nspatch - run `nsdiff | nsupdate` with error handling
nspatch [-hVv] [-r count] -- [nsdiff options] -- [nsupdate options]
The nspatch utility runs `nsdiff | nsupdate` and checks that both programs complete successfully. It suppresses their output unless there is an error, in a manner suitable for running from cron.
The nsupdate script produced by nsdiff includes a prerequisite check to detect and fail if there is a concurrent update. These failures are detected by nspatch which retries the update.
Rather than using a pipe, nspatch uses temporary files to store the output of nsdiff and nsupdate.
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Display version information.
If the update fails because of a concurrent update, nspatch will retry up to count times. The default retry count is 2.
Turn on verbose mode, so the output from nsdiff and nsupdate is printed even if they are successful. (By default it is suppressed.)
The verbose option is passed on to nsdiff. If nspatch is not given the -v option, it passes the -v '' option to nsdiff. If nspatch is given the -v option, it passes the -v 'qr' option to nsdiff.
The nspatch utility returns 0 if no change is required or if the update is successful, or 1 if there is an error.
TMPDIRLocation for temporary files.
This is nspatch-1.85 <https://dotat.at/prog/nsdiff/>
Written by Tony Finch <fanf2@cam.ac.uk> <dot@dotat.at>
at Cambridge University Information Services.
You may do anything with this. It has no warranty.nsdiff(1), nsupdate(1), cron(8)