We have a requirement to troubleshoot an existing system running Busybox, we have Telnet access. It would be helpful to log the system's console output (ideally the last n lines of it) to a file for debugging.
There's plenty of examples on redirecting the stdout/stderr of a command to a file at the point of invocation, but I can't find anything conclusive on capturing output from a running process or processes.
It seems like we should perhaps be able to capture/redirect from
/proc/<PID>/fd/1 but searching suggests this is not possible, and I haven't managed to find an incantation to make it work.
Being a small embedded system we can't install more packages, so if it can't be done with basic command-line kung-fu we'll have to go back to the drawing board.