+
+ +
+

Environment variables

+

PROJ can be controlled by setting environment variables. Most users will +have a use for the PROJ_LIB.

+

On UNIX systems environment variables can be set for a shell-session with:

+
$ export VAR="some variable"
+
+
+

or it can be set for just one command line call:

+
$ VAR="some variable" ./cmd
+
+
+

Environment variables on UNIX are usually removed with the unset command:

+
$ unset VAR
+
+
+

On windows systems environment variables can be set in the command line with:

+
> set VAR="some variable"
+
+
+

VAR will be available for the entire session, unless it is unset. This is +done by setting the variable with no content:

+
> set VAR=
+
+
+
+
+PROJ_LIB
+

The location of PROJ resource files.

+

Starting with PROJ 6, multiple directories can be specified. On Unix, they +should be separated by the colon (:) character. on Windows, by the semi-colon (;) +character.

+

PROJ is hardcoded to look for resource files +in other locations as well, amongst those are the +installation directory (usually share/proj under the PROJ +installation root) and the current folder.

+

You can also set the location of the resource files using +proj_context_set_search_paths() in the proj.h API header.

+
+ +
+

Changed in version 6.1.0: Starting with PROJ version 6.1.0, the paths set by +proj_context_set_search_paths() will have priority over the +PROJ_LIB to allow for multiple versions of PROJ +resource files on your system without conflicting.

+
+
+
+PROJ_AUX_DB
+
+

New in version 8.1.0.

+
+

To set the path to one or several auxiliary SQLite3 databases of structure +identical to the main proj.db database and that can contain additional +object (CRS, transformation, …) definitions. If several paths are +provided, they must be separated by the colon (:) character on Unix, and +on Windows, by the semi-colon (;) character.

+
+ +
+
+PROJ_DEBUG
+

Set the debug level of PROJ. The default debug level is zero, which results +in no debug output when using PROJ. A number from 1-3, with 3 being the most +verbose setting.

+
+ +
+
+PROJ_NETWORK
+
+

New in version 7.0.0.

+
+

If set to ON, enable the capability to use remote grids stored on CDN +(Content Delivery Network) storage, when grids are not available locally. +Alternatively, the proj_context_set_enable_network() function can +be used.

+
+ +
+
+PROJ_NETWORK_ENDPOINT
+
+

New in version 7.0.0.

+
+

Define the endpoint of the CDN storage. Normally defined through the +proj.ini configuration file locale in PROJ_LIB. +Alternatively, the proj_context_set_url_endpoint() function can +be used.

+
+ +
+
+PROJ_CURL_CA_BUNDLE
+
+

New in version 7.2.0.

+
+

Define a custom path to the CA Bundle file. This can be useful if curl +and PROJ_NETWORK are enabled. Alternatively, the +proj_curl_set_ca_bundle_path() function can be used.

+
+ +
+ + +
+