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Diffstat (limited to 'sys-utils/clock.8')
| -rw-r--r-- | sys-utils/clock.8 | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/sys-utils/clock.8 b/sys-utils/clock.8 new file mode 100644 index 000000000..f4dd83ade --- /dev/null +++ b/sys-utils/clock.8 @@ -0,0 +1,108 @@ +.\" Copyright 1992 Rickard E. Faith (faith@cs.unc.edu) +.\" May be distributed under the GNU General Public License +.TH CLOCK 8 "24 December 1992" "Linux 0.99" "Linux Programmer's Manual" +.SH NAME +clock \- manipulate the CMOS clock +.SH SYNOPSIS +.B "/etc/clock [ -u ] -r" +.br +.B "/etc/clock [ -u ] -w" +.br +.B "/etc/clock [ -u ] -s" +.br +.B "/etc/clock [ -u ] -a" +.SH DESCRIPTION +.B clock +manipulates the CMOS clock in variaous ways, allowing it to be read or +written, and allowing synchronization between the CMOS clock and the +kernel's version of the system time. +.SH OPTIONS +.TP +.B \-u +Indicates that the CMOS clock is set to Universal Time. +.TP +.B \-r +Read CMOS clock and print the result to stdout. +.TP +.B \-w +Write the system time into the CMOS clock. +.TP +.B \-s +Set the system time from the CMOS clock. +.TP +.B \-a +Set the system time from the CMOS clock, adjusting the time to correct for +systematic error, and writting it back into the CMOS clock. +.sp +This option uses the file +.I /etc/adjtime +to determine how the clock changes. It contains three numbers: +.RS +The first number is the correction in seconds per day (for example, if your +clock runs 5 seconds fast each day, the first number should read -5.0). +.LP +The second number tells when +.B clock +was last used, in seconds since 1/1/1970. +.LP +The third number is the remaining part of a second that was left over after +the last adjustment. +.LP +The following instructions are from the source code: +.TP +a) +create a file +.I /etc/adjtime +containing as the first and only line: '0.0 0 0.0' +.TP +b) +run +.I "clock -au" +or +.IR "clock -a" , +depending on whether your CMOS is in Universal or Local Time. This updates +the second number. +.TP +c) +set your system time using the +.I date +command. +.TP +d) +update your CMOS time using +.I "clock -wu" +or +.I clock -w +.TP +e) +replace the first number in +.I /etc/adjtime +by your correction. +.TP +f) +put the command +.I "clock -au" +or +.I "clock -a" +in your +.IR /etc/rc.local , +or let +.BR cron (8) +start it regularly. +.RE +.SH FILES +.I /etc/adjtime +.br +.I /etc/rc.local +.SH AUTHORS +.TP +.B V1.0 +Charles Hedrick, hedrick@cs.rutgers.edu, Apr 1992 +.TP +.B V1.1 +Modified for clock adjustments, Rob Hooft, hooft@chem.ruu.nl, Nov 1992 +.TP +.B V1.2 +Patches by Harald Koenig, koenig@nova.tat.physik.uni-tuebingen.de, +applied by Rob Hooft, hooft@EMBL-Heidelberg.DE, Oct 1993 +.sp |