Redirection with dynamic fd allocation

[trchen1033]

brush version

brush 0.4.0

bash version (for comparison)

GNU bash, version 5.3.9(1)-release

Platform / OS

Linux

Steps to reproduce

{f}>&1 echo hello >&$f

Actual behavior (brush)

error: invalid redirection target

Expected behavior

hello

Additional context

As described in https://www.gnu.org/software/bash/manual/html_node/Redirections.html#Redirections

If {varname} were in place of a number before a redirection operator, bash find the next available fd >= 10 and store it in varname. Similarly, to close a dynamic fd, place {varname} before a close operator, i.e. {varname}>&-.

[reubeno]

Thanks for reporting this, @trchen1033. Dynamic FD allocation is not yet implemented in brush.

Contributions are definitely welcome to help us close this gap 😄.