How to edit the GDAL/OGR console call in QGIS 3.0?

Question

In QGIS 2.XX, the drop-down menu bar tools had an editable call box at the bottom, where commands not available in the gui could be manually entered (by clicking a pencil button). In 3.0, the menu bar tools are the same as the GDAL tools found in the processing toolbox, which makes more sense, but now I do not see a way to add simple commands to a tool operation. The example I attach is the warp (reproject) tool, I wish to add the command "-wo CUTLINE_ALL_TOUCHED=TRUE". How do I do that?

Answer 1

This can be done using Python console.

First copy (or write) a GDAL command and edit in a text viewer. For instance: gdaldem hillshade C:/MyInputFile.tif C:/MyOutputFile.tif -of GTiff -b 1 -z 1.0 -s 1.0 -az 315.0 -alt 45.0 -multidirectional, where we need to delete -az 315.0 (cannot do it in the interface...)

Then open the Python console and type:

import subprocess

cmd = "gdaldem hillshade C:/MyInputFile.tif C:/MyOutputFile.tif -of GTiff -b 1 -z 1.0 -s 1.0 -alt 45.0 -multidirectional"

subprocess.run ([x for x in cmd.split(" ") if x != ""])

Command cmd has to be enclosed with quotation marks " ". Note that you will need to load manually the created file.

I agree that disabling editing of gdal commands is a retrograde step - hope it gets implemented in future versions.

Answer 2

Disappointing that you can't edit GDAL commands easily in latest QGIS. One option is to use the OSGeo4W shell that installs along with QGIS. You can use that to run GDAL commands directly.

Answer 3

A simple and easy to follow user guide for installing GDAL by UCLA Installing GDAL for Windows It is great for running custom GDAL straight from the command prompt.

Answer 4

A way to do it is to run a dummy command with most of the parameter that you want to keep and then check the history of your processing toolbox. You will find a line like the one below:

processing.run("gdal:warpreproject", {'INPUT':'C:/Users/XXXXX/DTM_300X.tif','SOURCE_CRS':QgsCoordinateReferenceSystem('EPSG:300X'),'TARGET_CRS':QgsCoordinateReferenceSystem('EPSG:300Y'),'RESAMPLING':0,'NODATA':None,'TARGET_RESOLUTION':None,'OPTIONS':'','DATA_TYPE':0,'TARGET_EXTENT':None,'TARGET_EXTENT_CRS':None,'MULTITHREADING':False,'EXTRA':'','OUTPUT':'C:/Users/XXXXX/DTM_300Y.tif'})

You can copy and paste it in in an text editor for your modification and once it is ready, you can run it in the Python console of QGIS.

Would it be 'OPTIONS':'-wo'? I did not try it