gdal_vrtmerge.py vs. gdalbuildvrt

Question

In the gdalbuildvrt documentation, I read

This utility is somehow equivalent to the gdal_vrtmerge.py utility [...]

So what is the difference (if any) between gdalbuildvrt and gdal_vrtmerge.py?

What does "somehow equivalent" mean here?

1. Is one an alias for the other?

2. Do they have the same command line interface? (I.e., do they accept the same parameters and options, and do so with the same semantics?)

   (It seems so.)

3. Did one replace or deprecate the other?
4. Should one be preferred over the other?

And where can I find more information about gdal_vrtmerge.py? It doesn't seem to be included in my GDAL installation, but it's in the GDAL sources at gdal/swig/python/samples/gdal_vrtmerge.py (download | view on trac) on trunk.

Answer 1

The Python script is older but the executable is not an exact rewrite in C++. As you can see from the history the latest real change to the gdal_vrtmerge was done about 7 years ago in revision 20672.

1) Not exactly, but probably gdalbuildvrt was close to gdal_vrtmerge.py in GDAL 1.6 many years ago.

2) Probably, but not guaranteed because they are not developed hand in hand.

3) gdalbuildvrt is obviously written for a reason but the Python script still works.

4) The only reason that I see for using the Python version is that it is easier to modify to suit for some special purpose because it is Python and not C++.