Regular Expressions with OLE and Regular Expression Object
Keywords: regular expressions regular expression object OLE
This script uses a regular expression pattern to find and return the first match for the pattern in a WIL variable. It is an example that shows how the Windows regular expression capability can be used from WinBatch.; Author: Jim Stiles 20020628 GoSub UserDefinedFunctions ; Initialize the regular expression function. ; The function is SimpleRegEx(myString,myExpression,ignoreCase). ; myString can be any variable. myExpression is a regular expression pattern. ; ignoreCase is logical @TRUE or @FALSE. myString = "myabCthis is the second myabcthing" ; String with several possible matches for the expression pattern. myExpression = "a.*?c" ; match from the first a to and including the next c. To exclude the c, try [^c]* in place of .*? . ; A regular expression pattern. .* signifies match any number of characters. ; The ? finds only the first match. Without it, the pattern would be "greedy" ; The greedy match is "abCthis is the second myabc". This is usually an error. ; A list of common expressions is at the end of this script. ignoreCase = @FALSE ; Default is to test for case in string text. Set to @TRUE to ignore case. ; To select the string from the first a to the first c, use the ?. ; Without the ?, the expression would select a string from the first a to the final, and third, c. myReturn = SimpleRegEx(myString,myExpression,ignoreCase) foundStr = ItemExtract(1,myReturn,@TAB) foundPos = ItemExtract(2,myReturn,@TAB) foundLen = ItemExtract(3,myReturn,@TAB) myText = StrCat("Source string => ",myString,@CR,"Search pattern => ",myExpression," (note the case of the c)",@CR) myText = StrCat(myText,"Found string => ",foundStr,@CR,"String Start => ",foundPos,@CR) myText = StrCat(myText,"String Length => ", foundlen) Message("Results", myText) :cancel ; Used in all WIL scripts to handle dialog box cancel actions by a user. Exit ; End of the script. ;;;;;;;;;;;;;;;;;;;;;;;;;;;;; END OF SCRIPT ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; User Defined Function Section :UserDefinedFunctions #DefineFunction SimpleRegEx(myString,myExpression,ignoreCase) regex = ObjectOpen("VBScript.RegExp") ; Creates a regular expression object for use by WinBatch. regex.Pattern = myExpression ; Required to establish a regular expression pattern to use in searching. regex.IgnoreCase = ignoreCase ; Optional, but required by this user defined function. If regex.Test(myString) == 0 ; Set default return values if search string was not found. index = -1 position = 0 value = "" length = -1 GoTo finish EndIf objCollection = regex.Execute(myString) ; This initiates the object collection of the regular expression object. (!) henum = ObjectCollectionOpen(objCollection) ; OK. Start match = ObjectCollectionNext(henum) index = match.FirstIndex ; 0 based index. Note that WIL variables are indexed at 1. Arrays are indexed at 0. position = index + 1 value = match.Value length = match.Length :finish list = StrCat(value,@TAB,position,@TAB,length) ; Position is the normal WIL use based on 1 as the first character. ObjectCollectionClose(henum) ObjectClose(regex) Return list #EndFunction Return ;------------------------ Common Regular Expressions ---------------------- ;|||||||||||||||||| Text Spaces Numbers ;Patterns can include any letters, spaces, and numbers. Punctuation characters, however, are used differently. ; ;|||||||||||||||||| Punctuation and Special Characters ;Regular expressions reserve punctuation characters for special uses. Several are ; identical to the wildcards used in DOS and WIL functions such as StrReplaceWild(). ; * means any number of something. -* means any number of hyphens. {n} means n times. {n,m} is n to m times. ; ? means 0 or 1 instance. ; + means one or more instances. ; . means any character except a line end or new line. ; .* stands for any number of any character. To keep a search from going to the end of data and back again, ; follow .* and .+ by a ? character. Example: use .*? instead of .* . An alternative method: Say you want to capture the string ; between two consecutive m characters. But there are 20 of these in the source string. Use m^[^m]. to do this. The ; regular expression engine will begin with the first m. Then it will find any non m characters up to the next one, ; and, this is important, it will stop there. The regular expression function returns the position and length of the ; found string. Using these, WIL can continue searching through more data. ; ; ;|||||||||||||||||| Escape Character and Special Character Codes ; Special character escape codes. Use a backslash to escape the special meaning of these punctuation characters: ; . * + $ ^ ? \ ; Examples: \. and \\ where double backslashes stand for one backslash. ; The \\ is used constantly in DOS/Windows file paths. ; ; Tabs and other special characters also have regular expression abbreviations. ; \t tab, (CRLF) DOS/Windows line end \r. A other newlines are \n. Hexidecimal equivalents can represent ; any byte. \x1A is the old DOS end of file byte. tab is \x09. For others, see WinBatch.com tech support article W13468. ; ;|||||||||||||||||| Position Markers ; ; ^ start of input string. $ end of input string. \b boundary between a word and a character not allowed in a word. ; Examples of these are underscores, periods, and spaces. \B identifies a position followed by a word character. ; (No _ underscores, no spaces, no . periods, but hyphens - are OK) ; \d any digit. \D not a digit. \n new line. \r DOS/Windows newline. \s white space. \t tab. \w word character. ; \W non word like [^A-Za-z0-9] \n recursive matching of patterns included between parentheses. ; ;|||||||||||||||||| Ranges ; [a@ge7_&0925k O] Select any of these characters. ; [^13579] Selects none of these. Example chooses no odd digits. [^@] rules out email addresses. ; Note the two uses of the ^ character. above to signify the start of data. ; [A_Za-z] upper and lower case letters. [aeiouAEIOU] all vowels. [0-9] single digit integers. ; ;|||||||||||||||||| Logical ; [x|y] selects either x or y. ;