COMCONTROL(8)

📦
version 15.1 · 2 versions
, in freebsd 15.1

💅 COMCONTROL(8) — control a special tty device

okay so real talk first, bestie, before we get into anything: this is a System Manager's Manual page, section 8, and it's called comcontrol. cute name, iconic job. let's get into it 🎀

🚨 DEPRECATION NOTICE 🚨

Not me having to be the one to tell you this — the comcontrol utility is deprecated and will be removed in FreeBSD 16.0. so like... enjoy it while it lasts, but maybe don't build your whole personality around it. 😭

✨ SYNOPSIS ✨

comcontrol special_device [drainwait number]

that's the whole vibe. one device, one optional little extra. slay.

💖 DESCRIPTION 💖

so comcontrol is the tool you use to peek at and tweak some of the special characteristics of a tty device you point it at. lowkey a glow-up tool for terminals.

here's the tea on how it behaves:

  • if you give it no arguments other than the device itself, it prints out the settings of all controllable characteristics. a full vibe check, basically.
  • side note: you can also pass - instead of a device name to mean stdin. yes bestie, - is the classic "read from stdin" shortcut. we love a consistent queen.
  • this read-only usage needs only read access on the device. casual.
  • but if you want to change any settings? only the superuser can do that. root privileges required, no cap. 👑

🦋 OPTIONS 🦋

there's literally one option and she's doing her best:

  • drainwait number — sets the time to wait for output to drain to whatever number you give it. the units are seconds. the default is 5 minutes, and 0 means waiting forever (main character energy: no limits, no rules). this option is mainly there so you can set an upper limit in minutes and prevent your modem from hanging. 🫶

🌸 THE STANDARD WAY 🌸

the standard way to use comcontrol is to put invocations of it in the /etc/rc.d/serial startup script. that's the move. that's the whole strategy. iykyk.

🎀 FILES 🎀

  • /dev/ttyd? — dialin devices, hardwired terminals
  • /dev/cuau? — dialout devices

🌈 SEE ALSO 🌈

go read that one too, she's also iconic in her own way.

⭐ HISTORY ⭐

originally part of cgd's com package patches, version 0.2.1, to 386BSD 0.1. back in the day it once controlled bidirectional capabilities — very "we used to have it all" of it. but honestly? there's little left to control now, since those capabilities are standard. so she's kind of a retired diva at this point. 💀

👑 AUTHORS 👑

Christopher G. Demetriou

and that's the page, bestie!! this was COMCONTROL(8) from the Debian crew, dated August 31, 2025 — mwah, take care of her, she's deprecated 🫶✨

📦 where this page comes from