(or "In dash, ... is not supported." when using
echo foo > /dev/tcp/myhost/1234
Rewrite using a tool like netcat (
echo foo | nc myhost 1234
/dev/udp/$host/$port are recognized in redirections by bash and ksh, and a socket connection is made instead of opening a file. They do not physically exist in
POSIX sh and dash do not support this, so any such code should be rewritten to use a socket tool explicitly. The obvious candidate is netcat aka
ShellCheck is a static analysis tool for shell scripts. This page is part of its documentation.