CFLib.org – Common Function Library Project

Description:
Paths can be system path (C:\myroot\mydir\myfile.cfm) or url (http://www.mydomain/myfile.cfm) but different kinds of paths (system and url) can't be used at the very same time.

Return Values:
Returns a string.

Example:

<cfoutput>
relativeFilePath("C:\myroot\mydir\myfile.cfm", "C:\myroot\mydir\mySubdir\myfile.cfm") =
#relativeFilePath("C:\myroot\mydir\myfile.cfm", "C:\myroot\mydir\mySubdir\myfile.cfm")#
</cfoutput>

Parameters:

Full UDF Source:

/**
 * Calculate the relative path from startFile to endFile.
 * when two
 * Ver 1.1 fixes a minor bug when multiple files are located inside the same directory and their names start with the same letter.
 * 
 * @param startFile      First file. (Required)
 * @param endFile      Second file. (Required)
 * @return Returns a string. 
 * @author Massimo Foti (massimo@massimocorner.com) 
 * @version 1.1, May 19, 2003 
 */
function relativeFilePath(startFile,endFile){
    //In case we have absolute local paths, turn backward to forward slashes
    var startpath = Replace(startFile,"\","/","ALL"); 
    var endPath = Replace(endFile,"\","/","ALL"); 
    //Declare variables
    var i = 1;
    var j = 1;
    var endStr = "";
    var commonStr = "";
    var retVal = "";
    var whatsLeft = "";
    var slashPos = "";
    var slashCount = 0;
    var dotDotSlash = "";
    //Be sure the paths aren't equal
    if(startpath NEQ endPath){
        //If the starting path is longer, the destination path is our starting point
        if(len(startpath) GT len(endPath)){
            endStr = len(endPath);
        }
        //Else the starting point is the start path
        else{
            endStr = len(startpath);
        }
        //Check if the two paths share a base path and store it into the commonStr variable
        for(i;i LT endStr; i=i+1){
            //Compare one character at time
            if(mid(startpath,i,1) EQ mid(endPath,i,1)){
                commonStr = commonStr & mid(startpath,i,1);
            }
            else{
                break;
            }
        }
        //We just need the base directory
        commonStr=REReplaceNoCase(commonStr,"[^/]*$","");
        //If there is a common base path, remove it
        if(len(commonStr) GT 0){
            whatsLeft = mid(startpath,len(commonStr)+1,len(startpath));
        }
        else{
            whatsLeft = startpath;
        }
        slashPos = find("/",startpath);
        //Count how many directories we have to climb
        while(slashPos NEQ 0){
            slashCount = slashCount + 1;
            slashPos = find("/",whatsLeft,slashPos+1);
        }
        //Append "../" for each directory we have to climb
        for(j;j LT slashCount; j=j+1){
            dotDotSlash = dotDotSlash & "../";
        }
        //Assemble the final path
        retVal = dotDotSlash & mid(endPath,len(commonStr)+1,len(endPath));
    }
    //Paths are the same
    else{
        retVal = "";
    }
    return retVal;
}