Calling Python ogr2ogr from PHP doesn't work as expected?

Question

I have a HTML page that takes and uploaded zip file and then calls a PHP page as a form action. That PHP then calls two Python scripts in my Apache cgi-bin. The first Python script runs with no issue and simply unzips the uploaded file within a sub directory. The second Python script includes a subprocess call to a command line tool to perform some action on the unzipped files. However, I am finding that using the exec() in PHP for the second Python script with the subprocess does not work. If I run the Python script from the command line it works fine. But, if I call it from the PHP exec function it does nothing.

The snippet of PHP:

$tmp1 = exec("C:\\ms4w\\Python\\python C:\\ms4w\\Apache\\cgi-bin\\unzip_shp.py $without_extension");
echo $tmp1;
echo "<br>";
$tmp2 = exec("C:\\ms4w\\Python\\python C:\\ms4w\\Apache\\cgi-bin\\convert_to_geojson.py $without_extension", $output);
echo $output

The snippet of Python:

command = "C:\\ms4w\\tools\\gdal-ogr\\ogr2ogr.exe -f \"GeoJSON\" "+sys.argv[1]+".geojson "+sys.argv[1]+".shp" #os.system(command)
subprocess.check_call(command)
print(command)

The print command in the Python returns this to the PHP:

C:\ms4w\tools\gdal-ogr\ogr2ogr.exe -f "GeoJSON" C:\ms4w\Apache\htdocs\uploads\parks_escambia.geojson C:\ms4w\Apache\htdocs\uploads\parks_escambia.shp

Also, I am running this all on a Windows OS as a localhost development server. Using Python version 2.7.

Answer 1

You may need to set some of GDAL's environmental variables when you run subprocess, such as GDAL_DATA.

You can see which are being set in the MS4W setenv.bat script.