Check a TCP connection and response on raw BASH


Sometimes you don't have the proper tools to check connectivity to a site (curl, nc, ping) but you have a bash shell, so you can use bash built-in functions to do this.

exec 3<>/dev/tcp/127.0.0.1/8080 && echo -ne 'GET /index.html\n\n' >&3 && cat <&3 2>/dev/null