peekfd [-8,--eight-bit-clean] [-n,--no-headers] [-f,--follow] [-d,--duplicates-removed] [-V,--version] [-h,--help] pid [fd] [fd] ...
peekfd attaches to a running process and intercepts all reads and writes to file descriptors. You can specify the desired file descriptor numbers or dump all of them.
The following diagnostics may be issued on stderr:
Probably lots. Don't be surprised if the process you are monitoring dies.