Release resource file


The release resource file specifies which applications 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 is to 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()

Release name.

Vsn = string()

Release version.

EVsn = string()

ERTS version the release is intended for.

Application = atom()

Name of an application included in the release.

AppVsn = string()

Version of an application included in the release.

Type = permanent | transient | temporary | load | none

Start type of an application included in the release.

If Type = permanent | transient | temporary, the application is loaded and started in the corresponding way, see application(3).

If Type = load, the application is only loaded.

If Type = none, the application is not loaded and not started, although the code for its modules is loaded.

Defaults to permanent

IncApps = [atom()]

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 ( and overrides this value. Defaults to the same value as in the application resource file.


The list of applications must contain the Kernel and STDLIB applications.

See Also