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%RxFind function




Function

The function searches for the first substring that matches the specified regular expression and returns the index where the substring starts. Search is case sensitive.

Declaration
INT %RxFind(
   TEXT in Text, 
   TEXT in regExp,
   INT	in from := 1,
   INT	out endIndex
 )
Parameters
textText, which is to be searched.
regExpRegular expression that will be searched in the input parameter text.
fromIndex, from where the input parameter text will be searched (optional input parameter).
endIndexIndex in text, where the substring matching the specified regular expression ends (optional output parameter).
Example

The function returns the index, where the substring matching the specified regular expression starts. Optional parameters is endIndex. If this parameter is entered, after the function call there is stored ending index of the substring that matches the specified regular expression.

If the searching is unsuccessfull, or if the from parameter exceeds the total length of input text, the function returns 0.

If the parameter regExp is not valid regular expression, the function returns -1.

If some of the input parameters is invalid, the function returns undefined value.

 


;looking for an expression "some"
%RxFind("text some text", "some")				;returns 6

;looking for an expression "some" at the beginning
%RxFind("text some text", "^some")				;returns 0 - expression "some" is not at the beginning

;looking for an expression "text" at the beginning
%RxFind("text some text", "^text")				;returns 1 - expression "text" is at the beginning

;looking for an expression "text" at the end
%RxFind("text some text", "text$")				;returns 13 - expression "text" is at the end (starts at the position of 13)

;looking for an expression "xt" or an expression "so"
%RxFind("text some text", "xt | so")			;returns 3 - expression "xt" was found first and starts at the position of 3

;looking for an expression "some" at the beginning or the expression "text" at the end
%RxFind("text some text", "^some| text$")		;returns 12 - the entered string ends with an expression "text" and starts at the position of 12

;looking for a character in range "a-d"
%RxFind("text some text", "[a-d]")				;returns 9 - character 'a' is located on that position

;looking for a character out of range "a-d"
%RxFind("text some text", "[^a-d]")				;returns 1 - character 'a' is located on that position

;looking for 'o' character sequence 2 times in a row
%RxFind("text soome text", "e{2}")				;returns 7

;looking for an expression "oper.tor", ("." means one occurrence of any character)
%RxFind("operator operaaaator", "oper.tor")		;returns 1 - matching expression starts at this position

;looking for an expression "oper.*tor", (".*" means 0 or more occurrences of any character), while the entered string is searched from the position of 10
%RxFind("operator operaaaator", "oper.*tor", 10, _last)		;returns 10 - matching expression starts at this position, parameter _last = 20

;looking for an expression "oper.+tor", (".+" means 1 or more occurrences of any character), while the entered string is searched from the position of 10
%RxFind("operator operaaaator", "oper.+tor", 10, _last)		;returns 10 - matching expression starts at this position, parameter _last = 20

Examples of regular expressions

Regular expressionMeaning
expressionSearches for the specified expression in a string.
^expressionSearches for the specified expression at the beginning of the string.
expression$Searches for the specified expression at the end of the string.
expression1 | expression2Searches for one of the entered expressions.
^expression | expression $Searches for an expression at the beginning or end of the string.
[a-d]Searches for characters in the specified range (in this case, characters a,b,c,d).

[^a-d]

Searches for all characters except the characters in the specified range (in this case, all characters except a,b,c,d).
a{5}Searches for 'a' character sequence 5 times in a row.
oper.tor

Searches for "oper.tor", where . is replaced with occurrence of any single character (finds expressions like operator, operxtor, ...).

oper.*torSearches for "oper.*tor", where .* is replaced with 0 or more occurrences of any character (finds expressions like opertor, operator, operaaaaator, ...).
oper.+torSearches for "oper.+tor", where .+ is replaced with 1 or more occurrences of any character (does not find expression opertor).
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