jmap [option] <executable <core> - what does that mean and how to use it?

Question

I'm trying to use jmap utility. It's too hard to specify pid each time, so I search for easier option. In jmap's help I found an option

jmap [option] < executable < core >

But this absolutely not self-explanatory. What stands for executable/core? How can I specify it ? Haven't found any sample.

Answer 1

From the documentation:

executable

Java executable from which the core dump was produced.

core

core file for which the memory map is to be printed.

I agree, that is a bit terse...

The core is the core dump to get the heap from, and the executable is the Java executable the app that produced the core dump was run with

And this question provides an example of using it:

jmap -dump:format=b,file=dump.hprof /usr/java/jdk1.6.0_16/bin/java core.dump.2878