tcp

tcp tests whether a host and port accept a TCP connection and can optionally establish and inspect a verified TLS session.

NetworkVersion 1.2.2Stable
lil-terminal

Overview

Use tcp for TCP ports and TLS connections. Common operations stay short; specialized forms add detail only when needed, so repeated work remains easy to understand, repeat and place in lil-terminal scripts.

Test the port first, then TLS

A plain probe answers whether TCP can connect. -tls adds certificate verification, -i shows protocol, cipher and certificate details, and -k deliberately removes the trust check so you can distinguish a certificate problem from basic connectivity.

Syntax

lil-terminal
tcp <host|ip|me> <port> [options]

Reference

tcp me 443

use the current host

tcp example.com 443

test a TCP port

tcp example.com 443 -tls

open a verified TLS connection

tcp example.com 443 -tls -i

show TLS protocol, cipher and certificate details

tcp example.com 443 -tls -k

allow an insecure TLS certificate

-t [seconds]

use 5 seconds (or a timeout from 1 to 300)

-T

use a 300-second timeout

-4 | -6

use IPv4 or IPv6

-tls

enable TLS with certificate verification

-i

show TLS connection and certificate details

-k

allow an insecure TLS certificate (requires -tls)

Interactive sandbox preview

Run the prepared examples directly on the page. Their results are prebuilt and shown in the browser; no terminal command is executed on the server.

Check the port, then inspect TLS

Install and manage

Install the current compatible version. Choose Base for the complete feature set or Minimum for the reduced package; use upgrade to update a module that is already installed.

Base and Minimum are two packages of the same current module release, not separate command versions.

Base package

Install the complete package with local command reference and every published mode.

install tcp
Minimum package

Install the reduced package. Local reference is omitted; help <cmd> -i opens the current server reference.

install tcp -m
Exact public version

Install exactly this published version.

install tcp -v 1.2.2
Check or update

Ask upgrade to check compatibility and replace the installed block only when needed.

upgrade tcp
Remove module

Remove the extension block while leaving the core and unrelated modules intact.

install tcp -u

Examples

Examples are copyable command lines, not actions executed by this website. Review paths, permissions and destructive flags before running them on a real project.

Check the port, then inspect TLS
tcp example.com 443 | tcp example.com 443 -tls -i
Host      example.com
IP        93.184.216.34
Port      443
Protocol  TCP
Status    open
Time      18.4 ms

Host      example.com
IP        93.184.216.34
Port      443
Protocol  TLS
Status    open
Time      22.1 ms
TLS       TLSv1.3
Cipher    TLS_AES_256_GCM_SHA384
Bits      256
Issuer    Example CA
Open a verified TLS connection
tcp example.com 443 -tls
Host      example.com
IP        93.184.216.34
Port      443
Protocol  TLS
Status    open
Time      22.1 ms
Show TLS protocol, cipher and certificate details
tcp example.com 443 -tls -i
Host        example.com
IP          93.184.216.34
Port        443
Protocol    TLS
Status      open
Time        22.1 ms
TLS         TLSv1.3
Cipher      TLS_AES_256_GCM_SHA384
Bits        256
Subject     CN=example.com
Issuer      Example CA
Valid from  2026-01-01 00:00:00 UTC
Valid to    2027-01-01 00:00:00 UTC
Use IPv4 or IPv6
tcp example.com 443 -4
Host      example.com
IP        93.184.216.34
Port      443
Protocol  TCP
Status    open
Time      18.4 ms
Use 5 seconds (or a timeout from 1 to 300)
tcp example.com 443 -t 2
Host      example.com
IP        93.184.216.34
Port      443
Protocol  TCP
Status    open
Time      18.4 ms
Allow an insecure TLS certificate (requires -tls)
tcp example.com 443 -tls -k
Host      example.com
IP        93.184.216.34
Port      443
Protocol  TLS
Status    open
Time      22.1 ms
Reject an invalid port
tcp example.com 70000
Invalid port

Related documentation

What network diagnostics are available? →What if repo.lil.dog is unavailable? →

Current public release

v1.2.22026-08-10

Current host first

Moves tcp me 443 to the first practical example.

# Version history