Logcheck(8) System Manager's Manual Logcheck(8)
NAME
logcheck — program to scan system logs for interesting lines
SYNOPSIS
logcheck [OPTIONS]
DESCRIPTION
The logcheck program helps spot problems and security violations in your
logfiles automatically and will send the results to you periodically in
an e-mail. By default logcheck runs as an hourly cronjob just off the
hour and after every reboot.
logcheck supports three level of filtering: "paranoid" is for high-secu-
rity machines running as few services as possible. Don't use it if you
can't handle its verbose messages. "server" is the default and contains
rules for many different daemons. "workstation" is for sheltered ma-
chines and filters most of the messages. The ignore rules work in addi-
tive manner. "paranoid" rules are also included at level "server".
"workstation" level includes both "paranoid" and "server" rules.
The messages reported are sorted into three layers, system events, secu-
rity events and attack alerts. The verbosity of system events is con-
trolled by which level you choose, paranoid, server or workstation.
However, security events and attack alerts are not affected by this.
EXAMPLES
logcheck can be invoked directly thanks to su(8) or sudo(8), which
change the user ID. The following example checks the logfiles without
updating the offset and outputs everything to STDOUT.
sudo -u logcheck logcheck -o -t
OPTIONS
A summary of options is included below.
-c CFG Overrule default configuration file.
-d Debug mode.
-h Show usage information.
-H Use this hostname string in the subject of logcheck mail.
-l LOG Run logfile through logcheck.
-L CFG Overrule default logfiles list.
-D DIR Overrule default logfiles lists directory.
-m MAIL Mail report to recipient.
-o STDOUT mode, not sending mail.
-p Set the report level to "paranoid".
-r DIR Overrule default rules directory.
-R Adds "Reboot:" to the email subject line.
-s Set the report level to "server".
-S DIR Overrule default state directory.
-t Testing mode does not update offset.
-T Do not remove the TMPDIR.
-u Enable syslog-summary.
-v Print current version.
-w Set the report level to "workstation".
FILES
/etc/logcheck/logcheck.conf is the main configuration file.
/etc/logcheck/logcheck.logfiles is the list of files to monitor.
/etc/logcheck/logcheck.logfiles.d is the directory of lists of files to
monitor.
/usr/share/doc/logcheck-database/README.logcheck-database.gz for hints
on how to write, test and maintain rules.
EXIT STATUS
0 upon success; 1 upon failure
SEE ALSO
logtail(8)
AUTHOR
logcheck is developed by Debian logcheck Team at: https://salsa.de-
bian.org/debian/logcheck.
This manual page was written by Jon Middleton.
Logcheck(8)
Generated by dwww version 1.16 on Tue Dec 16 06:42:46 CET 2025.