peekfd

peekfd [-8,--eight-bit-clean] [-n,--no-headers] [-c,--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.

-8

Do no post-processing on the bytes being read or written.

-n

Do not display headers indicating the source of the bytes dumped.

-c

Also dump the requested file descriptor activity in any new child processes that are created.

-d

Remove duplicate read/writes from the output. If you're looking at a tty with echo, you might want this.

-v

Display a version string.

-h

Display a help message.

/proc/*/fd

Not used but useful for the user to look at to get good file descriptor numbers.

None.

The following diagnostics may be issued on stderr:

Error attaching to pid <PID>

An unknown error occurred while attempted to attach to a process, you may need to be root.

Probably lots. Don't be surprised if the process you are monitoring dies.

ttysnoop(8)

Trent Waddington