bsdutils — Collection Overview

bsdutils is Debian packaging history you can hold in your hand: a small set of utilities whose ancestry is 4BSD but whose upstream home today is util-linux. Debian keeps them in their own binary package — installed on essentially every system, priority “required” — because boot-critical tooling depends on them. The collection covers the seven binaries the package ships; each page carries its own usage depth, and this hub holds the BSD-lineage story and the packaging logic.

Why a BSD-named Package on Linux

Early Linux distributions borrowed working userland from wherever it existed; the BSD-derived terminal and logging tools arrived as one bundle and kept the name through the 1990s packaging consolidation. Upstream, most of these tools migrated into util-linux during the 2010s (script, scriptreplay, renice, wall, logger), while write joined the absorbed bsdmainutils tools in bsdextrautils. The practical takeaway for interviews: package name, upstream project, and functional family are three different axes — logger is upstream util-linux, Debian package bsdutils, functionally part of the syslog toolchain.

Inventory

Note on the neighbors: the old bsdmainutils package was retired and its contents redistributed — col, hexdump, look, ul, column and friends now live in bsdextrautils and are covered in the util-linux collection. calendar and other true 4BSD relics left the default sets entirely.

Shared Concepts

• The terminal-permission triangle: write and wall both need the target’s mesg y permission; wall skips closed terminals and says so, write fails per-target. The mesg page in the util-linux collection holds the permission mechanics; the write and wall pages show the behavior.
• The script family: one recorder, two replay styles — timed playback (scriptreplay) and live re-execution (scriptlive). The pairing matters for demos, audit trails, and CI flake reproduction; the script page holds the timing-file format.
• System messaging: logger and wall are the two write paths into a system’s attention — the journal/syslog for machines, terminals for humans. Shutdown sequences chain both (wall the countdown, then logger the transition; /run/nologin gates new logins).
• Scheduling courtesy: renice is the scheduler-facing tool here; privilege rules (you may only make processes nicer) mirror the coreutils nice page and the procps snice variant.

Interview Questions

Q: You need an audit trail of everything typed in a support session. What do you reach for?

script -T timing -O typescript (or --log-timing/--log-io on modern util-linux) records the whole session with timing; scriptreplay plays it back for review. The gotchas interviewers probe: it records the terminal I/O, not the process tree (child ssh sessions are included because their I/O flows through the pty; but separate ttys are not), and passwords typed at prompts are captured too — audit convenience cuts against secret hygiene. See script for the file formats.

Q: Why does logger sometimes exit 0 without your message appearing?

Classic paths: no /dev/log socket in the namespace (a minimal container) and logger silently succeeds unless you ask for error reporting; or the message went to a facility your filter ignores. Check with logger --socket-errors=on, verify with journalctl -t, and pick explicit -p facility.priority — the logger page decodes the PRI computation.

Q: wall says “will not read /etc/nologin” in some invocations — what is going on?

util-linux wall has a shutdown-aware mode: when invoked by root with the right conditions it prints the nologin-file contents to logged-in users as part of the shutdown sequence. The broader point is the three-way split between broadcasting to current sessions (wall), gating new sessions (pam_nologin + /run/nologin), and messaging one user (write) — three tools, three questions. wall maps them.

References

• Source — Debian sources
• Source — GitHub (util-linux upstream)
• Man page index — manpages.debian.org