modern syslog - streaming, async, native, uses nan

This is the only syslog library that:

- Uses native bindings to the libc syslog API.
- Is async, because the libc APIs can block on localhost IPC under load, but
that shouldn't block your app.
- Can be used as a stream.
- Has formatted log functions.
- Uses nan, so supports node and io.js, and will continue to do so.
- Is API compatible with [node-syslog][], from which I gathered inspiration
and owe thanks.

Default mask depends on system.

Installation

npm install --save modern-syslog

API

For detailed descriptions of the core functions, see man 3
syslog.

Note that syslog functions cannot fail, and neither throw errors, nor callback
with errors. This is consistent with the core functions, which do not have error
return values.

$3

- priority {String|Number} OR of a level, and optionally, a facility.
- msg {String|Buffer} Message to log.
- callback {Function} Called after message is logged (no arguments).

priority can be a String, in which case it will be looked up in
syslog.level. It can also be a Number, in which case it is expected to be
a numeric value, such as syslog.level.LOG_INFO, optionally ORed with a
a numeric facility, such as syslog.facility.LOG_LOCAL2.

See below for formatted version of log().

$3

- fmt {String} Arguments are formatted as msg, and passed to log().

Convenience functions, log level is pre-defined, facility uses default, either
system default or that provided to open(), and message is formatted with
util.format().

$3

- level {String|Number} Level to log at.
- facility {String|Number} Facility to log with, optional.

Returns a writeable stream that logs all messages at the specified level and
facility.

$3

- ident {String} Prepended to every message, usually program name.
- option {Number} OR of flags from syslog.options.
- facility {String|Number} Default facility to be used by log().

Set up defaults for log.

Calling open() is optional, all arguments are provided with defaults, though
the defaults depend on the system (see man page).

$3

Close the socket to the syslog system.

Calling close() is optional, the socket is closed automatically by the
system on exit.

$3

- level {String|Number} Level to log up to.

Log all levels upto and including level.

$3

- mask {Number} OR of levels that should be logged.

Not convenient to use but part of the low-level syslog API. See syslog man page
for details, and consider using upto() for most common use-cases.

$3

Returns current log mask, see setmask().

$3

Avoid this, its for backwards compatibility with [node-syslog][].

$3

Avoid this, its for backwards compatibility with [node-syslog][].

Properties

Syslog properties are defined as a bi-directional map from String to Number, and
from Number to String, so:

- syslog.level.LOG_DEBUG: 7, the numeric value of LOG_DEBUG
- syslog.level[7]: 'LOG_DEBUG', string value of level 7

$3

Levels are listed from highest priority, to lowest:

- LOG_EMERG: System is unusable.
- LOG_ALERT: Action must be taken immediately.
- LOG_CRIT: Critical condition.
- LOG_ERR: Error condition.
- LOG_WARNING: Warning condition.
- LOG_NOTICE: Normal, but significant, condition.
- LOG_INFO: Informational message.
- LOG_DEBUG: Debug-level message.

$3

Object of properties:

- LOG_CONS: Log to console if there is error logging to syslog.
- LOG_PERROR: Log to stderr as well as syslog. (no-op on Solaris)
- LOG_PID: Log process' PID with each message.

These are unlikely to be useful, but are provided for completeness:

- LOG_NDELAY: Open the connection immediately (normally, the connection is
opened when the first message is logged).
- LOG_ODELAY: The converse of LOG_NDELAY; opening of the connection is
delayed until the first message is logged (this is the default and need not be
specified).
- LOG_NOWAIT: Archaic option that doesn't do anything on contemporary systems,
but is provided for backwards compatibility.

$3

- LOG_AUTH
- LOG_AUTHPRIV (not defined on all systems)
- LOG_CRON
- LOG_DAEMON
- LOG_FTP (not defined on all systems)
- LOG_KERN
- LOG_LOCAL0
- LOG_LOCAL1
- LOG_LOCAL2
- LOG_LOCAL3
- LOG_LOCAL4
- LOG_LOCAL5
- LOG_LOCAL6
- LOG_LOCAL7
- LOG_LPR
- LOG_MAIL
- LOG_NEWS
- LOG_SYSLOG
- LOG_USER
- LOG_UUCP

[node-syslog]: https://www.npmjs.com/package/node-syslog

modern syslog - streaming, async, native, uses nan

This is the only syslog library that:

Default mask depends on system.

Installation

npm install --save modern-syslog

API

For detailed descriptions of the core functions, see man 3
syslog.

Note that syslog functions cannot fail, and neither throw errors, nor callback
with errors. This is consistent with the core functions, which do not have error
return values.

$3

- priority {String|Number} OR of a level, and optionally, a facility.
- msg {String|Buffer} Message to log.
- callback {Function} Called after message is logged (no arguments).

See below for formatted version of log().

$3

- fmt {String} Arguments are formatted as msg, and passed to log().

Convenience functions, log level is pre-defined, facility uses default, either
system default or that provided to open(), and message is formatted with
util.format().

$3

- level {String|Number} Level to log at.
- facility {String|Number} Facility to log with, optional.

Returns a writeable stream that logs all messages at the specified level and
facility.

$3

- ident {String} Prepended to every message, usually program name.
- option {Number} OR of flags from syslog.options.
- facility {String|Number} Default facility to be used by log().

Set up defaults for log.

Calling open() is optional, all arguments are provided with defaults, though
the defaults depend on the system (see man page).

$3

Close the socket to the syslog system.

Calling close() is optional, the socket is closed automatically by the
system on exit.

$3

- level {String|Number} Level to log up to.

Log all levels upto and including level.

$3

- mask {Number} OR of levels that should be logged.

Not convenient to use but part of the low-level syslog API. See syslog man page
for details, and consider using upto() for most common use-cases.

$3

Returns current log mask, see setmask().

$3

Avoid this, its for backwards compatibility with [node-syslog][].

$3

Avoid this, its for backwards compatibility with [node-syslog][].

Properties

Syslog properties are defined as a bi-directional map from String to Number, and
from Number to String, so:

- syslog.level.LOG_DEBUG: 7, the numeric value of LOG_DEBUG
- syslog.level[7]: 'LOG_DEBUG', string value of level 7

$3

Levels are listed from highest priority, to lowest:

$3

Object of properties:

- LOG_CONS: Log to console if there is error logging to syslog.
- LOG_PERROR: Log to stderr as well as syslog. (no-op on Solaris)
- LOG_PID: Log process' PID with each message.

These are unlikely to be useful, but are provided for completeness:

$3

[node-syslog]: https://www.npmjs.com/package/node-syslog