# rel

### FILE

rel

### FILE SUMMARY

Release resource file

### DESCRIPTION

The release resource file specifies which applications are are included in a release (system) based on Erlang/OTP.

This file is used by the functions in `systools` when generating start scripts (`.script`, `.boot`) and release upgrade files (`relup`).

### FILE SYNTAX

The release resource file should be called `Name.rel`.

The `.rel` file contains one single Erlang term, which is called a release specification. The file has the following syntax:

    {release, {RelName,Vsn}, {erts, EVsn},
      [{Application, AppVsn} |
       {Application, AppVsn, Type} |
       {Application, AppVsn, IncApps} |
       {Application, AppVsn, Type, IncApps}]}.

- `RelName = string()` is the name of the release.
- `Vsn = string()` is the version of the release.
- `EVsn = string()` is the version of ERTS the release is intended for.
- `Application = atom()` is the name of an application included in the release.
- `AppVsn = string()` is the version of an application included in the release.
- `Type = permanent | transient | temporary | load | none` is the start type of an application included in the release.
  If `Type = permanent | transient | temporary`, the application will be loaded and started in the corresponding way, see `application(3)`. If `Type = load`, the application will only be loaded. If `Type = none`, the application will be neither loaded nor started, although the code for its modules will be loaded. Defaults to `permanent`
- `IncApps = [atom()]` is a list of applications that are included by an application included in the release.
  The list must be a subset of the included applications specified in the application resource file (`Application.app`) and overrides this value. Defaults to the empty list.

| The list of applications must contain the `kernel` and `stdlib` applications.

### SEE ALSO

application(3), relup(4), systools(3)

### AUTHORS

Gunilla Hugosson - support@erlang.ericsson.se

sasl 2.1.5.1
Copyright © 1991-2007 Ericsson AB