The following macros are available in syslog-ng OSE.

CAUTION: These macros are available when syslog-ng OSE successfully parses the incoming message as a syslog message, or you use some other parsing method and map the parsed values to these macros.

If you are using the flags(no-parse) option, then syslog message parsing is completely disabled, and the entire incoming message is treated as the MESSAGE part of a syslog message.
In this case, syslog-ng OSE generates a new syslog header (timestamp, host, and so on) automatically. Note that even though flags(no-parse) disables message parsing, some flags can still be used, for example, the no-multi-line flag.

${AMPM}

Typically used together with the ${HOUR12} macro, ${AMPM} returns the period of the day: AM for hours before mid day and PM for hours after mid day. In reference to a 24-hour clock format, AM is between 00:00-12:00 and PM is between 12:00-24:00. 12AM is midnight. Available in syslog-ng OSE 3.4 and later.

${BSDTAG}

Facility/priority information in the format used by the FreeBSD syslogd: a priority number followed by a letter that indicates the facility. The priority number can range from 0 to 7. The facility letter can range from A to Y, where A corresponds to facility number zero (LOG_KERN), B corresponds to facility 1 (LOG_USER), and so on.

Custom macros

CSV parsers and pattern databases can also define macros from the content of the messages, for example, a pattern database rule can extract the username from a login message and create a macro that references the username. For details on using custom macros created with CSV parsers and pattern databases, see parser: Parse and segment structured messages and Using parser results in filters and templates, respectively.

${DATE}, ${C_DATE}, ${R_DATE}, ${S_DATE}

Date of the message using the BSD-syslog style timestamp format (month/day/hour/minute/second, each expressed in two digits). This is the original syslog time stamp without year information, for example: Jun 13 15:58:00.

${DAY}, ${C_DAY}, ${R_DAY}, ${S_DAY}

The day the message was sent.

${DESTIP}

When used, the output specifies the local IP address of the source from which the message originates.

For an example use case when using the macro is recommended, see Example use case: using the ${DESTIP}, the ${DESTPORT}, and the ${PROTO} macros

${DESTPORT}

When used, the output specifies the local port of the source from which the message originates.

For an example use case when using the macro is recommended, see Example use case: using the ${DESTIP}, the ${DESTPORT}, and the ${PROTO} macros.

${FACILITY}

The name of the facility (for example, kern) that sent the message.

${FACILITY_NUM}

The numerical code of the facility (for example, 0) that sent the message.

${FILE_NAME}

Name of the log file (including its path) from where syslog-ng OSE received the message (only available if syslog-ng OSE received the message from a file or a wildcard-file).
If you need only the path or the filename, use the dirname and basename template functions.

${FULLDATE}, ${C_FULLDATE}, ${R_FULLDATE}, ${S_FULLDATE}

A nonstandard format for the date of the message using the same format as ${DATE}, but including the year as well, for example: 2006 Jun 13 15:58:00.

${FULLHOST}

The name of the source host where the message originates from.

For details on using name resolution in syslog-ng OSE, see Using name resolution in syslog-ng.

${FULLHOST_FROM}

The FQDN of the host that sent the message to syslog-ng as resolved by syslog-ng OSE using DNS. If the message traverses several hosts, this is the last host in the chain.

The syslog-ng OSE application uses the following procedure to determine the value of the macro:

  1. The syslog-ng OSE application takes the IP address of the host sending the message.

  2. If the use-dns() option is enabled, syslog-ng OSE attempts to resolve the IP address to a hostname. If it succeeds, the returned hostname will be the value of the macro. This value will be the FQDN of the host if the use-fqdn() option is enabled, but only the hostname if use-fqdn() is disabled.

  3. If the use-dns() option is disabled, or the address resolution fails, the macro will return the IP address of the sender host.

For details on using name resolution in syslog-ng OSE, see Using name resolution in syslog-ng.

${HOUR}, ${C_HOUR}, ${R_HOUR}, ${S_HOUR}

The hour of day the message was sent.

${HOUR12}, ${C_HOUR12}, ${R_HOUR12}, ${S_HOUR12}

The hour of day the message was sent in 12-hour clock format. See also the ${AMPM} macro. 12AM is midnight. Available in syslog-ng OSE 3.4 and later.

${HOST}

The name of the source host where the message originates from.

For details on using name resolution in syslog-ng OSE, see Using name resolution in syslog-ng.

${HOST_FROM}

The FQDN of the host that sent the message to syslog-ng as resolved by syslog-ng OSE using DNS. If the message traverses several hosts, this is the last host in the chain.

The syslog-ng OSE application uses the following procedure to determine the value of the ${HOST_FROM} macro:

  1. The syslog-ng OSE application takes the IP address of the host sending the message.

  2. If the use-dns() option is enabled, syslog-ng OSE attempts to resolve the IP address to a hostname. If it succeeds, the returned hostname will be the value of the ${HOST_FROM} macro. This value will be the FQDN of the host if the use-fqdn() option is enabled, but only the hostname if use-fqdn() is disabled.

  3. If the use-dns() option is disabled, or the address resolution fails, the ${HOST_FROM} macro will return the IP address of the sender host.

For details on using name resolution in syslog-ng OSE, see Using name resolution in syslog-ng.

${ISODATE}, ${C_ISODATE}, ${R_ISODATE}, ${S_ISODATE}

Date of the message in the ISO 8601 compatible standard timestamp format (yyyy-mm-ddThh:mm:ss+-ZONE), for example: 2006-06-13T15:58:00.123+01:00. If possible, it is recommended to use ${ISODATE} for timestamping. Note that syslog-ng OSE can produce fractions of a second (for example, milliseconds) in the timestamp by using the frac-digits() global or per-destination option.

NOTE: As syslog-ng OSE is precise up to the microsecond, when the frac-digits() option is set to a value higher than 6, syslog-ng OSE will truncate the fraction seconds in the timestamps after 6 digits.

${ISOWEEK}, ${C_ISOWEEK}, ${R_ISOWEEK}, ${S_ISOWEEK}

The number of week according to the ISO 8601 standard. Note that the ${WEEK} macro that has been available in returns a non-standard week number that can differ from the value returned by the ${ISOWEEK} macro.

Available in 3.24 and later.

${LEVEL_NUM}

The priority (also called severity) of the message, represented as a numeric value, for example, 3. For the textual representation of this value, use the ${LEVEL} macro. See ${PRIORITY} or ${LEVEL} for details.

${LOGHOST}

The hostname of the computer running syslog-ng OSE.

${MESSAGE}

Text contents of the log message without the program name and pid. The program name and the pid together are available in the ${MSGHDR} and ${PID} macros.

If you are using the flags(no-parse) option, then syslog message parsing is completely disabled, and the entire incoming message is treated as the MESSAGE part of a syslog message. In this case, syslog-ng OSE generates a new syslog header (timestamp, host, and so on) automatically. Note that even though flags(no-parse) disables message parsing, some flags can still be used, for example, the no-multi-line flag.

The ${MSG} macro is an alias of the ${MESSAGE} macro: using ${MSG} in syslog-ng OSE is equivalent to ${MESSAGE}.

Note that before syslog-ng OSE version 3.0, the ${MESSAGE} macro included the program name and the pid. In syslog-ng OSE 3.0, the ${MESSAGE} macro became equivalent with the ${MSGONLY} macro.

${MIN}, ${C_MIN}, ${R_MIN}, ${S_MIN}

The minute the message was sent.

${MONTH}, ${C_MONTH}, ${R_MONTH}, ${S_MONTH}

The month the message was sent as a decimal value, prefixed with a zero if smaller than 10.

${MONTH_ABBREV}, ${C_MONTH_ABBREV}, ${R_MONTH_ABBREV}, ${S_MONTH_ABBREV}

The English abbreviation of the month name (3 letters).

${MONTH_NAME}, ${C_MONTH_NAME}, ${R_MONTH_NAME}, ${S_MONTH_NAME}

The English name of the month name.

${MONTH_WEEK}, ${C_MONTH_WEEK}, ${R_MONTH_WEEK}, ${S_MONTH_WEEK}

The number of the week in the given month (0-5). The week with numerical value 1 is the first week containing a Monday. The days of month before the first Monday are considered week 0. For example, if a 31-day month begins on a Sunday, then the 1st of the month is week 0, and the end of the month (the 30th and 31st) is week 5.

${MSEC}, ${C_MSEC}, ${R_MSEC}, ${S_MSEC}

The millisecond the message was sent.

Available in syslog-ng OSE version 3.4 and later.

${MQTT_TOPIC}

This macro is available in syslog-ng OSE 4.7 and later versions. The mqtt() source sets the ${MQTT_TOPIC} name-value pair automatically for the messages it receives. This macro can be used when the name of the topic contains MQTT wildcards characters ($, +, #). For more information, see mqtt: Receiving messages from an MQTT broker.

${MSG}

The ${MSG} macro is an alias of the ${MESSAGE} macro, using ${MSG} in syslog-ng OSE is equivalent to ${MESSAGE}. For details on this macro, see ${MESSAGE}.

${MSGHDR}

The name and the PID of the program that sent the log message in PROGRAM[PID]: format. Includes a trailing whitespace. Note that the macro returns an empty value if both the PROGRAM and PID fields of the message are empty.

${MSGID}

A string specifying the type of the message in IETF-syslog (RFC-5424 formatted) messages. For example, a firewall might use the ${MSGID} "TCPIN" for incoming TCP traffic and the ${MSGID} "TCPOUT" for outgoing TCP traffic. By default, syslog-ng OSE does not specify this value, but uses a dash (-) character instead. If an incoming message includes the ${MSGID} value, it is retained and relayed without modification.

${MSGONLY}

Message contents without the program name or pid. Starting with syslog-ng OSE 3.0, the following macros are equivalent: ${MSGONLY}, ${MSG}, ${MESSAGE}. For consistency, use the ${MESSAGE} macro. For details, see ${MESSAGE}.

${PID}

The PID of the program sending the message.

${PRI}

The priority and facility encoded as a 2 or 3 digit decimal number as it is present in syslog messages.

${PRIORITY} or ${LEVEL}

The priority (also called severity) of the message, for example, error. For the textual representation of this value, use the ${LEVEL} macro.

${PROGRAM}

The name of the program sending the message. Note that the content of the ${PROGRAM} variable may not be completely trusted as it is provided by the client program that constructed the message.

${PROTO}

Description: When used, the output specifies the protocol used on the source from which the message originates.

For an example use case when using the macro is recommended, see Example use case: using the ${DESTIP}, the ${DESTPORT}, and the ${PROTO} macros.

${RAWMSG}

The original message as received from the client. Note that this macro is available only in 3.16 and later, and only if syslog-ng OSE received the message using the default-network-drivers() source, or the source receiving the message has the store-raw-message flag set.

${RCPTID}

When the use-rcptid global option is set to yes, syslog-ng OSE automatically assigns a unique reception ID to every received message. You can access this ID and use it in templates via the ${RCPTID} macro. The reception ID is a monotonously increasing 48-bit integer number, that can never be zero (if the counter overflows, it restarts with 1).

${RUNID}

An ID that changes its value every time syslog-ng OSE is restarted, but not when reloaded.

${SDATA}, ${.SDATA.SDID.SDNAME}

The syslog-ng OSE application automatically parses the STRUCTURED-DATA part of IETF-syslog messages, which can be referenced in macros. The ${SDATA} macro references the entire STRUCTURED-DATA part of the message, while structured data elements can be referenced using the ${.SDATA.SDID.SDNAME} macro.

NOTE: When using STRUCTURED-DATA macros, consider the following:

  • When referencing an element of the structured data, the macro must begin with the dot (.) character. For example, ${.SDATA.timeQuality.isSynced}.

  • The SDID and SDNAME parts of the macro names are case sensitive: ${.SDATA.timeQuality.isSynced} is not the same as ${.SDATA.TIMEQUALITY.ISSYNCED}.

Example: Using ${SDATA} macros

For example, if a log message contains the following structured data: [exampleSDID@0 iut="3" eventSource="Application" eventID="1011"][examplePriority@0 class="high"] you can use macros like: ${.SDATA.exampleSDID@0.eventSource} — this would return the Application string in this case.

${SEC}, ${C_SEC}, ${R_SEC}, ${S_SEC}

The second the message was sent.

${SEQNUM}

The ${SEQNUM} macro contains a sequence number for the log message. The value of the macro depends on the scenario, and can be one of the following:

  • If syslog-ng OSE receives a message via the IETF-syslog protocol that includes a sequence ID, this ID is automatically available in the ${SEQNUM} macro.

  • If the message is a Cisco IOS log message using the extended timestamp format, then syslog-ng OSE stores the sequence number from the message in this macro. If you forward this message the IETF-syslog protocol, syslog-ng OSE includes the sequence number received from the Cisco device in the .SDATA.meta.sequenceId part of the message.

    NOTE: To enable sequence numbering of log messages on Cisco devices, use the following command on the device (available in IOS 10.0 and later): service sequence-numbers. For details, see the manual of your Cisco device.

  • For locally generated messages (that is, for messages that are received from a local source, and not from the network), syslog-ng OSE calculates a sequence number when sending the message to a destination (it is not calculated for relayed messages).

    • The sequence number is not global, but per-destination. Essentially, it counts the number of messages sent to the destination.

    • This sequence number increases by one for every message sent to the destination. It not lost when syslog-ng OSE is reloaded, but it is reset when syslog-ng OSE is restarted.

    • This sequence number is added to every message that uses the IETF-syslog protocol (${.SDATA.meta.sequenceId}), and can be added to BSD-syslog messages using the ${SEQNUM} macro.

NOTE: If you need a sequence number for every log message that syslog-ng OSE receives, use the ${RCPTID} macro.

${SOURCE}

The identifier of the source statement in the syslog-ng OSE configuration file that received the message. For example, if syslog-ng OSE received the log message from the source s_local { internal(); }; source statement, the value of the ${SOURCE} macro is s_local. This macro is mainly useful for debugging and troubleshooting purposes.

${SOURCEIP}

IP address of the host that sent the message to syslog-ng. (That is, the IP address of the host in the ${FULLHOST_FROM} macro.) Please note that when a message traverses several relays, this macro contains the IP of the last relay.

${STAMP}, ${R_STAMP}, ${S_STAMP}

A timestamp formatted according to the Global options global or per-destination option.

${SYSUPTIME}

The time elapsed since the syslog-ng OSE instance was started (that is, the uptime of the syslog-ng OSE process). The value of this macro is an integer containing the time in 1/100th of the second.

Available in syslog-ng OSE version 3.4 and later.

${TAG}

The priority and facility encoded as a 2 digit hexadecimal number.

${TAGS}

A comma-separated list of the tags assigned to the message.

NOTE: Note that the tags are not part of the log message and are not automatically transferred from a client to the server. For example, if a client uses a pattern database to tag the messages, the tags are not transferred to the server. A way of transferring the tags is to explicitly add them to the log messages using a template and the ${TAGS} macro, or to add them to the structured metadata part of messages when using the IETF-syslog message format.

When sent as structured metadata, it is possible to reference to the list of tags on the central server, and for example, to add them to a database column.

${TZ}, ${C_TZ}, ${R_TZ}, ${S_TZ}

An alias of the ${TZOFFSET} macro.

${TRANSPORT}

This macro is available in syslog-ng OSE 4.5 and later versions. The syslog-ng OSE application automatically populates this name-value pair with the transport-mechanism used to retrieve the message. The value depends on the source driver that received the message. The implemented values are the following:

  • BSD syslog drivers tcp(), udp() & network()
    • rfc3164+tls
    • rfc3164+tcp
    • rfc3164+udp
    • rfc3164+proxied-tcp
    • rfc3164+proxied-tls
    • rfc3164+proxied-tls-passthrough
    • rfc3164+ <custom logproto like altp>
  • UNIX domain drivers unix-dgram(), unix-stream()
    • unix-stream
    • unix-dgram
  • rfc5424 style syslog syslog():
    • rfc5426+udp
    • rfc6587+tcp
    • rfc6587+proxied-tcp
    • rfc5425+tls
    • rfc5424+proxied-tls
    • rfc5424+proxied-tls-passthrough
    • rfc5424+<custom logproto like altp>: syslog over a logproto plugin
  • Other drivers:
    • otlp: otel() driver
    • mqtt: mqtt() driver
    • hypr-api: hypr-audit-trail() driver
  • Locally created logs (available in 4.7 and later versions):
    • local+unix-stream
    • local+unix-dgram
    • local+file
    • local+pipe
    • local+program
    • local+devkmsg
    • local+journal
    • local+afstreams
    • local+openbsd

${TZOFFSET}, ${C_TZOFFSET}, ${R_TZOFFSET}, ${S_TZOFFSET}

The time-zone as hour offset from GMT, for example: -07:00. In syslog-ng OSE 1.6.x this used to be -0700 but as ${ISODATE} requires the colon it was added to ${TZOFFSET} as well.

${UNIXTIME}, ${C_UNIXTIME}, ${R_UNIXTIME}, ${S_UNIXTIME}

Standard UNIX timestamp, represented as the number of seconds since 1970-01-01T00:00:00.

${.tls.x509}

When using a transport that uses TLS, these macros contain information about the peer's certificate. That way, you can use information from the client certificate in filenames, database values, or as other metadata. If you clients have their own certificates, then these values are unique per client, but unchangeable by the client. The following macros are available in syslog-ng OSE version 3.9 and later.

  • .tls.x509_cn: The Common Name of the certificate.

  • .tls.x509_o: The value of the Organization field.

  • .tls.x509_ou: The value of the Organization Unit field.

${UNIQID}

A globally unique ID generated from the HOSTID and the RCPTID in the format of HOSTID@RCPTID. For details, see use-uniqid() and ${RCPTID}.

Available in syslog-ng OSE version 3.7 and later.

${USEC}, ${C_USEC}, ${R_USEC}, ${S_USEC}

The microsecond the message was sent.

Available in syslog-ng OSE version 3.4 and later.

${YEAR}, ${C_YEAR}, ${R_YEAR}, ${S_YEAR}

The year the message was sent.

${WEEK}, ${C_WEEK}, ${R_WEEK}, ${S_WEEK}

The week number of the year, prefixed with a zero for the first nine weeks of the year. (The first Monday in the year marks the first week.)

See also ${ISOWEEK}, ${C_ISOWEEK}, ${R_ISOWEEK}, ${S_ISOWEEK}.

${WEEK_DAY_ABBREV}, ${C_WEEK_DAY_ABBREV}, ${R_WEEK_DAY_ABBREV}, ${S_WEEK_DAY_ABBREV}

The 3-letter English abbreviation of the name of the day the message was sent, for example, Thu.

${WEEK_DAY}, ${C_WEEK_DAY}, ${R_WEEK_DAY}, ${S_WEEK_DAY}

The day of the week as a numerical value (1-7).

${WEEKDAY}, ${C_WEEKDAY}, ${R_WEEKDAY}, ${S_WEEKDAY}

These macros are deprecated, use ${WEEK_DAY_ABBREV}, ${R_WEEK_DAY_ABBREV}, ${S_WEEK_DAY_ABBREV} instead. The 3-letter name of the day of week the message was sent, for example, Thu.

${WEEK_DAY_NAME}, ${C_WEEK_DAY_NAME}, ${R_WEEK_DAY_NAME}, ${S_WEEK_DAY_NAME}

The English name of the day.

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