CFLib.org – Common Function Library Project

Description:
Takes a file path and a comma-separated list of three-letter extensions. Returns TRUE if there's a three-letter extension that matches one in the list, otherwise FALSE. Can be tweaked to accept 4-letter extensions.

Return Values:
Returns a boolean.

Example:

<cfset path1="d:\docs\letter.doc">
<cfset path2="c:\blah.exe">
<cfset path3="d:\images\pic.tiff">
<cfset path4="d:\images\macImage">

<cfoutput>
path1 (#path1#) valid? #YesNoFormat(IsExtValid(path1, "doc,txt,pdf"))#<br />
path2 (#path2#) valid? #YesNoFormat(IsExtValid(path2, "doc,txt,pdf"))#<br />
path3 (#path3#) valid? #YesNoFormat(IsExtValid(path3, "doc,txt,pdf"))#<br />
path4 (#path4#) valid? #YesNoFormat(IsExtValid(path4, "doc,txt,pdf"))#<br />
</cfoutput>

Parameters:

Full UDF Source:

<cfscript>
/**
 * Checks for a valid file extension.
 * 
 * @param path 	 The file path. 
 * @param extlist 	 The list of valid extensions. 
 * @return Returns a boolean. 
 * @author Gyrus (&#103;&#121;&#114;&#117;&#115;&#50;&#51;&#64;&#104;&#111;&#116;&#109;&#97;&#105;&#108;&#46;&#99;&#111;&#109;) 
 * @version 1, December 19, 2001 
 */
function IsExtValid(path,extlist) {
	// Find the last dot
	var DotPos = Find(".", Reverse(path));
	// Grab the extension
	var ext = Right(path, 3);
        return (not ((DotPos NEQ 4) OR (NOT ListFindNoCase(extlist, ext))));
}
</cfscript>