
{ output=$(command 2>&1 1>&3-) ;} 3>&1
But there is no way to capture both stdout and stderr:
What you cannot do is capture stdout in one variable, and stderr in another, using only FD redirections. You must use a temporary file (or a named pipe) to achieve that one.
Problem
I know this syntax ``` var=`myscript.sh` ``` or ``` var=$(myscript.sh) ``` Will capture the result (`stdout`) of `myscript.sh` into `var`. I could redirect `stderr` into `stdout` if I wanted to capture both. How to save each of them to separate variables? My use case here is if the return code is nonzero I want to echo `stderr` and suppress otherwise. There may be other ways to do this but this approach seems it will work, if it's actually possible.