extcheck(1)                                           extcheck(1)



NAME
       extcheck - jar conflict detection utility

SYNOPSIS
       extcheck [ -verbose ] [ -J ] targetfile.jar

DESCRIPTION
       The extcheck utility checks a specified jar file for title
       and version conflicts with any extensions installed in the
       JDK(tm) software.  Before installing an extension, you can
       use this utility to see if the same or a more recent  ver-
       sion of the extension is already installed.

       The  extcheck utility compares the Specification-title and
       Specification-version headers in the manifest  of  target-
       file.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.

OPTIONS
       The following options are supported:

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

       -J  option     Pass  option  to  the Java virtual machine,
                      where  option  is  one   of   the   options
                      described  on  the  man  page  for the java
                      application launcher, java(1). For example,
                      -J-Xms48m  sets  the  startup  memory to 48
                      megabytes. It is a common convention for -J
                      to  pass  options to the underlying virtual
                      machine.

EXIT STATUS
       The following exit values are returned:

       0              No conflict is detected.

       non-zero       If the manifest of any of the jar files  in
                      the extensions directory has the same Spec-
                      ification-title and the  same  or  a  newer
                      Specification-version number, or if target-
                      file.jar does not have  the  Specification-
                      title  or  Specification-version attributes
                      in its manifest.

SEE ALSO
       jar(1)



                           14 July 2000               extcheck(1)