LSCLOCKS(1) User Commands LSCLOCKS(1)

# [NAME](#NAME)

lsclocks - display system clocks

# [SYNOPSIS](#SYNOPSIS)

**lsclocks** \[option]

# [DESCRIPTION](#DESCRIPTION)

**lsclocks** is a simple command to display system clocks.

It allows to display information like current time and resolution of clocks. Different kinds of clocks are supported.

•POSIX clocks: **CLOCK\_MONOTONIC**, **CLOCK\_REALTIME**, **CLOCK\_BOOTTIME**, etc.

•CPU clocks: [**clock\_getcpuclockid**(3)](/man/os/util-linux/clock_getcpuclockid.3).

•PTP clocks: **/dev/ptp0**.

•RTC clocks: **/dev/rtc0**.

•Auxiliary clocks: **CLOCK\_AUX0**, **CLOCK\_AUX1**, etc.

# [OPTIONS](#OPTIONS)

**-J**, **--json**

Use JSON output format.

**-n**, **--noheadings**

Don’t print headings.

**-o**, **--output** *list*

Specify which output columns to print. See the **OUTPUT COLUMNS** section for details of available columns.

**--output-all**

Output all columns.

**-r**, **--raw**

Use raw output format.

**-t**, **--time** *clock*

Show current time of one specific clock.

**--no-discover-dynamic**

Do not try to discover dynamic clocks.

**-d**, **--dynamic-clock** *path*

Also display specified dynamic clock. Can be specified multiple times.

**--no-discover-rtc**

Do not try to discover RTCs.

**-x**, **--rtc** *path*

Also display specified RTC. Can be specified multiple times.

**-c**, **--cpu-clock** *pid*

Also display CPU clock of specified process. Can be specified multiple times.

**-h**, **--help**

Display help text and exit.

**-V**, **--version**

Display version and exit.

# [ENVIRONMENT](#ENVIRONMENT)

LSCLOCKS\_COLUMNS=

Specifies a comma-separated list of output columns to print. All columns listed in **OUTPUT COLUMNS** can be used.

**LIBSMARTCOLS\_DEBUG**=all

enables libsmartcols debug output.

**LIBSMARTCOLS\_DEBUG\_PADDING**=on

use visible padding characters.

**LIBSMARTCOLS\_JSON**=compact|lines

Controls JSON output format when using **--json**. Supported values are **compact** for JSON output with minimal whitespace, and **lines** for JSON Lines format (one JSON object per line). If unset or set to any other value, pretty-printed JSON is used.

# [OUTPUT COLUMNS](#OUTPUT_COLUMNS)

Each column has a type. Types are surround by < and >.

TYPE <string>

Clock type.

ID <number>

Numeric clock ID.

CLOCK <string>

Name in the form **CLOCK\_**

NAME <string>

Shorter, easier to read name.

TIME <number>

Current clock timestamp as returned by [**clock\_gettime**(2)](/man/os/util-linux/clock_gettime.2).

ISO\_TIME <string>

ISO8601 formatted version of **TIME**.

RESOL\_RAW <number>

Clock resolution as returned by [**clock\_getres**(2)](/man/os/util-linux/clock_getres.2).

RESOL <number>

Human readable version of **RESOL\_RAW**.

REL\_TIME <string>

**TIME** time formatted as time range.

NS\_OFFSET <number>

Offset of the current namespace to the parent namespace as read from **/proc/self/timens\_offsets**.

# [AUTHORS](#AUTHORS)

*Thomas Weißschuh* <thomas@t-8ch.de>

# [SEE ALSO](#SEE_ALSO)

[**clock\_getres**(2)](/man/os/util-linux/clock_getres.2) [**clock\_gettime**(2)](/man/os/util-linux/clock_gettime.2)

# [REPORTING BUGS](#REPORTING_BUGS)

For bug reports, use the *issue tracker* <https://github.com/util-linux/util-linux/issues>.

# [AVAILABILITY](#AVAILABILITY)

The **lsclocks** command is part of the util-linux package which can be downloaded from *Linux Kernel Archive* <https://www.kernel.org/pub/linux/utils/util-linux/>.

2026-10-19 util-linux 2.42.4

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Document: lsclocks(1) from util-linux 2.42.4-r1 (Chainguard OS)