Nagios plugin check_logfiles

 check_logfiles: Plugin for Nagios which scans log files for specific patterns.
 Features:
  - Detection of rotations - usually nightly logfiles are rotated and
    compressed. Each operating system or company has it’s own naming
    scheme. If this rotation is done between two runs of check_logfiles
    also the rotated archive has to be scanned to avoid gaps. The most
    common rotation schemes are predefined but you can describe any
    strategy (shortly: where and under which name is a logfile
    archived).
  - More than one pattern can be defined which again can be classified
    as warning patterns and critical patterns.
  - Triggered actions - Usually nagios plugins return just an exit code
    and a line of text, describing the result of the check. Sometimes,
    however, you want to run some code during the scan every time you
    got a hit. Check_logfiles lets you call scripts either after every
    hit or at the beginning or the end of it’s runtime.
  - Exceptions - If a pattern matches, the matched line could be a very
    special case which should not be counted as an error. You can
    define exception patterns which are more specific versions of your
    critical/warning patterns. Such a match would then cancel an alert.
  - Thresholds - You can define the number of matching lines which are
    necessary to activate an alert.
  - Protocol - The matching lines can be written to a protocol file the
    name of which will be included in the plugin’s output.
  - Macros - Pattern definitions and logfile names may contain macros,
    which are resolved at runtime.
  - Performance data - The number of lines scanned and the number of
    warnings/criticals is output.
  - Windows - The plugin works with Unix as well as with Windows
    (e.g. with ActiveState Perl).