I tried basically exactly that, and it didn't work for me. On my test system (Ubuntu 21.10 on x86_64) the puts() call never fails. I switched to a raw write()

I tried basically exactly that, and it didn't work for me. On my test system (Ubuntu 21.10 on x86_64) the puts() call never fails. I switched to a raw write() and that successfully catches it, by returning -1 when output is redirected to /dev/full. Quite interesting, actually.