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

# g.message(1grass)

Prints a message, warning, progress info, or fatal error in the GRASS way. This module should be used in scripts for messages served to user.

## NAME

**g.message**  - Prints a message, warning, progress info, or fatal error in the GRASS way.\
 This module should be used in scripts for messages served to user.

## KEYWORDS

general, support, scripts

## SYNOPSIS

**g.message**\
 **g.message --help**\
 **g.message** \[-**wedpiv**\] **message**=*string*  \[**debug**=*integer*\]   \[--**help**\]  \[--**verbose**\]  \[--**quiet**\]  \[--**ui**\]

### Flags:

- **-w**

  Print message as warning

- **-e**

  Print message as fatal error

- **-d**

  Print message as debug message

- **-p**

  Print message as progress info

- **-i**

  Print message in all modes except of quiet mode\
   Message is printed on GRASS\_VERBOSE\>=1

- **-v**

  Print message only in verbose mode\
   Message is printed only on GRASS\_VERBOSE\>=3

- **--help**

  Print usage summary

- **--verbose**

  Verbose module output

- **--quiet**

  Quiet module output

- **--ui**

  Force launching GUI dialog

### Parameters:

- **message**=*string* **\[required\]**

  Text of the message to be printed\
   Message is printed on GRASS\_VERBOSE\>=2

- **debug**=*integer*

  Level to use for debug messages\
   Options: *0-5*\
   Default: *1*

## DESCRIPTION

*g.message* prints a message, warning, progress info, or fatal error in the GRASS GIS way. This program is to be used in Shell/Perl/Python scripts, so the author does not need to use the `echo` program. The advantage of *g.message* is that it formats messages just like other GRASS modules do and that its functionality is influenced by the `GRASS_VERBOSE` and `GRASS_MESSAGE_FORMAT` environment variables.

The program can be used for standard informative messages as well as warnings (**-w** flag) and fatal errors (**-e** flag). For debugging purposes, the **-d** flag will cause *g.message* to print a debugging message at the given level.

## NOTES

Messages containing "`=`" must use the full **message=** syntax so the parser doesn’t get confused.

If you want a long message (multi-line) to be dealt with as a single paragraph, use a single call to *g.message* with text split in the script using the backslash as the last character. (In shell scripts don’t close the "quote")

A blank line may be obtained with\

```
g.message message=""
```

Redundant whitespace will be stripped away.

It’s advisable to single quote the messages that are to be printed literally. It prevents a number of characters (most notably, space and the dollar sign ’`$`’) from being treated specifically by the shell.

When it is necessary to include, for example, a variable’s value as part of the message, the double quotes may be used, which do not deprive the dollar sign of its special variable-expansion powers.

While it is known that the interactive Bash instances may treat the exclamation mark ’`!`’ character specifically (making single quoting of it necessary), it shouldn’t be the case for the non-interactive instances of Bash. Nonetheless, to avoid context-based confusion later on you are encouraged to single-quote messages that do not require `$VARIABLE` expansion.

### Usage in Python scripts

GRASS Python Scripting Library defines special wrappers for *g.message*.

- •

  `debug()` for `g.message -d`

- •

  `error()` for `g.message -e`

- •

  `fatal()` for `g.message -e` + `exit()`

- •

  `info()` for `g.message -i`

- •

  `message()` for `g.message`

- •

  `verbose()` for `g.message -v`

- •

  `warning()` for `g.message -w`

Note: The Python tab in the *wxGUI* can be used for entering the following sample code:

```
import grass.script as gcore
gcore.warning("This is a warning")
```

is identical with\

```
g.message -w message="This is a warning"
```

### VERBOSITY LEVELS

Controlled by the "`GRASS_VERBOSE`" environment variable. Typically this is set using the **--quiet** or **--verbose** command line options.

- •

  0 - only errors and warnings are printed

- •

  1 - progress messages are printed

- •

  2 - all module messages are printed

- •

  3 - additional verbose messages are printed

### DEBUG LEVELS

Controlled by the "`DEBUG`" GRASS *gisenv* variable (set with *g.gisenv*).\
 Recommended levels:

- •

  1 - message is printed once or few times per module

- •

  3 - each row (raster) or line (vector)

- •

  5 - each cell (raster) or point (vector)

## EXAMPLES

This basic example prints the message "hello" in the console:\

```
g.message message="hello"
```

To print a message as an error message use the **-e** flag:\

```
g.message -e message="my error"
```

To print a message highlighted as a debug message ("D0/0: debug") in the console, use the **-d** flag. Optionally the debug level can be defined (see also g.gisenv for details):\

```
# Levels: (recommended levels)
#   0 - silence
#   1 - message is printed once or few times per module
#   3 - each row (raster) or line (vector)
#   5 - each cell (raster) or point (vector)
g.message -d message="debug" debug=0
```

To print a message highlighted as a warning message ("WARNING: my warning") in the console, use the **-w** flag:\

```
g.message -w message="my warning"
```

## SEE ALSO

*GRASS variables and environment variables*\
 *g.gisenv,* *g.parser*

## AUTHOR

Jachym Cepicky

## SOURCE CODE

Available at: g.message source code (history)

Accessed: Monday Feb 24 17:50:29 2025

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