Configuration with options or environment variables

Floris Vanderhaeghe

Last update: 2024-06-28
Last run: 2024-10-07

Options and environment variables are available to manage qgisprocess behaviour. Several options have a corresponding environment variable. When both have a value, the option will be given priority.

Options are typically harder to isolate from the R code that you collaborate on. Consequently, it is advised to:

• use options() where this affects behaviour that must be the same across users and machines for reproducibility. Put these inside your script, or at least in a .Rprofile file that is shared together with the other project files.
• use environment variables where behaviour must be machine-specific. For example, you can create a .Renviron file in your working directory and ignore it in distributed version control. Or you can set the environment variable at a higher level, e.g. in a .Renviron file in your home directory. See base::Startup for more information.

Overview

Below table lists the available options and environment variables.

Option	Environment variable	Type
qgisprocess.path	R_QGISPROCESS_PATH	string (filepath)
qgisprocess.tmp_vector_ext	not available	string (file extension)
qgisprocess.tmp_raster_ext	not available	string (file extension)
qgisprocess.detect_newer_qgis	R_QGISPROCESS_DETECT_NEWER_QGIS	logical
qgisprocess.use_json_input	R_QGISPROCESS_USE_JSON_INPUT	logical
qgisprocess.use_json_output	R_QGISPROCESS_USE_JSON_OUTPUT	logical
qgisprocess.cachefiles_days_keep	R_QGISPROCESS_CACHEFILES_DAYS_KEEP	numeric
qgisprocess.use_cached_help	R_QGISPROCESS_USE_CACHED_HELP	logical
qgisprocess.env	not available	named list

Descriptions

Following descriptions are applicable to both option and environment variable:

• qgisprocess.path: sets the path to ‘qgis_process’; see qgis_configure()
• qgisprocess.tmp_vector_ext: sets the vector file extension for temporary files; see qgis_tmp_vector()
• qgisprocess.tmp_raster_ext: sets the raster file extension for temporary files; see qgis_tmp_raster()
• qgisprocess.detect_newer_qgis: for Windows and macOS; will report availability of an installed (standalone) QGIS version that is more recent than the cached version
• qgisprocess.use_json_input: control whether the JSON input method is used; see qgis_using_json_input()
• qgisprocess.use_json_output: control whether the JSON output method is used; see qgis_using_json_output()
• qgisprocess.cachefiles_days_keep: control a cache file’s age (as days) that must be exceeded for it to be deleted when loading the package (default is 90); see ?qgis_delete_old_cachefiles
• qgisprocess.use_cached_help: whether to fetch an algorithm’s documentation from a cached file (corresponding to the QGIS and qgisprocess versions in use) if this file exists (default is TRUE; if FALSE, always (re)query documentation from QGIS)
• qgisprocess.env: named list of environment variable values used in each call to ‘qgis_process’; see qgis_run()