[Coelacanthus]

> This is a bash feature, not POSIX. dash (Debian’s /bin/sh) and zsh don’t have it, so a #!/bin/sh script can’t use it. Call bash directly.

Zsh has its own zsh/net/tcp and zsh/zftp modules.

https://zsh.sourceforge.io/Doc/Release/TCP-Function-System.h...

https://zsh.sourceforge.io/Doc/Release/Zsh-Modules.html#The-...

https://zsh.sourceforge.io/Doc/Release/Zftp-Function-System....