extcheck(1)						      General Commands Manual						       extcheck(1)

NAME

       extcheck - jar conflict detection utility

SYNOPSIS

       extcheck [ -verbose ] [ -Joption ] targetfile.jar

DESCRIPTION

       The extcheck utility checks a specified jar file for title and version conflicts with any extensions installed in the JDK software.  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 extcheck utility compares the Specification-title and Specification-version headers in the manifest of targetfile.jar file against  the
       corresponding  headers  in  all	Jar  files  currently  installed  in  the extension directory.	(The extension directory is jre/lib/ext by
       default.) The extcheck utility compares version numbers in the same way as the method java.lang.Package.isCompatibleWith.

       If no conflict is detected, the return code is 0.

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

OPTIONS

       The following options are supported:

       -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  option to the Java virtual machine, where option is one of the options described on the man page for the java applica-
		      tion launcher, java(1).  For example, -J-Xms48m sets the startup memory to 48 megabytes.

SEE ALSO

       jar(1)

								   13 June 2000 						       extcheck(1)