lsclocks - Man Page

display system clocks

Synopsis

lsclocks [option]

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.

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

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

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).

ISO_TIME <string>

ISO8601 formatted version of TIME.

RESOL_RAW <number>

Clock resolution as returned by 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

Thomas Weißschuh

See Also

clock_getres(2) clock_gettime(2)

Reporting Bugs

For bug reports, use the issue tracker.

Availability

The lsclocks command is part of the util-linux package which can be downloaded from Linux Kernel Archive.

Info

2026-04-01 util-linux 2.42