Name

clockadd — adjust the local UNIX clock, once

Synopsis

clockadd

Description

clockadd reads a TAI64NA time adjustment from standard input, as generated by a program such as taiclock(1) or sntpclock(1). It then adds that adjustment to the local UNIX clock.

Note

clockadd must be run by the superuser.

The adjustment must be a single 16-byte packet, readable in a single call to read(2). clockadd does not require that its standard input be a stream in blocking I/O mode.

The time is always "stepped" by calling settimeofday(2). clockadd does not call adjtime(2).

History

clockadd was originally part of Daniel J. Bernstein's clockspeed toolset in 1998.

Author

Original code and documentation by Daniel J. Bernstein. Documentation modernizations by Jonathan de Boyne Pollard.