UTMPDUMP(1)                                                        User Commands                                                       UTMPDUMP(1)

NAME

       utmpdump - dump UTMP and WTMP files in raw format

SYNOPSIS

       utmpdump [options] [filename]

DESCRIPTION

       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 file-
       name is passed.

OPTIONS

       -f, --follow
              Output appended data as the file grows.

       -o, --output file
              Write command output to file instead of standard output.

       -r, --reverse
              Undump, write back edited login information into the utmp or wtmp files.

       -V, --version
              Display version information and exit.

       -h, --help
              Display help text and exit.

NOTES

       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
       The only 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.

AUTHOR

       Michael Krapp

SEE ALSO

       last(1), w(1), who(1), utmp(5)

AVAILABILITY

       The utmpdump command is part of the util-linux package and is available from Linux Kernel  Archive  <https://www.kernel.org/pub/linux/utils
       /util-linux/>.

util-linux                                                           July 2014                                                         UTMPDUMP(1)