Evaluation functions

Use the evaluation functions to evaluate an expression, based on your events, and return a result.

Quick reference

See the Supported functions and syntax section for a quick reference list of the evaluation functions.

Commands

You can use evaluation functions with the eval, fieldformat, and where commands, and as part of eval expressions with other commands.

Usage

All functions that accept strings can accept literal strings or any field.
All functions that accept numbers can accept literal numbers or any numeric field.

String arguments and fields

For most evaluation functions, when a string argument is expected, you can specify either a literal string or a field name. Literal strings must be enclosed in double quotation marks. In other words, when the function syntax specifies a string you can specify any expression that results in a string. For example, you have a field called name which contains the names of your servers. You want to append the literal string server at the end of the name. You would specify this: name + "server".

Nested functions

You can specify a function as an argument to another function.

In the following example, the cidrmatch function is used as the first argument in the if function.

... | eval isLocal=if(cidrmatch("123.132.32.0/25",ip), "local", "not local")

The following example shows how to use the true() function to provide a default to the case function.

... | eval error=case(status == 200, "OK", status == 404, "Not found", true(), "Other")

Supported functions and syntax

There are two ways that you can see information about the supported evaluation functions:

Function list by category
Alphabetical list of functions

Function list by category

The following table is a quick reference of the supported evaluation functions. This table lists the syntax and provides a brief description for each of the functions. Use the links in the Type of function column for more details and examples.

Type of function	Supported functions and syntax	Description
Comparison and Conditional functions	`case(X,"Y",...)`	Accepts alternating conditions and values. Returns the first value for which the condition evaluates to TRUE.
	`cidrmatch("X",Y)`	Returns TRUE or FALSE based on whether an IP address matches a CIDR notation.
	`coalesce(X,...)`	This function takes an arbitrary number of arguments and returns the first value that is not NULL.
	`false()`	Returns FALSE.
	`if(X,Y,Z)`	If the condition X evaluates to TRUE, returns Y, otherwise returns Z.
	`in(FIELD, VALUE-LIST)`	The function returns TRUE if one of the values in the list matches a value in the field you specify.
	`like(TEXT, PATTERN)`	Returns TRUE if TEXT matches PATTERN.
	`match(SUBJECT, "REGEX")`	Returns TRUE or FALSE based on whether REGEX matches SUBJECT
	`null()`	This function takes no arguments and returns NULL.
	`nullif(X,Y)`	This function is used to compare fields. The function takes two arguments, X and Y, and returns NULL if X = Y. Otherwise it returns X.
	`searchmatch(X)`	Use this function to return TRUE if the search string (X) matches the event.
	`true()`	Returns TRUE.
	`validate(X,Y,...)`	Use this function to return the string Y corresponding to the first expression X that evaluates to FALSE. This function is the opposite of the `case` function.
Conversion functions	`printf("format",arguments)`	Creates a formatted string based on a format description that you provide.
	`tonumber(NUMSTR,BASE)`	Converts a string to a number.
	`tostring(X,Y)`	Converts the input, such as a number or a Boolean value, to a string.
Cryptographic functions	`md5(X)`	Computes the md5 hash for the value X.
	`sha1(X)`	Computes the sha1 hash for the value X.
	`sha256(X)`	Computes the sha256 hash for the value X.
	`sha512(X)`	Computes the sha512 hash for the value X.
Date and Time functions	`now()`	Returns the time that the search was started.
	`relative_time(X,Y)`	Adjusts the time by a relative time specifier.
	`strftime(X,Y)`	Takes a UNIX time and renders it into a human readable format.
	`strptime(X,Y)`	Takes a human readable time and renders it into UNIX time.
	`time()`	The time that eval function was computed. The time will be different for each event, based on when the event was processed.
Informational functions	`isbool(X)`	Returns TRUE if the field value is Boolean.
	`isint(X)`	Returns TRUE if the field value is an integer.
	`isnotnull(X)`	Returns TRUE if the field value is not NULL.
	`isnull(X)`	Returns TRUE if the field value is NULL.
	`isnum(X)`	Returns TRUE if the field value is a number.
	`isstr(X)`	Returns TRUE if the field value is a string.
	`typeof(X)`	Returns a string that indicates the field type, such as Number, String, Boolean, and so forth
Mathematical functions	`abs(X)`	Returns the absolute value.
	`ceiling(X)` or `ceil(X)`	Rounds the value up to the next highest integer.
	`exact(X)`	Returns the result of a numeric eval calculation with a larger amount of precision in the formatted output.
	`exp(X)`	Returns the exponential function `e^X`.
	`floor(X)`	Rounds the value down to the next lowest integer.
	`ln(X)`	Returns the natural logarithm.
	`log(X,Y)`	Returns the logarithm of X using Y as the base. If Y is omitted, base 10 is used.
	`pi()`	Returns the constant `pi` to 11 digits of precision.
	`pow(X,Y)`	Returns X to the power of Y, `X^Y`.
	`round(X,Y)`	Returns X rounded to the amount of decimal places specified by Y. The default is to round to an integer.
	`sigfig(X)`	Rounds X to the appropriate number of significant figures.
	`sqrt(X)`	Returns the square root of the value.
Multivalue eval functions	`commands(X)`	Returns a multivalued field that contains a list of the commands used in X.
	`mvappend(X,...)`	Returns a multivalue result based on all of values specified.
	`mvcount(MVFIELD)`	Returns the count of the number of values in the specified field.
	`mvdedup(X)`	Removes all of the duplicate values from a multivalue field.
	`mvfilter(X)`	Filters a multivalue field based on an arbitrary Boolean expression X.
	`mvfind(MVFIELD,"REGEX")`	Finds the index of a value in a multivalue field that matches the REGEX.
	`mvindex(MVFIELD,STARTINDEX,ENDINDEX)`	Returns a set of values from a multivalue field described by STARTINDEX and ENDINDEX.
	`mvjoin(MVFIELD,STR)`	Takes all of the values in a multivalue field and appends them together delimited by STR.
	`mvrange(X,Y,Z)`	Creates a multivalue field with a range of numbers between X and Y, incrementing by Z.
	`mvsort(X)`	Returns the values of a multivalue field sorted lexicographically.
	`mvzip(X,Y,"Z")`	Takes two multivalue fields, X and Y, and combines them by stitching together the first value of X with the first value of field Y, then the second with the second, and so on.
	`split(X,"Y")`	Returns a mv field splitting X by the delimited character Y.
Statistical eval functions	`max(X,...)`	Returns the maximum of the string or numeric values.
	`min(X,...)`	Returns the minimum of the string or numeric values.
	`random()`	Returns a pseudo-random integer ranging from zero to 2³¹-1.
Text functions	`len(X)`	Returns the count of the number of characters (not bytes) in the string.
	`lower(X)`	Converts the string to lowercase.
	`ltrim(X,Y)`	Trims the characters represented in Y from the left side of the string.
	`replace(X,Y,Z)`	Returns a string formed by substituting string Z for every occurrence of regex string Y in string X.
	`rtrim(X,Y)`	Returns X with the characters in Y trimmed from the right side.
	`spath(X,Y)`	Extracts a value from a structured data type (XML or JSON) in X based on a location path in Y.
	`substr(X,Y,Z)`	Returns a substring from X based on the starting position Y and the length Z.
	`trim(X,Y)`	Trims the characters represented in Y from both sides of the string X.
	`upper(X)`	Returns the string in uppercase.
	`urldecode(X)`	Replaces URL escaped characters with the original characters.
Trigonometry and Hyperbolic functions	`acos(X)`	Computes the arc cosine of X.
	`acosh(X)`	Computes the arc hyperbolic cosine of X.
	`asin(X)`	Computes the arc sine of X.
	`asinh(X)`	Computes the arc hyperbolic sine of X.
	`atan(X)`	Computes the arc tangent of X.
	`atan2(X,Y)`	Computes the arc tangent of X,Y.
	`atanh(X)`	Computes the arc hyperbolic tangent of X.
	`cos(X)`	Computes the cosine of an angle of X radians.
	`cosh(X)`	Computes the hyperbolic cosine of X radians.
	`hypot(X,Y)`	Computes the hypotenuse of a triangle.
	`sin(X)`	Computes the sine of X.
	`sinh(X)`	Computes the hyperbolic sine of X.
	`tan(X)`	Computes the tangent of X.
	`tanh(X)`	Computes the hyperbolic tangent of X.

Alphabetical list of functions

Supported functions and syntax	Description	Type of function
`abs(X)`	Returns the absolute value.	Mathematical functions
`acos(X)`	Computes the arc cosine of X.	Trigonometry and Hyperbolic functions
`acosh(X)`	Computes the arc hyperbolic cosine of X.	Trigonometry and Hyperbolic functions
`asin(X)`	Computes the arc sine of X.	Trigonometry and Hyperbolic functions
`asinh(X)`	Computes the arc hyperbolic sine of X.	Trigonometry and Hyperbolic functions
`atan(X)`	Computes the arc tangent of X.	Trigonometry and Hyperbolic functions
`atan2(X,Y)`	Computes the arc tangent of X,Y.	Trigonometry and Hyperbolic functions
`atanh(X)`	Computes the arc hyperbolic tangent of X.	Trigonometry and Hyperbolic functions
`case(X,"Y",...)`	Accepts alternating conditions and values. Returns the first value for which the condition evaluates to TRUE.	Comparison and Conditional functions
`cidrmatch("X",Y)`	Returns TRUE or FALSE based on whether an IP address matches a CIDR notation.	Comparison and Conditional functions
`ceiling(X)`	Rounds the value up to the next highest integer.	Mathematical functions
`coalesce(X,...)`	This function takes an arbitrary number of arguments and returns the first value that is not NULL.	Comparison and Conditional functions
`commands(X)`	Returns a multivalued field that contains a list of the commands used in X.	Multivalue eval functions
`cos(X)`	Computes the cosine of an angle of X radians.	Trigonometry and Hyperbolic functions
`cosh(X)`	Computes the hyperbolic cosine of X radians.	Trigonometry and Hyperbolic functions
`exact(X)`	Returns the result of a numeric eval calculation with a larger amount of precision in the formatted output.	Mathematical functions
`exp(X)`	Returns the exponential function `e^X`.	Mathematical functions
`false()`	Returns FALSE.	Comparison and Conditional functions
`floor(X)`	Rounds the value down to the next lowest integer.	Mathematical functions
`hypot(X,Y)`	Computes the hypotenuse of a triangle.	Trigonometry and Hyperbolic functions
`if(X,Y,Z)`	If the condition X evaluates to TRUE, returns Y, otherwise returns Z.	Comparison and Conditional functions
`in(FIELD, VALUE-LIST)`	The function returns TRUE if one of the values in the list matches a value in the field you specify.	Comparison and Conditional functions
`isbool(X)`	Returns TRUE if the field value is Boolean.	Informational functions
`isint(X)`	Returns TRUE if the field value is an integer.	Informational functions
`isnotnull(X)`	Returns TRUE if the field value is not NULL.	Informational functions
`isnull(X)`	Returns TRUE if the field value is NULL.	Informational functions
`isnum(X)`	Returns TRUE if the field value is a number.	Informational functions
`isstr(X)`	Returns TRUE if the field value is a string.	Informational functions
`len(X)`	Returns the count of the number of characters (not bytes) in the string.	Text functions
`like(TEXT, PATTERN)`	Returns TRUE if TEXT matches PATTERN.	Comparison and Conditional functions
`ln(X)`	Returns the natural logarithm.	Mathematical functions
`log(X,Y)`	Returns the logarithm of X using Y as the base. If Y is omitted, base 10 is used.	Mathematical functions
`lower(X)`	Converts the string to lowercase.	Text functions
`ltrim(X,Y)`	Trims the characters represented in Y from the left side of the string.	Text functions
`match(SUBJECT, "REGEX")`	Returns TRUE or FALSE based on whether REGEX matches SUBJECT.	Comparison and Conditional functions
`max(X,...)`	Returns the maximum of the string or numeric values.	Statistical eval functions
`md5(X)`	Computes the md5 hash for the value X.	Cryptographic functions
`min(X,...)`	Returns the minimum of the string or numeric values.	Statistical eval functions
`mvappend(X,...)`	Returns a multivalue result based on all of values specified.	Multivalue eval functions
`mvcount(MVFIELD)`	Returns the count of the number of values in the specified field.	Multivalue eval functions
`mvdedup(X)`	Removes all of the duplicate values from a multivalue field.	Multivalue eval functions
`mvfilter(X)`	Filters a multivalue field based on an arbitrary Boolean expression X.	Multivalue eval functions
`mvfind(MVFIELD,"REGEX")`	Finds the index of a value in a multivalue field that matches the REGEX.	Multivalue eval functions
`mvindex(MVFIELD,STARTINDEX,ENDINDEX)`	Returns a set of values from a multivalue field described by STARTINDEX and ENDINDEX.	Multivalue eval functions
`mvjoin(MVFIELD,STR)`	Takes all of the values in a multivalue field and appends them together delimited by STR.	Multivalue eval functions
`mvrange(X,Y,Z)`	Creates a multivalue field with a range of numbers between X and Y, incrementing by Z.	Multivalue eval functions
`mvsort(X)`	Returns the values of a multivalue field sorted lexicographically.	Multivalue eval functions
`mvzip(X,Y,"Z")`	Takes two multivalue fields, X and Y, and combines them by stitching together the first value of X with the first value of field Y, then the second with the second, and so on.	Multivalue eval functions
`now()`	Returns the time that the search was started.	Date and Time functions
`null()`	This function takes no arguments and returns NULL.	Comparison and Conditional functions
`nullif(X,Y)`	This function is used to compare fields. The function takes two arguments, X and Y, and returns NULL if X = Y. Otherwise it returns X.	Comparison and Conditional functions
`pi()`	Returns the constant `pi` to 11 digits of precision.	Mathematical functions
`pow(X,Y)`	Returns X to the power of Y, `X^Y`.	Mathematical functions
`printf("format",arguments)`	Creates a formatted string based on a format description that you provide.	Conversion functions
`random()`	Returns a pseudo-random integer ranging from zero to 2³¹-1.	Statistical eval functions
`relative_time(X,Y)`	Adjusts the time by a relative time specifier.	Date and Time functions
`replace(X,Y,Z)`	Returns a string formed by substituting string Z for every occurrence of regex string Y in string X.	Text functions
`round(X,Y)`	Returns X rounded to the amount of decimal places specified by Y. The default is to round to an integer.	Mathematical functions
`rtrim(X,Y)`	Returns X with the characters in Y trimmed from the right side.	Text functions
`searchmatch(X)`	Use this function to return TRUE if the search string (X) matches the event.	Comparison and Conditional functions
`sha1(X)`	Computes the sha1 hash for the value X.	Cryptographic functions
`sha256(X)`	Computes the sha256 hash for the value X.	Cryptographic functions
`sha512(X)`	Computes the sha512 hash for the value X.	Cryptographic functions
`sigfig(X)`	Rounds X to the appropriate number of significant figures.	Mathematical functions
`sin(X)`	Computes the sine of X.	Trigonometry and Hyperbolic functions
`sinh(X)`	Computes the hyperbolic sine of X.	Trigonometry and Hyperbolic functions
`spath(X,Y)`	Extracts a value from a structured data type (XML or JSON) in X based on a location path in Y.	Text functions
`split(X,"Y")`	Returns a mv field splitting X by the delimited character Y.	Multivalue eval functions
`sqrt(X)`	Returns the square root of the value.	Mathematical functions
`strftime(X,Y)`	Takes a UNIX time and renders it into a human readable format.	Date and Time functions
`strptime(X,Y)`	Takes a human readable time and renders it into UNIX time.	Date and Time functions
`substr(X,Y,Z)`	Returns a substring from X based on the starting position Y and the length Z.	Text functions
`tan(X)`	Computes the tangent of X.	Trigonometry and Hyperbolic functions
`tanh(X)`	Computes the hyperbolic tangent of X.	Trigonometry and Hyperbolic functions
`time()`	The time that eval function was computed. The time will be different for each event, based on when the event was processed.	Date and Time functions
`tonumber(NUMSTR,BASE)`	Converts a string to a number.	Conversion functions
`tostring(X,Y)`	Converts the input, such as a number or a Boolean value, to a string.	Conversion functions
`trim(X,Y)`	Trims the characters represented in Y from both sides of the string X.	Text functions
`true()`	Returns TRUE.	Comparison and Conditional functions
`typeof(X)`	Returns a string that indicates the field type, such as Number, String, Boolean, and so forth.	Informational functions
`upper(X)`	Returns the string in uppercase.	Text functions
`urldecode(X)`	Replaces URL escaped characters with the original characters.	Text functions
`validate(X,Y,...)`	Use this function to return the string Y corresponding to the first expression X that evaluates to FALSE. This function is the opposite of the `case` function.	Comparison and Conditional functions

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Related Answers

Evaluation functions

Quick reference

Commands

Usage

String arguments and fields

Nested functions

Supported functions and syntax

Function list by category

Alphabetical list of functions

See also

Comments

Evaluation functions