Symbolic Path

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When files are located beneath certain special folders, callers that link to these files will link to them using a symbolic path, rather than an absolute or relative path. The symbolic path will be relative to the special folder. The following table lists these special folders and their symbolic path:

symbolic path description actual path
<userlib> User Libraries <LabVIEW>\user.lib
<vilib> NI Libraries and Addons <LabVIEW>\vi.lib
<instrlib> Instrument Drivers <LabVIEW>\instr.lib
<help> Help Files <LabVIEW>\help
<osdatadir> Default file directory of the operating system (OS Dependent)
<menu> Palette Menus <LabVIEW>\menus

Note that some of these can have the actual path changed by changing the settings in Tools>>Options. The whole point of the symbolic path is to indicate "load from whatever location this path is currently defined to be."

For example, if you have a VI located in the following location:

<LabVIEW>\user.lib\_OpenG.lib\array\array.llb\Conditional Auto-Indexing Tunnel__ogtk.vi

Callers will link to this VI using the following symbolic path:

<userlib>\_OpenG.lib\array\array.llb\Conditional Auto-Indexing Tunnel__ogtk.vi

symbolic path are not generally encountered. They are used mostly under the hood of LabVIEW, for example, when using the Application Linker:Read Info From File and Linker:Write Info To File methods.

Resolving Symbolic Paths Programmatically

You can call the private Resolve Symbolic Path method to convert a Symbolic Path to an absolute path, as shown in the screenshot, below.

ResolveSymbolicPath.png

Auto update of symbolic paths

If you have a VI linked to another VI inside a symbolic path LabVIEW will automatically store the path symbolically. Here's the following use case:

Suppose you want to build a LabVIEW tool that resides under the Tools menu but is also accessible via the user.lib palette. What you can do is create a set-up upon built like this:

  • [Built]
    • [Tools]
      • Menu VI
    • [user.lib]
      • Actual VI

When you copy the contents of Built to the LabVIEW folder the Menu VI will have a relative path like ..\user.lib\Actual VI when you do a resave of the Menu VI the path will be changed to an absolute path <userlib>\Actual VI. Now you can move the Menu VI around without breaking it.

When Using Modules (FPGA, RT, etc)

A symbolic path may resolve to different actual files on disk depending upon which target the VI is loaded into. So a VI that is written to use <vilib>\a.vi may use <labview>\vi.lib\a.vi when loaded for the desktop target, but may use <labview>\vi.lib\fpga\a.vi when loaded for the FPGA target.

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