---
name: "logcheck"
section: "8"
platform: "linux"
package: "logcheck"
version: "1.4.5+deb13u1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/logcheck"
---

# logcheck(8)

program to scan system logs for interesting lines

## 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-security 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 machines and filters most of the messages.  The ignore rules work in additive 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,  security events and attack alerts. The verbosity of system events is  controlled 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)](/sudo/8.md), 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)](/logtail/8.md)

## AUTHOR

logcheck is developed by Debian logcheck Team at:  https://salsa.debian.org/debian/logcheck.

This manual page was written by Jon Middleton.