## Name

extcheck - A utility to detect jar conflicts

f3extcheck detects version conflicts between a target jar file and currently installed extension jar files.

## SYNOPSIS

    f3
    extcheck [ -verbose ] targetfile.jar

## DESCRIPTION

The f3extcheck utility checks a specified Jar file for title and version conflicts with any extensions installed in the Java(TM) SDK. Before installing an extension, you can use this utility to see if the same or a more recent version of the extension is already installed.

The f3extcheck utility compares the f2Specification-title and f2Specification-version headers in the manifest of the f2targetfile.jar file against the corresponding headers in all Jar files currently installed in the extension directory. (The extension directory is f2jre/lib/ext by default.) The f3extcheck utility compares version numbers in the same way as the method f2java.lang.Package.isCompatibleWith.

If no conflict is detected, the return code is f20.

If the manifest of any jar file in the extensions directory has the same f2Specification-title and the same or a newer f2Specification-version number, a non-zero error code is returned. A non-zero error code is also returned if f2targetfile.jar does not have the f2Specification-title or f2Specification-version attributes in its manifest.

## OPTIONS

-verbose Lists Jar files in the extension directory as they are checked. Additionally, manifest attributes of the target jar file and any conflicting jar files are also reported.

-Joption Pass f2option to the Java virtual machine, where f2option is one of the options described on the reference page for the java(1). For example, f3-J-Xms48m sets the startup memory to 48 megabytes.

## SEE ALSO

jar(1)