Skip to Content
Java in a Nutshell, 5th Edition
book

Java in a Nutshell, 5th Edition

by David Flanagan
March 2005
Intermediate to advanced
1254 pages
104h 21m
English
O'Reilly Media, Inc.
Content preview from Java in a Nutshell, 5th Edition

Name

extcheck — JAR Version Conflict Utility

Synopsis

extcheck [-verbose] jarfile
               

Description

extcheck checks to see if the extension contained in the specified jarfile (or a newer version of that extension) has already been installed on the system. It does this by reading the Specification-Title and Specification-Version manifest attributes from the specified jarfile and from all of the JAR files found in the system extensions directory.

extcheck is designed for use in automated installation scripts. Without the -verbose option, it does not print the results of its check. Instead, it sets its exit code to 0 if the specified extension does not conflict with any installed extensions and can be safely installed. It sets its exit code to a nonzero value if an extension with the same name is already installed and has a specification version number equal to or greater than the version of the specified file.

Options

-verbose

Lists the installed extensions as they are checked and displays the results of the check.

See also

jar

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Java in a Nutshell, 8th Edition

Java in a Nutshell, 8th Edition

Benjamin J. Evans, Jason Clark, David Flanagan
Java in a Nutshell, 7th Edition

Java in a Nutshell, 7th Edition

Benjamin J. Evans, David Flanagan
Learning Java, 5th Edition

Learning Java, 5th Edition

Marc Loy, Patrick Niemeyer, Daniel Leuck
Learning Java, 4th Edition

Learning Java, 4th Edition

Patrick Niemeyer, Daniel Leuck

Publisher Resources

ISBN: 0596007736Supplemental ContentErrata Page