---
name: "nescc-ncg"
section: "1"
platform: "linux"
package: "nescc"
version: "1.3.5-1.1"
release: "Debian 12 (Bookworm)"
platforms: ["linux"]
url: "https://new.carta.tech/nescc-ncg"
---

# nescc-ncg(1)

extract constants from nesC files

## NAME

nescc-ncg - extract constants from nesC files

## SYNOPSIS

**nescc-ncg** \[any nescc option\] \[tool-specific options\]\
           \[**-o** *output-file*\] \[**-nescc=***driver*\]\
           *tool* *nesC-file* *filenames-or-constant-names...*

## DESCRIPTION

**nescc-ncg** is a tool to extract constants from nesC files for use with other applications. It is typically used in conjunction with **nescc-mig** (which generates code to process nesC messages) to extract constants that are used in particular messages (e.g., constants representing various commands).

The *tool* argument specifies what tool should be generated, the *nesC-file* specifies a nesC file which uses the constants you want to extract.  If your constants are all in a single .h file that does not depend on any other files, then you can specify the .h file directly as the *msg-format-file*. Note that if some of your constants are defined with **unique(...)** or **uniqueCount(...)**, you must specify your whole application as the *nesC-file*, or you will not get the  correct constant values.

Each *filenames-or-constant-names* is either a constant name (if it consists only of letters, numbers and \_) or a filename. In the former case, the specified constant will be extracted, in the latter case all constants from the specified C file will be extracted. Only constants declared in C files will be found by **nescc-ncg**.

The current tools are **java**, **python** and **C**, which generate java, python and C code that contains the values of the  requested constants.

## OPTIONS

You can pass any **nescc** option, as well as

- **-o** *output-file*

  Specify the file in which to output the generated code.

- **-nescc=***driver*

  Use *driver* instead of **nescc** to extract constants. For example, if you specify **-nescc=ncc**, you can use **nescc-ncg** to extract constants from TinyOS applications (which are normally compiled with **ncc**).

- tool-specific options

  See below.

## JAVA TOOL

This tool generates a java class with the values of the requested constants. These constants will be **public final static** and have a type chosen from **byte, short, char, int, long** (the chosen type will be the  first one in this list that can hold the constants value - this reduces the need for casts).

The java tool accepts the following options:

- **-java-classname=***full-class-name*

  This option is required and specifies the package and name of the generated class. If the *full-class-name* has no '.', then no package directive is included in the output.

- **-java-extends=***class-name*

  Specify the class the generated class will extend. The default is **Object**.

## PYTHON TOOL

This tool generates a Python class with the values of the requested constants. These constants will be class (rather than instance) variables.

The Python tool accepts the following options:

- **-python-classname=***full-class-name*

  This option is required and specifies the name of the generated class.

- **-python-extends=***class-name*

  Specify the class the generated class will extend. The default is is to not inherit.

## C TOOL

This tool generates a C header file with the values of the requested constants (defined as **enum** constants).

The C tool accepts the following option:

- **-c-prefix=***prefix*

  This option specifies a *prefix* to attach to the generated constants.

## ERRORS

**nescc-ncg** reports an error if ncc cannot compile *nesC-file*.

## SEE ALSO

[*nescc*(1)](/nescc/1.md), [*nescc-mig*(1)](/nescc-mig/1.md)