Recover lost file from running process

I'm running a fairly long cli application and accidentally overwrote the output files. When the program starts, it prints out some information, and when it finishes, it writes out the data I need.

I'm trying to link the output file to a new location (which I would normally do under /proc/$pid/fd/1) but I can't find a way to do that on my mac.

I'm looking for any ideas on getting redirecting its output to a file again.