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ColdFusion Tip: How to tell if path is file or directory

Today, one of the ColdFusion users asked me a question "Is there anyway I can find out whether a path is a directory or a file? There is no isDirectory() function available in ColdFusion and I don't want to write Java code to do this. Any help?"
For a moment I thought really! is there no way that ColdFusion can tell you whether a given path is of a directory or file? But sooner, I came across the function 'getFileInfo' which takes the path as an argument and returns a struct data that contains various metadata properties of the file. The struct includes a key - 'type' whose value can either be a directory or file. The below code shows how you can determine whether the given path is of a directory or file:

<cfset fileInfo = getFileInfo(expandPath("./myDir")) > <cfif fileInfo.type EQ "directory"> <!--- is a directory ---> <cfelseif fileInfo.type EQ "file"> <!--- is a file ---> </cfif> <cfdump var="#fileInfo#">

The other metadata properties such as canRead, canWrite, isHidden, lastModified, parent, size included in the resultant struct can also come handy.

Comments

  1. Could probably just use DirectoryExists() as well. I believe that would return false if it's a regular file.

    ReplyDelete
    Replies
    1. @Matt,
      DirectoryExists() is a nice function, but it is used to check whether a directory\path exists. It would return true only when the given directory is found and would return false if not found.

      <cfoutput>#directoryExists(expandPath("./dirExists"))#</cfoutput> <!--- returns true\yes --->
      <cfoutput>#directoryExists(expandPath("./dirDoesntExist"))#</cfoutput> <!--- returns false\no --->

      Of course, it would return false if you mention a file name, but assuming that it returns false only for the file names wouldn't be right.

      On the other hand getFileInfo() gives you the right data(file\directory).

      Delete
    2. Matt is assuming you know the resource exists and simply want to discover it's type.

      If you don't know whether it exists and need to know the type (i.e. extra info is irrelevant), you can just do DirectoryExists and FileExists in combo:







      Of course, it's also worth pointing out that if you've done a cfdirectory you've already got this info available from the query returned by that (and from CF8 onwards can filter it with the type attribute).

      Delete
    3. It's 2012 and there's *still* buggy blog software incapable of handling angle brackets. :/

      Here's what the gap in the middle of the above comment should be:

      <cffunction name="getPathType" output="false" returntype="string">
      <cfargument name="Path" type="String" required />
      <cfreturn DirectoryExists( Arguments.Path )
      ? "dir"
      : FileExists( Arguments.Path )
      ? "file"
      : ""
      />
      </cffunction>

      Delete
    4. @Peter,
      You're right, that's another way of doing it. However, I find getFileInfo('path').type as an easy way to determine whether the resource is a file or directory. If an assumption is made that the resource exists then DirectoryExists() would suffice. I wouldn't use two functions to determine the resource type.

      Delete
  2. Nice tip, Sagar. I use GetFileInfo quite a lot, but never thought to apply it to a directory.

    ReplyDelete
  3. I found interesting case study paper about it.Few do actually understand these things, and many who don't understand will jump too readily into aggressive postures against the people trying to run the schools and teach the children.


    ReplyDelete

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