System information

Detailed Description

The functions in this package provide access to information about the system.

Functions
	system.scriptid ()
	Retrieve the id of the currently running pipeline script. More...
	system.version ()
	Retrieve the version of the currently running pipeline module. More...
	system.expand (var pattern)
	Perform substitutions on a string. More...
	system.threadindex (var pattern)
	Return the current thread number. More...
	system.get_pipeline (var scriptid)
	Return configuration information for the specified pipeline. More...
	system.delete_pipeline (var scriptid)
	Delete the specified pipeline. More...
	system.millitime ()
	Return the number of milliseconds since the Epoch. More...
	system.time ()
	Return the number of seconds since the Epoch. More...
	system.difftime (var time0, var time1)
	Calculate time difference. More...
	system.udpsignal_send (var msg)
	Send a UDP message to this Transformer. More...
	system.udp_sendto (var addr, var port, var message)
	Send data to a UDP address. More...
	system.set_status_down (var peer_label)
	Set peer status down. More...
	system.set_status_up (var peer_label)
	Set peer status up. More...
	system.peer_label_byindex (var index)
	Return the peer label corresponding to a peer index. More...
	system.peer_index_bylabel (var label)
	Returns the peer index corresponding to a peer label. More...
	system.peer_status_bylabel (var label)
	Returns the peer status for a given peer label. More...
	system.num_peers ()
	Return the number of configured peers in the system ( if Discovery mode if off ) Return the highest peer index ( if Discovery mode if on ) More...
	system.strptime (var timestamp, var format)
	Parse a timestamp according the give timestamp format. More...
	system.peer_enabled_bylabel (var label)
	Returns whether a peer is enabled or not. More...
	system.hostname ()
	Returns the hostname. More...
	system.pipelines_for_symbol (var name)
	Returns the pipeline id's for a given symbol. More...
	system.get_log_level ()
	Get the current logging level for the pipeline log. More...

Function Documentation

system.delete_pipeline

(

var

scriptid

)

Delete the specified pipeline.

Parameters

scriptid

- The scriptid of the pipeline which will be deleted

Return values

0	- Success
nil	- Failure (pipeline does not exist)

This function will delete the in-memory configuration of the specified pipeline. No more events will be passed into the pipeline and its configuration cannot be retrieved after this call.

system.difftime	(	var	time0,
		var	time1
	)

Calculate time difference.

Parameters

time0	- First time
time1	- Second time

Returns

The number of seconds elapsed between time time1 and time time0

system.expand

(

var

pattern

)

Perform substitutions on a string.

Parameters

pattern

- The string to perform substituions on

Returns

An expanded string with all appropriate substitutions made

This function will expand the following tokens in the supplied argument:

• %h The hostname
• %a The application name (as set by the configuration option application-name)
• %n The application name (as set by the configuration option application-name)
• %r The application root (as set by the configuration option application-root)
• %u The home directory of the process owner.

system.get_log_level

(

)

Get the current logging level for the pipeline log.

Returns

- The logging level. See Logging routines for the possible values

system.get_pipeline

(

var

scriptid

)

Return configuration information for the specified pipeline.

Parameters

scriptid

- The scriptid of the pipeline whose configuration should be returned

This function will return an object of type Dynamic pipeline configuration that can be queried and set to adjust the configuration of the specified pipeline

system.hostname

(

)

Returns the hostname.

Returns

The hostname

system.millitime

(

)

Return the number of milliseconds since the Epoch.

Return values

number

of milliseconds since the Epoch

system.num_peers

(

)

Return the number of configured peers in the system ( if Discovery mode if off ) Return the highest peer index ( if Discovery mode if on )

Returns

The number of peers

system.peer_enabled_bylabel

(

var

label

)

Returns whether a peer is enabled or not.

Parameters

label

- Peer label to return the state for

Return values

0	- Peer is disabled
1	- Peer is enabled

system.peer_index_bylabel

(

var

label

)

Returns the peer index corresponding to a peer label.

Parameters

label

- Peer label to return the index for

Returns

The peer index

Return values

-1	- Peer label not known

system.peer_label_byindex

(

var

index

)

Return the peer label corresponding to a peer index.

Parameters

index

- Peer index to return the label for

Returns

The peer label

Return values

Peer<index>

- If peer index is not defined

system.peer_status_bylabel

(

var

label

)

Returns the peer status for a given peer label.

Parameters

label

- Peer label to return the status for

Return values

0	- Peer is down
1	- Peer is up

system.pipelines_for_symbol

(

var

name

)

Returns the pipeline id's for a given symbol.

Parameters

name	- Name of symbol

Returns

- A table containing the id's of the matching pipelines

Return values

nil	- No matching pipleines found

system.scriptid

(

)

Retrieve the id of the currently running pipeline script.

Returns

The script id

The id that is returned is that configured in add-pipeline configuration group

system.set_status_down

(

var

peer_label

)

Set peer status down.

Parameters

peer_label

- Label of peer to send status to - if not present then status sent to all peers

Return values

0	- Success
-1	- peer_label did not match any peers

system.set_status_up

(

var

peer_label

)

Set peer status up.

Parameters

peer_label

- Label of peer to send status to - if not present then status sent to all peers

Return values

0	- Success
-1	- peer_label did not match any peers

system.strptime	(	var	timestamp,
		var	format
	)

Parse a timestamp according the give timestamp format.

Parameters

timestamp	- Time stamp to parse
format	- The format to apply

Returns

A table containing information regarding the date

Return values

nil	- The timestamp could not be parsed

The table has the following fields: year (four digits), month (1–12), day (1–31), hour (0–23), min (0–59), sec (0–61), wday (weekday, Sunday is 1), yday (day of the year), and isdst (daylight saving flag, a boolean).

To obtain a value in unix timestamp format the returned table can be supplied to the standard os.time() function, and then operations such as difftime may be applied.

Should format not be supplied, then the format defaults to: "%Y-%m-%dT%H:%M:%SZ" as per timers

system.threadindex

(

var

pattern

)

Return the current thread number.

Returns

The currently executing thread index

This function will return the current thread number (from 0 to num-threads - 1). It is primarily of use for testing purposes

system.time

(

)

Return the number of seconds since the Epoch.

Return values

number

of seconds since the Epoch

system.udp_sendto	(	var	addr,
		var	port,
		var	message
	)

Send data to a UDP address.

Parameters

addr	- The host name or IP address for the UDP port
port	- The UDP port number
message	- The data to send

Return values

Number	of bytes sent
-1	- Error sending message

system.udpsignal_send

(

var

msg

)

Send a UDP message to this Transformer.

Parameters

msg	- The message to send in the form "COMMAND ARG1 ARG2 ..."

Return values

None

Note

The UDP command should be the first field of the message string.

system.version

(

)

Retrieve the version of the currently running pipeline module.

Returns

Pipeline module version

The version returned is in the form X.Y.Z where X is the major, Y the minor and Z the patch version.