JMAP(1)

💅 jmap(1) — print details of a specified process

okay bestie, welcome to jmap from the JDK Commands manual — page JMAP(1), main character of this terminal moment. She prints details of a specified process. Periodt. 💖

🌸 NAME

jmap — print details of a specified process. That's the whole NAME section, no cap. ✨

✨ 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 (the section below, iykyk). 🫶
• 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. It's giving "I have the tea on your process" and honestly? Obsessed. Lowkey iconic, highkey useful, fr fr. 💖

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

k bye bestie 💖 — source/version is JDK 21, date is 2023, and that's the cute JMAP(1) sign-off. Mwah. 🫶