misc-utils/logger.1.adoc

   1 //po4a: entry man manual
   2 ////
   3 Copyright (c) 1983, 1990, 1993
   4         The Regents of the University of California.  All rights reserved.
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  33
  34         @(#)logger.1    8.1 (Berkeley) 6/6/93
  35 ////
  36 = logger(1)
  37 :doctype: manpage
  38 :man manual: User Commands
  39 :man source: util-linux {release-version}
  40 :page-layout: base
  41 :command: logger
  42
  43 == NAME
  44
  45 logger - enter messages into the system log
  46
  47 == SYNOPSIS
  48
  49 *logger* [options] _message_
  50
  51 == DESCRIPTION
  52
  53 *logger* makes entries in the system log.
  54
  55 When the optional _message_ argument is present, it is written to the log. If it is not present, and the *-f* option is not given either, then standard input is logged.
  56
  57 == OPTIONS
  58
  59 *-d*, *--udp*::
  60 Use datagrams (UDP) only. By default the connection is tried to the syslog port defined in _/etc/services_, which is often 514.
  61 +
  62 See also *--server* and *--socket* to specify where to connect.
  63
  64 *-e*, *--skip-empty*::
  65 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>*).
  66
  67 *-f*, *--file* _file_::
  68 Log the contents of the specified _file_. This option cannot be combined with a command-line message.
  69
  70 *-i*::
  71 Log the PID of the *logger* process with each line.
  72
  73 *--id*[**=**__id__]::
  74 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.
  75 +
  76 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. *logger*(1) 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.
  77
  78 *--journald*[**=**__file__]::
  79 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:
  80
  81 ____
  82     logger --journald <<end
  83     MESSAGE_ID=67feb6ffbaf24c5cbec13c008dd72309
  84     MESSAGE=The dogs bark, but the caravan goes on.
  85     DOGS=bark
  86     CARAVAN=goes on
  87     end
  88
  89     logger --journald=entry.txt
  90 ____
  91 Notice that *--journald* will ignore values of other options, such as priority. If priority is needed it must be within input, and use PRIORITY field. The simple execution of *journalctl*(1) will display MESSAGE field. Use *journalctl --output json-pretty* to see rest of the fields.
  92 +
  93 To include newlines in MESSAGE, specify MESSAGE several times. This is handled as a special case, other fields will be stored as an array in the journal if they appear multiple times.
  94
  95 *--msgid* _msgid_::
  96 Sets the link:https://tools.ietf.org/html/rfc5424[RFC 5424] 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.
  97
  98 *-n*, *--server* _server_::
  99 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.
 100
 101 *--no-act*::
 102 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.
 103
 104 *--octet-count*::
 105 Use the link:https://tools.ietf.org/html/rfc6587[RFC 6587] 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.
 106
 107 *-P*, *--port* _port_::
 108 Use the specified _port_. When this option is not specified, the port defaults to *syslog* for udp and to *syslog-conn* for tcp connections.
 109
 110 *-p*, *--priority* _priority_::
 111 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*.
 112
 113 *--prio-prefix*::
 114 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>*.
 115 +
 116 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*.
 117 +
 118 This option doesn't affect a command-line message.
 119
 120 *--rfc3164*::
 121 Use the link:https://tools.ietf.org/html/rfc3164[RFC 3164] BSD syslog protocol to submit messages to a remote server.
 122
 123 *--rfc5424*[**=**__without__]::
 124 Use the link:https://tools.ietf.org/html/rfc5424[RFC 5424] 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*.
 125 +
 126 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.
 127 +
 128 The *notime* value (which implies *notq*) suppresses the complete sender timestamp that is in ISO-8601 format, including microseconds and timezone.
 129 +
 130 The *nohost* value suppresses *gethostname*(2) information from the message header.
 131 +
 132 The RFC 5424 protocol has been the default for *logger* since version 2.26.
 133
 134 *-s*, *--stderr*::
 135 Output the message to standard error as well as to the system log.
 136
 137 *--sd-id* _name_[**@**__digits__]::
 138 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.
 139 +
 140 *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.
 141
 142 *--sd-param* _name_=_value_::
 143 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.
 144 +
 145 ....
 146     logger --rfc5424 --sd-id zoo@123             \
 147                      --sd-param tiger="hungry"   \
 148                      --sd-param zebra="running"  \
 149                      --sd-id manager@123         \
 150                      --sd-param onMeeting="yes"  \
 151                      "this is message"
 152 ....
 153 produces:
 154 +
 155 *<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*
 156
 157 *-S*, *--size* _size_::
 158 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.
 159 +
 160 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).
 161 +
 162 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.
 163
 164 *--socket-errors*[**=**__mode__]::
 165 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 *logger*(1) before version 2.26 used *openlog*(3), and hence was unable to detected loss of messages sent to Unix sockets.
 166 +
 167 The default mode is *auto*. When errors are not enabled lost messages are not communicated and will result to successful exit status of *logger*(1) invocation.
 168
 169 *-T*, *--tcp*::
 170 Use stream (TCP) only. By default the connection is tried to the _syslog-conn_ port defined in _/etc/services_, which is often _601_.
 171 +
 172 See also *--server* and *--socket* to specify where to connect.
 173
 174 *-t*, *--tag* _tag_::
 175 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).
 176
 177 *-u*, *--socket* _socket_::
 178 Write to the specified _socket_ instead of to the system log socket.
 179
 180 *--*::
 181 End the argument list. This allows the _message_ to start with a hyphen (-).
 182
 183 include::man-common/help-version.adoc[]
 184
 185 == EXIT STATUS
 186
 187 The *logger* utility exits 0 on success, and >0 if an error occurs.
 188
 189 == FACILITIES AND LEVELS
 190
 191 Valid facility names are:
 192
 193 *auth* +
 194 *authpriv* for security information of a sensitive nature +
 195 *cron* +
 196
 197 *daemon* +
 198 *ftp* +
 199 *kern* cannot be generated from userspace process, automatically converted to *user* +
 200
 201 *lpr* +
 202 *mail* +
 203 *news* +
 204 *syslog* +
 205 *user* +
 206 *uucp* +
 207 *local0* +
 208     to +
 209 *local7* +
 210 *security* deprecated synonym for *auth*
 211
 212 Valid level names are:
 213
 214 *emerg* +
 215 *alert* +
 216 *crit* +
 217 *err* +
 218 *warning* +
 219 *notice* +
 220 *info* +
 221 *debug* +
 222 *panic* deprecated synonym for *emerg* +
 223 *error* deprecated synonym for *err* +
 224 *warn* deprecated synonym for *warning* +
 225
 226 For the priority order and intended purposes of these facilities and levels, see *syslog*(3).
 227
 228 == CONFORMING TO
 229
 230 The *logger* command is expected to be IEEE Std 1003.2 ("POSIX.2") compatible.
 231
 232 == EXAMPLES
 233
 234 *logger System rebooted* *logger -p local0.notice -t HOSTIDM -f /dev/idmc* *logger -n loghost.example.com System rebooted*
 235
 236 == AUTHORS
 237
 238 The *logger* command was originally written by University of California in 1983-1993 and later rewritten by mailto:kzak@redhat.com[Karel Zak], mailto:rgerhards@adiscon.com[Rainer Gerhards], and mailto:kerolasa@iki.fi[Sami Kerola].
 239
 240 == SEE ALSO
 241
 242 *journalctl*(1),
 243 *syslog*(3),
 244 *systemd.journal-fields*(7)
 245
 246 include::man-common/bugreports.adoc[]
 247
 248 include::man-common/footer.adoc[]
 249
 250 ifdef::translation[]
 251 include::man-common/translation.adoc[]
 252 endif::[]