LTTNG-HELP(1)

📦
version 2.15.1 · 12 versions
, in ubuntu stonking

💖 LTTNG-HELP(1) — the LTTng Manual, bestie edition 💖

okay so this is lttng-help, part of the LTTng Manual, and it's genuinely so simple it's iconic. sit down, grab a strawberry 🍓, and let's get into it.

🌸 NAME 🌸

lttng-help — show the help of an LTTng command

✨ SYNOPSIS ✨

lttng [GENERAL OPTIONS] help [COMMAND]

🦋 DESCRIPTION 🦋

The lttng help command shows the help of... bestie, it depends 💅:

  • With the COMMAND argument — it shows the help of the lttng COMMAND command.
  • Without the COMMAND argument — it shows the help of the lttng(1) command itself.

no cap, the help command is literally equivalent to this:

lttng [GENERAL OPTIONS] [COMMAND] --help

So it's giving "same energy, different font." 💅

The help command attempts to launch /usr/bin/man to view the manual page of the command. Wanna override the manual pager path? That's what the LTTNG_MAN_BIN_PATH environment variable is for, periodt 🌈

🎀 OPTIONS 🎀

See lttng(1) for GENERAL OPTIONS.

🌟 Program information 🌟

  • -h, --help — show help.

This option attempts to launch /usr/bin/man to view this manual page. Override the manual pager path with the LTTNG_MAN_BIN_PATH environment variable.

  • --list-options — list available command options and quit. bye 👋

💀 EXIT STATUS 💀

  • 0 — success 🎉 (ate, no crumbs)
  • 1 — command error 😭
  • 2 — undefined command 🙈
  • 3 — fatal error 💀
  • 4 — command warning (something went wrong during the command) 🫠

🌈 ENVIRONMENT 🌈

  • LTTNG_ABORT_ON_ERROR — set to 1 to abort the process after the first error is encountered.
  • LTTNG_HOME — path to the LTTng home directory.

Defaults to $HOME.

Lowkey useful when the Unix user running the commands has a non-writable home directory 👑

  • LTTNG_LIST_LEGACY — set to 1 to use the legacy output format (LTTng 2.14 and earlier) for the lttng-list(1) command instead of the modern output format.

Note that the legacy output doesn't show anything related to features introduced after LTTng 2.14. it's giving throwback, but the throwback is missing things, so be aware 🕰️

  • LTTNG_MAN_BIN_PATH — absolute path to the manual pager to use to read the LTTng command-line help (with lttng-help(1) or with the --help option) instead of /usr/bin/man.
  • LTTNG_NO_UTF_8 — set to 1 to NOT emit multi-byte UTF-8 sequences, even if the locale claims to support it.
  • LTTNG_SESSION_CONFIG_XSD_PATH — path to the directory containing the session.xsd recording session configuration XML schema.
  • LTTNG_SESSIOND_PATH — absolute path to the LTTng session daemon binary (see lttng-sessiond(8)) to spawn from the lttng-create(1) command.

The --sessiond-path general option overrides this environment variable. yes, the option wins, no debate 🫶

  • LTTNG_TERM_COLOR — controls when to emit terminal SGR codes in the output.

The NO_COLOR environment variable overrides this. 🚨

One of:

  • auto (default) — only emit SGR codes when the standard output is connected to a color-capable terminal.
  • always — always emit SGR codes. rainbow mode on, permanently 🌈
  • never — never emit SGR codes. monochrome era 💀
  • NO_COLOR — if set and not empty, then it's equivalent to setting LTTNG_TERM_COLOR to never.

See NO_COLOR <https://no-color.org/> to learn more.

🧚 FILES 🧚

  • $LTTNG_HOME/.lttngrc — Unix user's LTTng runtime configuration.

This is where LTTng stores the name of the Unix user's current recording session between executions of lttng(1). lttng-create(1) and lttng-set-session(1) set the current recording session.

  • $LTTNG_HOME/lttng-traces — default output directory of LTTng traces in local and snapshot modes.

Override this path with the --output option of the lttng-create(1) command.

  • $LTTNG_HOME/.lttng — Unix user's LTTng runtime and configuration directory.
  • $LTTNG_HOME/.lttng/sessions — default directory containing the Unix user's saved recording session configurations (see lttng-save(1) and lttng-load(1)).
  • /etc/lttng/sessions — directory containing the system-wide saved recording session configurations (see lttng-save(1) and lttng-load(1)).
Note 📌 $LTTNG_HOME defaults to the value of the HOME environment variable.

🔥 RESOURCES 🔥

This program is part of the LTTng-tools project.

LTTng-tools is distributed under the GNU General Public License version 2 http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html. See the LICENSE https://github.com/lttng/lttng-tools/blob/master/LICENSE file for details.

💜 THANKS 💜

Special thanks to Michel Dagenais and the DORSAL laboratory http://www.dorsal.polymtl.ca/ at École Polytechnique de Montréal for the LTTng journey. 🫶

Also thanks to the Ericsson teams working on tracing which helped us greatly with detailed bug reports and unusual test cases. the bug reports ate, fr fr 🐛✨

⭐ SEE ALSO ⭐

lttng(1)

and that's the whole vibe check bestie — this little page is from LTTng 2.15.1, dated 21 April 2021. stay slaying, go read your man pages 💖🎀🦋

📦 where this page comes from