---

Copyright (c) 2004, 2024, Oracle and/or its affiliates. All rights reserved.

DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

This code is free software; you can redistribute it and/or modify it

under the terms of the GNU General Public License version 2 only, as

published by the Free Software Foundation.

This code is distributed in the hope that it will be useful, but WITHOUT

ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License

version 2 for more details (a copy is included in the LICENSE file that

accompanied this code).

You should have received a copy of the GNU General Public License version

2 along with this work; if not, write to the Free Software Foundation,

Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

or visit www.oracle.com if you need additional information or have any

questions.

title: ‘JMAP(1) JDK @@VERSION_SHORT@@ | JDK Commands’ date: @@COPYRIGHT_YEAR@@ lang: en

Name

jmap - print details of a specified process

Synopsis

Note: This command is experimental and unsupported.

jmap [options] pid

options : This represents the jmap command-line options. See [Options for the jmap Command].

pid : The process ID for which the information specified by the options is to be printed. The process must be a Java process. To get a list of Java processes running on a machine, use either the ps command or, if the JVM processes are not running in a separate docker instance, the jps command.

Description

The jmap command prints details of a specified running process.

Note:

This command is unsupported and might not be available in future releases of the JDK. On Windows Systems where the dbgeng.dll file isn‘t present, the Debugging Tools for Windows must be installed to make these tools work. The PATH environment variable should contain the location of the jvm.dll file that’s used by the target process or the location from which the core dump file was produced.

Options for the jmap Command

-clstats pid : Connects to a running process and prints class loader statistics of Java heap.

-finalizerinfo pid : Connects to a running process and prints information on objects awaiting finalization.

-histo[:live] pid : Connects to a running process and prints a histogram of the Java object heap. If the live suboption is specified, it then counts only live objects.

-dump:dump_options pid : Connects to a running process and dumps the Java heap. The dump_options include:

-   `live` --- When specified, dumps only the live objects; if not
    specified, then dumps all objects in the heap.

-   `format=b` --- Dumps the Java heap in `hprof` binary format

-   `file=`*filename* --- Dumps the heap to *filename*

Example: `jmap -dump:live,format=b,file=heap.bin` *pid*