NAME
logger - enter messages into the system logSYNOPSIS
logger [options] messageDESCRIPTION
logger makes entries in the system log.OPTIONS
-d, --udpUse datagrams (UDP) only. By default the
connection is tried to the syslog port defined in /etc/services, which
is often 514.
See also --server and --socket to specify where to connect.
Ignore empty lines when processing files. An
empty line is defined to be a line without any characters. Thus a line
consisting only of whitespace is NOT considered empty. Note that when the
--prio-prefix option is specified, the priority is not part of the
line. Thus an empty line in this mode is a line that does not have any
characters after the priority prefix (e.g., <13>).
Log the contents of the specified file.
This option cannot be combined with a command-line message.
Log the PID of the logger process with
each line.
Log the PID of the logger process with
each line. When the optional argument id is specified, then it is used
instead of the logger command’s PID. The use of --id=$$
(PPID) is recommended in scripts that send several messages.
Note that the system logging infrastructure (for example systemd when
listening on /dev/log) may follow local socket credentials to overwrite
the PID specified in the message. is able to set those socket
credentials to the given id, but only if you have root permissions and
a process with the specified PID exists, otherwise the socket credentials are
not modified and the problem is silently ignored.
Write a systemd journal entry. The
entry is read from the given file, when specified, otherwise from
standard input. Each line must begin with a field that is accepted by
journald; see systemd.journal-fields(7) for details. The use of
a MESSAGE_ID field is generally a good idea, as it makes finding entries easy.
Examples:
logger --journald <<end MESSAGE_ID=67feb6ffbaf24c5cbec13c008dd72309 MESSAGE=The dogs bark, but the caravan goes on. DOGS=bark CARAVAN=goes on end
logger --journald=entry.txt
Sets the RFC 5424
<https://tools.ietf.org/html/rfc5424> MSGID field. Note that the space
character is not permitted inside of msgid. This option is only used if
--rfc5424 is specified as well; otherwise, it is silently
ignored.
Write to the specified remote syslog
server instead of to the system log socket. Unless --udp or
--tcp is specified, logger will first try to use UDP, but if
this fails a TCP connection is attempted.
Causes everything to be done except for
writing the log message to the system log, and removing the connection to the
journal. This option can be used together with --stderr for testing
purposes.
Use the RFC 6587
<https://tools.ietf.org/html/rfc6587> octet counting framing method for
sending messages. When this option is not used, the default is no framing on
UDP, and RFC6587 non-transparent framing (also known as octet stuffing) on
TCP.
Use the specified port. When this
option is not specified, the port defaults to syslog for udp and to
syslog-conn for tcp connections.
Enter the message into the log with the
specified priority. The priority may be specified numerically or as a
facility.level pair. For example, -p local3.info logs the
message as informational in the local3 facility. The default is
user.notice.
Look for a syslog prefix on every line read
from standard input. This prefix is a decimal number within angle brackets
that encodes both the facility and the level. The number is constructed by
multiplying the facility by 8 and then adding the level. For example,
local0.info, meaning facility=16 and level=6, becomes
<134>.
If the prefix contains no facility, the facility defaults to what is specified
by the -p option. Similarly, if no prefix is provided, the line is
logged using the priority given with -p.
This option doesn’t affect a command-line message.
Use the RFC 3164
<https://tools.ietf.org/html/rfc3164> BSD syslog protocol to submit
messages to a remote server.
Use the RFC 5424
<https://tools.ietf.org/html/rfc5424> syslog protocol to submit messages
to a remote server. The optional without argument can be a
comma-separated list of the following values: notq, notime,
nohost.
The notq value suppresses the time-quality structured data from the
submitted message. The time-quality information shows whether the local clock
was synchronized plus the maximum number of microseconds the timestamp might
be off. The time quality is also automatically suppressed when --sd-id
timeQuality is specified.
The notime value (which implies notq) suppresses the complete
sender timestamp that is in ISO-8601 format, including microseconds and
timezone.
The nohost value suppresses gethostname(2) information from the
message header.
The RFC 5424 protocol has been the default for logger since version
2.26.
Output the message to standard error as well
as to the system log.
Specifies a structured data element ID for an
RFC 5424 message header. The option has to be used before --sd-param to
introduce a new element. The number of structured data elements is unlimited.
The ID ( name plus possibly @digits) is case-sensitive
and uniquely identifies the type and purpose of the element. The same ID must
not exist more than once in a message. The @digits part is
required for user-defined non-standardized IDs.
logger currently generates the timeQuality standardized element
only. RFC 5424 also describes the elements origin (with parameters
ip, enterpriseId, software and swVersion) and
meta (with parameters sequenceId, sysUpTime and
language). These element IDs may be specified without the
@digits suffix.
Specifies a structured data element parameter,
a name and value pair. The option has to be used after --sd-id and may
be specified more than once for the same element. Note that the quotation
marks around value are required and must be escaped on the command
line.
produces:
<13>1 2015-10-01T14:07:59.168662+02:00 ws kzak - - [timeQuality
tzKnown="1" isSynced="1"
syncAccuracy="218616"][zoo@123 tiger="hungry"
zebra="running"][manager@123 onMeeting="yes"] this is
message
logger --rfc5424 --sd-id zoo@123 \ --sd-param tiger="hungry" \ --sd-param zebra="running" \ --sd-id manager@123 \ --sd-param onMeeting="yes" \ "this is message"
Sets the maximum permitted message size to
size. The default is 1KiB characters, which is the limit traditionally
used and specified in RFC 3164. With RFC 5424, this limit has become flexible.
A good assumption is that RFC 5424 receivers can at least process 4KiB
messages.
Most receivers accept messages larger than 1KiB over any type of syslog
protocol. As such, the --size option affects logger in all cases
(not only when --rfc5424 was used).
Note: the message-size limit limits the overall message size, including the
syslog header. Header sizes vary depending on the selected options and the
hostname length. As a rule of thumb, headers are usually not longer than 50 to
80 characters. When selecting a maximum message size, it is important to
ensure that the receiver supports the max size as well, otherwise messages may
become truncated. Again, as a rule of thumb two to four KiB message size
should generally be OK, whereas anything larger should be verified to
work.
Print errors about Unix socket connections.
The mode can be a value of off, on, or auto. When
the mode is auto, then logger will detect if the init process is
systemd(1), and if so assumption is made /dev/log can be used
early at boot. Other init systems lack of /dev/log will not cause
errors that is identical with messaging using openlog(3) system call.
The before version 2.26 used openlog(3), and hence was
unable to detected loss of messages sent to Unix sockets.
The default mode is auto. When errors are not enabled lost messages are
not communicated and will result to successful exit status of
invocation.
Use stream (TCP) only. By default the
connection is tried to the syslog-conn port defined in
/etc/services, which is often 601.
See also --server and --socket to specify where to connect.
Mark every line to be logged with the
specified tag. The default tag is the name of the user logged in on the
terminal (or a user name based on effective user ID).
Write to the specified socket instead
of to the system log socket.
End the argument list. This allows the
message to start with a hyphen (-).
Display help text and exit.
Print version and exit.
EXIT STATUS
The logger utility exits 0 on success, and >0 if an error occurs.FACILITIES AND LEVELS
Valid facility names are:CONFORMING TO
The logger command is expected to be IEEE Std 1003.2 ("POSIX.2") compatible.EXAMPLES
logger System rebooted logger -p local0.notice -t HOSTIDM -f /dev/idmc logger -n loghost.example.com System rebootedAUTHORS
The logger command was originally written by University of California in 1983-1993 and later rewritten by Karel <[email protected]>Zak Rainer <[email protected]>Gerhards and Sami <[email protected]>KerolaSEE ALSO
journalctl(1), syslog(3), systemd.journal-fields(7)REPORTING BUGS
For bug reports, use the issue tracker at <https://github.com/util-linux/util-linux/issues>.AVAILABILITY
The logger command is part of the util-linux package which can be downloaded from Linux Kernel Archive <https://www.kernel.org/pub/linux/utils/util-linux/>.2022-05-11 | util-linux 2.38.1 |