*utmpdump* is a simple program to dump UTMP and WTMP files in raw format, so they can be examined. *utmpdump* reads from stdin unless a _filename_ is passed.
*utmpdump* can be useful in cases of corrupted utmp or wtmp entries. It can dump out utmp/wtmp to an ASCII file, which can then be edited to remove bogus entries, and reintegrated using:
____
*utmpdump -r < ascii_file > wtmp*
____
But be warned, *utmpdump* was written for debugging purposes only.
=== File formats
Only the binary version of the *utmp*(5) is standardised. Textual dumps may become incompatible in future.
The version 2.28 was the last one that printed text output using *ctime*(3) timestamp format. Newer dumps use millisecond precision ISO-8601 timestamp format in UTC-0 timezone. Conversion from former timestamp format can be made to binary, although attempt to do so can lead the timestamps to drift amount of timezone offset.
== BUGS
You may *not* use the *-r* option, as the format for the utmp/wtmp files strongly depends on the input format. This tool was *not* written for normal use, but for debugging only.