Here are several different ways to test a TCP port without telnet.
BASH (man page)
$ cat < /dev/tcp/127.0.0.1/22
SSH-2.0-OpenSSH_5.3
^C
$ cat < /dev/tcp/127.0.0.1/23
| import requests | |
| import json | |
| server = "https://ipam.ninux.org" | |
| appid = "appid" | |
| username = "username" | |
| password = "password" | |
| baseurl = server + "/api/" + appid |
Here are several different ways to test a TCP port without telnet.
$ cat < /dev/tcp/127.0.0.1/22
SSH-2.0-OpenSSH_5.3
^C
$ cat < /dev/tcp/127.0.0.1/23