[niggler]

nc does this with the broadcast addresses (read https://en.wikipedia.org/wiki/Broadcast_address for more info):

Recipient listens on 0.0.0.0:

    recipient$ nc -l 0.0.0.0 6969 > file

Sender broadcasts to broadcast address:

    sender$ <file | nc 192.168.0.255 6969

or

    sender$ <file | nc 255.255.255.255 6969

[diginux]

1. In general, I am on the computer I want to send from, then I go to the computer I want to receive on. This script seems to require I be at the receiving computer first. Is there a trick to do it my way?

2. A very minor point, but you are still required to know (or at least specify) a the filename on the receiving end. My solution does not.

[niggler]

To solve both complaints, just tar -c on the ingress and tar -x on the egress:

    sender$ tar -c file | nc -l 12345
    recipient$ nc addr 12345 | tar -x

This will create a file on the recipient side with the specified name and properties (and you run the sender command first)

[diginux]

Doesn't seem to work for me

sender$ tar -c awesome.jpg | nc -l 0.0.0.0 12345

(waiting forever)

recipient$ nc 255.255.255.255 12345 | tar -x

tar: This does not look like a tar archive

tar: Exiting with failure status due to previous errors

[bluehex]

I'm not at a terminal now so can't verify this but it looks like you swapped the send and receive addresses from what was suggested. Try send on broadcast and receive on 0.0.0.0.