---
name: "displaydrivers"
section: "1grass"
platform: "linux"
package: "grass-doc"
version: "8.4.1-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/displaydrivers"
---

# displaydrivers(1grass)

## Display drivers

The current command line rendering mechanism is direct rendering into a file. The driver is selected by setting the `GRASS_RENDER_IMMEDIATE` variable or by running *d.mon* module.

**List of available display drivers:**

- •

  Cairo driver

- •

  PNG driver

- •

  PS driver (Postscript)

- •

  HTMLMAP driver

## NOTES

### GRASS\_RENDER\_COMMAND

If environmental variable GRASS\_RENDER\_COMMAND is defined, rendering is redirected by display library to the given external command defined by this variable. Currently only Python scrips are supported.

Lets start with simple example of Python script called *render.py*:\

```
#!/usr/bin/env python3
import os
import sys
import grass.script as gs
from grass.script import task as gtask
os.environ[’GRASS_RENDER_IMMEDIATE’] = ’default’
os.environ[’GRASS_RENDER_FILE’] = ’output.png’
cmd, dcmd = gtask.cmdstring_to_tuple(sys.argv[1])
gs.run_command(’d.text’, text="Test of GRASS_RENDER_COMMAND redirection")
os.environ[’GRASS_RENDER_FILE_READ’] = ’TRUE’
gs.run_command(cmd, **dcmd)
```

After defining GRASS\_RENDER\_COMMAND variable (example for Bash):\

```
export GRASS_RENDER_COMMAND=render.py
```

Display GRASS modules like *d.rast* or *d.vect* will be executed by *render.py* program. For example the command\

```
d.vect roadsmajor
```

produces output PNG file *output.png* which will contain rendered features from vector map *roadsmajor* and sample text *"Test of* *GRASS\_RENDER\_COMMAND redirection"*.

## SEE ALSO

*d.mon,* *variables*

## SOURCE CODE

Available at: Display drivers source code (history)

Accessed: Monday Feb 24 10:57:24 2025

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