icinga2/doc/16-library-reference.md

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Library Reference

Global functions

Function Description
regex(pattern, text) Returns true if the regex pattern matches the text, false otherwise.
match(pattern, text) Returns true if the wildcard pattern matches the text, false otherwise.
len(value) Returns the length of the value, i.e. the number of elements for an array or dictionary, or the length of the string in bytes.
union(array, array, ...) Returns an array containing all unique elements from the specified arrays.
intersection(array, array, ...) Returns an array containing all unique elements which are common to all specified arrays.
keys(dict) Returns an array containing the dictionary's keys.
string(value) Converts the value to a string.
number(value) Converts the value to a number.
bool(value) Converts the value to a bool.
random() Returns a random value between 0 and RAND_MAX (as defined in stdlib.h).
log(value) Writes a message to the log. Non-string values are converted to a JSON string.
log(severity, facility, value) Writes a message to the log. severity can be one of LogDebug, LogNotice, LogInformation, LogWarning, and LogCritical. Non-string values are converted to a JSON string.
typeof(value) Returns the type object for a value.
exit(integer) Terminates the application.

Math object

The global Math object can be used to access a number of mathematical constants and functions.

Math.E

Euler's constant.

Math.LN2

Natural logarithm of 2.

Math.LN10

Natural logarithm of 10.

Math.LOG2E

Base 2 logarithm of E.

Math.PI

The mathematical constant Pi.

Math.SQRT1_2

Square root of 1/2.

Math.SQRT2

Square root of 2.

Math.abs

Signature:

function abs(x);

Returns the absolute value of x.

Math.acos

Signature:

function acos(x);

Returns the arccosine of x.

Math.asin

Signature:

function asin(x);

Returns the arcsine of x.

Math.atan

Signature:

function atan(x);

Returns the arctangent of x.

Math.atan2

Signature:

function atan2(y, x);

Returns the arctangent of the quotient of y and x.

Math.ceil

Signature:

function ceil(x);

Returns the smallest integer value not less than x.

Math.cos

Signature:

function cos(x);

Returns the cosine of x.

Math.exp

Signature:

function exp(x);

Returns E raised to the xth power.

Math.floor

Signature:

function floor(x);

Returns the largest integer value not greater than x.

Math.isinf

Signature:

function isinf(x);

Returns whether x is infinite.

Math.isnan

Signature:

function isnan(x);

Returns whether x is NaN (not-a-number).

Math.log

Signature:

function log(x);

Returns the natural logarithm of x.

Math.max

Signature:

function max(...);

Returns the largest argument. A variable number of arguments can be specified. If no arguments are given -Infinity is returned.

Math.min

Signature:

function min(...);

Returns the smallest argument. A variable number of arguments can be specified. If no arguments are given +Infinity is returned.

Math.pow

Signature:

function pow(x, y);

Returns x raised to the yth power.

Math.random

Signature:

function random();

Returns a pseudo-random number between 0 and 1.

Math.round

Signature:

function round(x);

Returns x rounded to the nearest integer value.

Math.sign

Signature:

function sign(x);

Returns -1 if x is negative, 1 if x is positive and 0 if x is 0.

Math.sin

Signature:

function sin(x);

Returns the sine of x.

Math.sqrt

Signature:

function sqrt(x);

Returns the square root of x.

Math.tan

Signature:

function tan(x);

Returns the tangent of x.

Number type

Number#to_string

Signature:

function to_string();

The to_string method returns a string representation of the number.

Example:

var example = 7
example.to_string() /* Returns "7" */

Boolean type

Boolean#to_string

Signature:

function to_string();

The to_string method returns a string representation of the boolean value.

Example:

var example = true
example.to_string() /* Returns "true" */

String type

String#find

Signature:

function find(str, start);

Returns the zero-based index at which the string str was found in the string. If the string was not found -1 is returned. start specifies the zero-based index at which find should start looking for the string (defaults to 0 when not specified).

Example:

"Hello World".find("World") /* Returns 6 */

String#len

Signature

function len();

Returns the length of the string in bytes. Note that depending on the encoding type of the string this is not necessarily the number of characters.

Example:

"Hello World".len() /* Returns 11 */

String#lower

Signature:

function lower();

Returns a copy of the string with all of its characters converted to lower-case.

Example:

"Hello World".lower() /* Returns "hello world" */

String#upper

Signature:

function upper();

Returns a copy of the string with all of its characters converted to upper-case.

Example:

"Hello World".upper() /* Returns "HELLO WORLD" */

String#replace

Signature:

function replace(search, replacement);

Returns a copy of the string with all occurences of the string specified in search replaced with the string specified in replacement.

String#split

Signature:

function split(delimiters);

Splits a string into individual parts and returns them as an array. The delimiters argument specifies the characters which should be used as delimiters between parts.

Example:

"x-7,y".split("-,") /* Returns [ "x", "7", "y" ] */

String#substr

Signature:

function substr(start, len);

Returns a part of a string. The start argument specifies the zero-based index at which the part begins. The optional len argument specifies the length of the part ("until the end of the string" if omitted).

Example:

"Hello World".substr(6) /* Returns "World" */

String#to_string

Signature:

function to_string();

Returns a copy of the string.

Array type

Array#add

Signature:

function add(value);

Adds a new value after the last element in the array.

Array#clear

Signature:

function clear();

Removes all elements from the array.

Array#clone

function clone();

Returns a copy of the array. Note that for elements which are reference values (e.g. objects such as arrays and dictionaries) only the references are copied.

Array#contains

Signature:

function contains(value);

Returns true if the array contains the specified value, false otherwise.

Array#len

Signature:

function len();

Returns the number of elements contained in the array.

Array#remove

Signature:

function remove(index);

Removes the element at the specified zero-based index.

Array#set

Signature:

function set(index, value);

Sets the element at the zero-based index to the specified value. The index must refer to an element which already exists in the array.

Array#sort

Signature:

function sort(less_cmp);

Returns a copy of the array where all items are sorted. The items are compared using the < (less-than) operator. A custom comparator function can be specified with the less_cmp argument.

Array#join

Signature:

function join(separator);

Joins all elements of the array using the specified separator.

Dictionary type

Dictionary#clone

Signature:

function clone();

Returns a copy of the dictionary. Note that for elements which are reference values (e.g. objects such as arrays and dictionaries) only the references are copied.

Dictionary#contains

Signature:

function contains(key);

Returns true if a dictionary item with the specified key exists, false otherwise.

Dictionary#len

Signature:

function len();

Returns the number of items contained in the dictionary.

Dictionary#remove

Signature:

function remove(key);

Removes the item with the specified key. Trying to remove an item which does not exist is a no-op.

Dictionary#set

Signature:

function set(key, value);

Creates or updates an item with the specified key and value.

Function type

Function#call

Signature:

function call(thisArg, ...);

Invokes the function using an alternative this scope. The thisArg argument specifies the this scope for the function. All other arguments are passed directly to the function.

Example:

function set_x(val) {
  this.x = val
}

dict = {}

set_x.call(dict, 7) /* Invokes set_x using `dict` as `this` */

Function#callv

Signature:

function callv(thisArg, args);

Invokes the function using an alternative this scope. The thisArg argument specifies the this scope for the function. The items in the args array are passed to the function as individual arguments.

Example:

function set_x(val) {
  this.x = val
}

var dict = {}

var args = [ 7 ]

set_x.callv(dict, args) /* Invokes set_x using `dict` as `this` */