nyan

Yet another netcat for fast file transfer

When I need to transfer a file in safe environment (e.g. LAN / VMs), I just want to use a simple command without cumbersome authentication, GUI, server etc. ncat usually works very well in this case. However, lastest ncat is super slow on Windows (~32KB/s), and that's why nyan was born. To my surprise, such a naive implementation works very well, even on linux.

Features

• Plain TCP stream
  • you don't need to use nyan at both end
• Progress indicator: Percentage, Size, ETA, Speed

Speed

Testing commands:

Linux ncat:
$ ncat -lvp 1234 --send-only < /dev/zero
$ ncat 127.0.0.1 1234 --recv-only | pv -perb > /dev/null

Linux nyan:
$ nyan send /dev/zero 1234
$ nyan recv /dev/null 1234 127.0.0.1

Windows:
$ zeros | ncat -lvp 1234 --send-only
$ ncat 127.0.0.1 1234 --recv-only > NUL

Windows nyan:
$ zeros | nyan send - 1234
$ nyan recv NUL 1234 127.0.0.1

Testing environment:

• Arch Linux host
• Windows 10 20H2 KVM guest with virtio netif connected to local bridge
• Arch Linux KVM guest with virtio netif connected to local bridge
• Ncat 5.59BETA1 on Windows performs better than latest version.

A	B	nyan (A->B)	ncat (A->B)	nyan (B->A)	ncat (B->A)
Linux Host	localhost	6.2 GB/s	2.6 GB/s	-	-
Linux VM	localhost	6.2 GB/s	1.9 GB/s	-	-
Windows VM	localhost	2.9 GB/s	0.6 GB/s	-	-
Linux Host	Linux VM	0.8 GB/s	0.7 GB/s	5.0 GB/s	2.2 GB/s
Linux Host	Windows VM	3.2 GB/s	1.2 GB/s	2.6 GB/s	0.3 GB/s
Linux VM	Windows VM	2.5 GB/s	0.8 GB/s	0.6 GB/s	0.3 GB/s