PT(4)

📦 version 12.2, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

✨ PT(4) — the SCSI processor type driver, bestie edition ✨

okay so. this is pt(4), like, section 4 of the manual, from the Kernel Interfaces Manual — and she's the SCSI processor type driver. yes she's niche. yes she's iconic. let's get into it 💅

🌸 NAME 🌸

pt — the SCSI processor type driver. that's her. that's the whole name. no notes.

🎀 SYNOPSIS 🎀

device pt

literally that's it. one line. she's low-maintenance. slay.

💖 DESCRIPTION 💖

okay so the pt driver is the one that provides support for a SCSI processor type device. and what even is a SCSI processor type device, you ask? bestie, it's usually scanners and other devices that use the SCSI link as a communication interface, with device specific commands just vibing there embedded in the data stream. like, the device has its own little language and the driver just passes it along. iykyk 🦋

important!! a SCSI adapter must be separately configured into the system before this driver can even be used. so no, you can't just show up with device pt and expect the whole thing to work. the adapter is doing the heavy lifting. main character energy tbh.

and the tea on what she supports: this device supports read(2) and write(2), plus the ioctl(2) calls we're about to get into down below. three whole system calls. she's versatile. periodt ✨

🔥 IOCTLS 🔥

here's the part where it gets juicy. the following ioctl(2) calls are supported by the pt driver, and they're defined in the header file <sys/ptio.h>. memorize that path, you'll need it.

  • PTIOCGETTIMEOUT — this one lets userland applications fetch the current pt driver read and write timeout. and the value that comes back to you? it's in seconds. cute, simple, no surprises. 🎀
  • PTIOCSETTIMEOUT — and this one lets userland applications set the current pt driver read and write timeouts. the value you hand over should be in seconds too. matching set, love that for them. 🫶

🌈 FILES 🌈

  • /dev/ptN — the Nth processor device. the N is the number, bestie. swap it for whichever one you actually want. that's the whole vibe.

👑 SEE ALSO 👑

just the one. she keeps her circle small. respect. 💜

🦋 HISTORY 🦋

the pt driver appeared in FreeBSD 2.1. an elder. a legend. we stan a driver with lore. ⭐

and that's the whole page!! 💖 this one came to you from Debian, dated March 2, 1995, and it lives in the manual as PT(4). no cap, she's been here a while and she's still doing her thing. mwah 🎀💅✨
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