Usage is like:

$ ./pnetcat -h
Usage: ./pnetcat [-b blocksize_in_bytes] [-t total_bytes_to_transfer] [-i|-I port] [-o|-O hostname port|-n] [-w window] [-v]

-i              says to use file I/O to read from stdin
-I port         says to use sockets to get input from "port" on the local machine

-o              says to use file I/O to write to stdout
-O              hostname port   says to use sockets to connect to hostname on port
-n              says to only read - do not write the data anywhere (should be faster than writing to /dev/null)
-w size         says to set the TCP window size

--O-udp		Says to use UDP sockets, but only for the producer - IE modify -O mode
--I-udp		Says to use UDP sockets, but only for the consumer - IE modify -I mode
-u              Says to use UDP sockets, not the default, which is TCP (implies both of the above)

Naturally, -i conflicts with -I, and -o conflicts with -O

-w window conflicts with -u, because it's for setting the TCP window size

-N [0|1] says to set TCP_NODELAY to 0 or 1 (0 enables Nagel, 1 disables) (_N_agel Algorithm)

Also, -u of course requires -I or -O, --producer-udp requires -O and --consumer-tcp requires -I
Also note that -u may require small blocksizes compared to TCP
For example 65508 was once the highest UDP blocksize on a
run of the mill Fedora Core 4 system

Among -i/-I and -o/-O, the lower case letter does file I/O, and the capital does socket I/O
seki-strombrg:~/bin i386-redhat-linux-gnu 28661 - above cmd done Tue Apr 04 09:48 AM

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