macOS
Homebrewverified · 100%
brew install ucspi-tcplocal Homebrew formula metadata
MacPortsverified · 94%
sudo port install ucspi-tcpMacPorts ports tree · net/ucspi-tcp/Portfile · source: api.github.com
brew
Install ucspi-tcp with Homebrew, apt, MacPorts, Nix, apk, dnf
Tools for building TCP client-server applications. Version 0.88 via Homebrew; verified from local package data.
install
Additional install commands
Linux
Debian aptverified · 92%
sudo apt install ucspi-tcpDebian stable package indexes · ucspi-tcp · source: deb.debian.org
Nixverified · 92%
nix profile install nixpkgs#ucspi-tcpnixpkgs package indexes · pkgs/by-name/uc/ucspi-tcp/package.nix · source: api.github.com
Alpine Linux apkverified · 92%
sudo apk add dateAlpine Linux edge package indexes · date · source: dl-cdn.alpinelinux.org
Fedora dnfverified · 92%
sudo dnf install date-develFedora Rawhide package metadata · date-devel · source: dl.fedoraproject.org
overview
Package summary
Tools for building TCP client-server applications
Project links
Commands and aliases
- addcr
- argv0
- date@
- delcr
- finger@
- fixcrio
- http@
- mconnect
- mconnect-io
- rblsmtpd
- recordio
- tcpcat
- tcpclient
- tcprules
- tcprulescheck
- tcpserver
- who@
history
Project history and usage
ucspi-tcp is Daniel J. Bernstein's Unix Client-Server Program Interface implementation for TCP. It provides small command-line tools such as tcpserver and tcpclient for building TCP services and clients around ordinary Unix programs.
Project history
The UCSPI specification is dated 1996 and defines a command-line interface for client-server communication tools. ucspi-tcp applies that model to TCP, with clients and servers setting descriptors and environment variables before executing an application.
The official install page identifies ucspi-tcp 0.88 as the latest published package, and the official tarball has a March 18, 2000 last-modified date. The project is distributed from Bernstein's cr.yp.to site rather than through a public source-control repository.
Adoption history
ucspi-tcp became part of the classic djb software ecosystem, especially alongside daemontools-style service supervision and qmail-era mail setups. The input package metadata shows that, despite its age and tarball distribution model, it remains packaged in Homebrew, Debian, Ubuntu, MacPorts, Nix, and other Unix package collections.
How it is used
Package users most often encounter tcpserver, tcpclient, tcprules, tcprulescheck, recordio, rblsmtpd, and helper tools. The official docs describe tcpserver as a way to accept TCP connections and run another program, while rblsmtpd is documented as an SMTP wrapper that blocks mail from listed sites when used under tcpserver.
Why package nerds care
For package nerds, ucspi-tcp is historically significant because it is a compact Unix networking toolkit from the pre-systemd, pre-framework era. It represents a style where small binaries, environment variables, file-descriptor conventions, and package-manager preservation keep old but sharp infrastructure tools available.
Timeline
- 1996: UCSPI specification copyrighted by D. J. Bernstein.
- 2000: ucspi-tcp 0.88 tarball published according to official HTTP metadata.
- 2002: rblsmtpd documentation records then-current public RBL source status updates.
- Current packaging: source_facts lists Homebrew, Debian, Ubuntu, MacPorts, Nix, and other package-manager entries.
Related projects
- The official rblsmtpd page points to tcpserver and tcprules as companion programs within the suite.
- The documentation also points to rbldns from djbdns for running RBL or anti-RBL sources.
Sources
security posture
Risk level: blue
broad file, network, media, or database tool signal.
Risk classifier
blue risk · medium confidence · tool
Why
- broad file, network, media, or database tool signal
Signals
- text:http,record,client,server
Install behavior
- No Homebrew post-install hook is recorded in formula metadata.
- Homebrew bottle metadata is available for 13 platform targets.
Recommended review
Before unattended agent use, check whether the tool reads plaintext credentials, writes remote state, publishes artifacts, or shells out to plugins.
executables
Installed executables
| Command | Kind | Exposure | Note |
|---|---|---|---|
addcr | cli | global executable | |
argv0 | cli | global executable | |
date@ | cli | global executable | |
delcr | cli | global executable | |
finger@ | cli | global executable | |
fixcrio | cli | global executable | |
http@ | cli | global executable | |
mconnect | cli | global executable | |
mconnect-io | cli | global executable | |
rblsmtpd | cli | global executable | |
recordio | cli | global executable | |
tcpcat | cli | global executable | |
tcpclient | cli | global executable | |
tcprules | cli | global executable | |
tcprulescheck | cli | global executable | |
tcpserver | cli | global executable | |
who@ | cli | global executable |
freshness
Version and freshness
These signals separate page generation age, package-manager activity, and upstream release comparison. Version lag is warned only when an evidence URL and comparable versions are present.
page generated2026-07-08
manager version0.88
manager updated
local dataok
upstreamnot checked
latest detectednot detected
https://cr.yp.to/ucspi-tcp.html
- infoNo package-manager update timestamp was available.low confidence
- infoRelease/tag comparison is only available for GitHub repositories.https://cr.yp.to/ucspi-tcp.htmlnone confidence
install metadata
Package metadata
| Package key | brew:ucspi-tcp |
|---|---|
| Version | 0.88 |
| Package manager | Homebrew |
| Package manager page | https://formulae.brew.sh/formula/ucspi-tcp |
| Homepage | https://cr.yp.to/ucspi-tcp.html |
| Upstream docs | https://cr.yp.to/ucspi-tcp.html |
| License | LicenseRef-Homebrew-public-domain |
| Source archive | https://cr.yp.to/ucspi-tcp/ucspi-tcp-0.88.tar.gz |
| Bottle | available (on arm64_big_sur, arm64_linux, arm64_monterey, arm64_sequoia, arm64_sonoma, arm64_tahoe, arm64_ventura, big_sur, catalina, monterey, sonoma, ventura, x86_64_linux) |
| Homebrew post-install | not defined |
| Service | none declared |
registry facts
Source database details
| Source Database | Homebrew formula API |
|---|---|
| Tap | homebrew/core |
| Full Name | ucspi-tcp |
| Version Scheme | 0 |
| Revision | 0 |
| Bottle Stable Root URL | https://ghcr.io/v2/homebrew/core |
| Deprecated | no |
| Disabled | no |
| Keg Only | no |
| URL Keys |
|
source database matches
Other package-manager records
Matches are pulled from external package-manager indexes and kept separate from local Automic Vault package links.
Debian apt95%
ucspi-tcp 1:0.88-13
command-line tools for building TCP client-server applications
sudo apt install ucspi-tcp- Section: net
- Architecture: amd64
- 1 dependencies
- normalized package name match
- Matched by: Ucspi Tcp
Debian apt95%
ucspi-tcp-ipv6 1:0.88-13
command-line tools for building TCP client-server applications (IPv6)
sudo apt install ucspi-tcp-ipv6- Section: net
- Architecture: amd64
- Source Package: ucspi-tcp
- 1 dependencies
- 1 provides
- normalized package name match
- Matched by: Ucspi Tcp
Nix95%
ucspi-tcp
nix profile install nixpkgs#ucspi-tcp- normalized package name match
- Matched by: Ucspi Tcp
Ubuntu apt95%
ucspi-tcp 1:0.88-8ubuntu1
command-line tools for building TCP client-server applications
sudo apt install ucspi-tcp- Section: universe/net
- Architecture: amd64
- 1 dependencies
- normalized package name match
- Matched by: Ucspi Tcp
Ubuntu apt95%
ucspi-tcp-ipv6 1:0.88-8ubuntu1
command-line tools for building TCP client-server applications (IPv6)
sudo apt install ucspi-tcp-ipv6- Section: universe/net
- Architecture: amd64
- Source Package: ucspi-tcp
- 1 dependencies
- 1 provides
- normalized package name match
- Matched by: Ucspi Tcp
MacPorts95%
ucspi-tcp
sudo port install ucspi-tcp- normalized package name match
- Matched by: Ucspi Tcp
Debian apt92%
finger 0.17-17
user information lookup program
http://ftp.linux.org.uk/pub/linux/Networking/netkit/
sudo apt install finger- Section: net
- Architecture: amd64
- Source Package: bsd-finger
- 1 dependencies
- installed executable or alias match
- Matched by: Finger
Debian apt92%
r-cran-date 1.2.42-1
GNU R package for date handling
https://cran.r-project.org/package=date
sudo apt install r-cran-date- Section: gnu-r
- Architecture: amd64
- Source Package: date
- 3 dependencies
- installed executable or alias match
- Matched by: Date
Ubuntu apt92%
finger 0.17-17
user information lookup program
http://ftp.linux.org.uk/pub/linux/Networking/netkit/
sudo apt install finger- Section: universe/net
- Architecture: amd64
- Source Package: bsd-finger
- 1 dependencies
- installed executable or alias match
- Matched by: Finger
Ubuntu apt92%
r-cran-date 1.2.42-1
GNU R package for date handling
https://cran.r-project.org/package=date
sudo apt install r-cran-date- Section: universe/math
- Architecture: amd64
- Source Package: date
- 3 dependencies
- installed executable or alias match
- Matched by: Date
apk92%
date 3.0.4-r0
Date and time library based on the C++11/14/17 <chrono> header
https://howardhinnant.github.io/date/date.html
sudo apk add date- License: MIT
- Architecture: x86_64
- Source Package: date
- 1 dependencies
- 1 provides
- installed executable or alias match
- Matched by: Date
apk92%
date-dev 3.0.4-r0
Date and time library based on the C++11/14/17 <chrono> header (development files)
https://howardhinnant.github.io/date/date.html
sudo apk add date-dev- License: MIT
- Architecture: x86_64
- Source Package: date
- 1 dependencies
- 1 provides
- installed executable or alias match
- Matched by: Date
apk92%
finger 0.5-r0
Small, simple, and portable finger client and server
sudo apk add finger- License: MIT
- Architecture: x86_64
- Source Package: finger
- 1 dependencies
- 1 provides
- installed executable or alias match
- Matched by: Finger
apk92%
finger-doc 0.5-r0
Small, simple, and portable finger client and server (documentation)
sudo apk add finger-doc- License: MIT
- Architecture: x86_64
- Source Package: finger
- installed executable or alias match
- Matched by: Finger
dnf92%
date-devel 3.0.4-3.fc44
Date and time library based on the C++11/14/17 <chrono> header
https://github.com/HowardHinnant/date
sudo dnf install date-devel- License: MIT
- Category: Unspecified
- Architecture: i686
- Source Package: date
- 4 dependencies
- 4 provides
- installed executable or alias match
- Matched by: Date
dnf92%
finger 0.17-83.fc44
The finger client
sudo dnf install finger- License: BSD-4-Clause-UC
- Category: Unspecified
- Architecture: x86_64
- Source Package: finger
- 2 dependencies
- 1 provides
- installed executable or alias match
- Matched by: Finger
source trail
Generated from repository data
This page is generated by av-web from the private package SQLite artifact built by scripts/generate-pkg-sqlite.py.
Combined YAML source
View the package source record on GitHub.
Used sources
- Geiger risk classifier
- Nucleus package database
- av.db category and tag curation
- cross-ecosystem install command graph
- curated package history
- external package-manager database matches
- package relationship graph
- package version freshness
- package-page enrichment