[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: C: in ncml

This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.

  • Subject: Re: C: in ncml
  • Date: Thu, 09 Aug 2007 08:56:20 -0600

Ethan Davis wrote:

John Caron wrote:

Allowable forms of the referenced dataset location are:

   * an absolute HTTP URL (eg http://server/myfile.nc)
* An absolute file URL with an absolute path (eg file:/usr/local/data/mine.nc). You can sometimes omit the file: prefix, but not always, so we recommend using the file: prefix.
What does that second sentence above mean? Can we just drop that sentence? As it is, seems like it will cause more confusion than it is worth. Also, seems like it would conflict with the item two bullets down (a URL relative to the NcML document base). 

Is it even a file URL if it doesn't have the "file:" prefix?


in the absence of a file prefix, i think it will try it as a file if all else fails. The 
C: interferes, since it makes it look like a URL with schema "C"
* An absolute file URL with a relative path (eg file:data/mine.nc). The file will be opened reletive to the working directory.
Is this a valid file URL? In Java I can get a URL and URI for this string. But it fails when I try to get a File. I hate to document the use of a form of file URL that isn't a good file URL. 

im not sure if thats standard usage, since "file:" is particularly ill-defined 
("opaque"). Its quite useful when you want the NcML to refer to a file in the same 
directory.
* A relative URL resolved against the NcML location (eg subdir/mydata.nc). You must not use a file: prefix in this case. 

Ethan




http://www.unidata.ucar.edu/software/netcdf-java/reference/DatasetUrls.html#NcML

has been modified. any further suggestions welcome