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'\" t
.\" Title: lsclocks
.\" Author: [see the "AUTHOR(S)" section]
.\" Generator: Asciidoctor 2.0.20
.\" Date: 2026-02-18
.\" Manual: User Commands
.\" Source: util-linux 2.42-rc1
.\" Language: English
.\"
.TH "LSCLOCKS" "1" "2026-02-18" "util\-linux 2.42\-rc1" "User Commands"
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.\}
.SH "NAME"
lsclocks \- display system clocks
.SH "SYNOPSIS"
.sp
\fBlsclocks\fP [option]
.SH "DESCRIPTION"
.sp
\fBlsclocks\fP is a simple command to display system clocks.
.sp
It allows to display information like current time and resolution of clocks.
Different kinds of clocks are supported.
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
. sp -1
. IP \(bu 2.3
.\}
POSIX clocks: \fBCLOCK_MONOTONIC\fP, \fBCLOCK_REALTIME\fP, \fBCLOCK_BOOTTIME\fP, etc.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
. sp -1
. IP \(bu 2.3
.\}
CPU clocks: \fBclock_getcpuclockid\fP(3).
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
. sp -1
. IP \(bu 2.3
.\}
PTP clocks: \fB/dev/ptp0\fP.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
. sp -1
. IP \(bu 2.3
.\}
RTC clocks: \fB/dev/rtc0\fP.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
. sp -1
. IP \(bu 2.3
.\}
Auxiliary clocks: \fBCLOCK_AUX0\fP, \fBCLOCK_AUX1\fP, etc.
.RE
.SH "OPTIONS"
.sp
\fB\-J\fP, \fB\-\-json\fP
.RS 4
Use JSON output format.
.RE
.sp
\fB\-n\fP, \fB\-\-noheadings\fP
.RS 4
Don\(cqt print headings.
.RE
.sp
\fB\-o\fP, \fB\-\-output\fP \fIlist\fP
.RS 4
Specify which output columns to print. See the \fBOUTPUT COLUMNS\fP
section for details of available columns.
.RE
.sp
\fB\-\-output\-all\fP
.RS 4
Output all columns.
.RE
.sp
\fB\-r\fP, \fB\-\-raw\fP
.RS 4
Use raw output format.
.RE
.sp
\fB\-t\fP, \fB\-\-time\fP \fIclock\fP
.RS 4
Show current time of one specific clock.
.RE
.sp
\fB\-\-no\-discover\-dynamic\fP
.RS 4
Do not try to discover dynamic clocks.
.RE
.sp
\fB\-d\fP, \fB\-\-dynamic\-clock\fP \fIpath\fP
.RS 4
Also display specified dynamic clock.
Can be specified multiple times.
.RE
.sp
\fB\-\-no\-discover\-rtc\fP
.RS 4
Do not try to discover RTCs.
.RE
.sp
\fB\-x\fP, \fB\-\-rtc\fP \fIpath\fP
.RS 4
Also display specified RTC.
Can be specified multiple times.
.RE
.sp
\fB\-c\fP, \fB\-\-cpu\-clock\fP \fIpid\fP
.RS 4
Also display CPU clock of specified process.
Can be specified multiple times.
.RE
.SH "ENVIRONMENT"
.sp
LSCLOCKS_COLUMNS=
.RS 4
Specifies a comma\-separated list of output columns to print. All columns listed in \fBOUTPUT COLUMNS\fP can be used.
.RE
.sp
\fB\-h\fP, \fB\-\-help\fP
.RS 4
Display help text and exit.
.RE
.sp
\fB\-V\fP, \fB\-\-version\fP
.RS 4
Display version and exit.
.RE
.SH "OUTPUT COLUMNS"
.sp
Each column has a type. Types are surround by < and >.
.sp
TYPE <\f(CRstring\fP>
.RS 4
Clock type.
.RE
.sp
ID <\f(CRnumber\fP>
.RS 4
Numeric clock ID.
.RE
.sp
CLOCK <\f(CRstring\fP>
.RS 4
Name in the form \fBCLOCK_\fP
.RE
.sp
NAME <\f(CRstring\fP>
.RS 4
Shorter, easier to read name.
.RE
.sp
TIME <\f(CRnumber\fP>
.RS 4
Current clock timestamp as returned by \fBclock_gettime\fP(2).
.RE
.sp
ISO_TIME <\f(CRstring\fP>
.RS 4
ISO8601 formatted version of \fBTIME\fP.
.RE
.sp
RESOL_RAW <\f(CRnumber\fP>
.RS 4
Clock resolution as returned by \fBclock_getres\fP(2).
.RE
.sp
RESOL <\f(CRnumber\fP>
.RS 4
Human readable version of \fBRESOL_RAW\fP.
.RE
.sp
REL_TIME <\f(CRstring\fP>
.RS 4
\fBTIME\fP time formatted as time range.
.RE
.sp
NS_OFFSET <\f(CRnumber\fP>
.RS 4
Offset of the current namespace to the parent namespace as read from \fB/proc/self/timens_offsets\fP.
.RE
.SH "AUTHORS"
.sp
.MTO "thomas\(att\-8ch.de" "Thomas Weißschuh" ""
.SH "SEE ALSO"
.sp
\fBclock_getres\fP(2) \fBclock_gettime\fP(2)
.SH "REPORTING BUGS"
.sp
For bug reports, use the \c
.URL "https://github.com/util\-linux/util\-linux/issues" "issue tracker" "."
.SH "AVAILABILITY"
.sp
The \fBlsclocks\fP command is part of the util\-linux package which can be downloaded from \c
.URL "https://www.kernel.org/pub/linux/utils/util\-linux/" "Linux Kernel Archive" "."
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