JATTACH(1)

📦
version 2.2 · 2 versions
, in debian trixie, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

💖 JATTACH(1) 💖

okay bestie, gather round, because jattach from the General Commands Manual (section 1, we love a classic) is genuinely one of the most underrated little tools and i need you to be obsessed with it the way i am 🫶

✨ NAME ✨

jattach — it's a dynamic attach utility for the jvm, no cap. tiny program, huge main character energy 👑

🌸 SYNOPSIS 🌸

jattach pid
[load|properties|agentProperties|datadump|threaddump|dumpheap|inspectheap|setflag|printflag|jcmd]
[args]

so like. you give it a pid. then you give it one of those commands up there. then maybe some args if the command is the type to need them. that's the whole vibe check. literally it 💅

🦋 DESCRIPTION 🦋

okay so picture this: jattach is an all in one jmap, jstack, jcmd, jinfo implementation — all of that, crammed into one tiny single C program. i know. i KNOW. the way that it does the job of four separate tools and still fits in your pocket?? iconic. no bloat, no drama, just vibes and syscalls 🎀

💅 OPTIONS 💅

here's the menu bestie, one bullet per command, do not skip any of them, they're all serving 🍓

  • load — load an agent library. yeah. you're loading an agent. into the JVM. very sneaky, very powerful, very slay 🔥
  • properties — print the system properties. all of them. the whole tea ☕
  • agentProperties — print the agent properties. (yes it's a different set from properties, don't get it twisted 🙈)
  • datadump — show a heap and thread summary. like a lil trailer for what's going on in there 🎬
  • threaddump — dump all the stack traces (like jstack does). every thread, every frame, exposed 💀
  • dumpheap — mydumpfile.hprof dump heap (like jmap -dump:live,format=b). note that mydumpfile.hprof up there is your filename, bestie, that's the args slot — swap in whatever you want, just keep the .hprof energy 🧚
  • inspectheap — create a heap histogram (like jmap -histo). little bar chart of who's eating all your memory. the receipts. the audacity of some objects 📊
  • setflag — modify a manageable JVM flag. careful with this one, you're changing things live 🫣
  • printflag — print a JVM flag. just read it. no touching. safe. chill. 🧘
  • jcmd — execute a jcmd command. the escape hatch. the wildcard. the "i know what i'm doing" option 🌈
ngl bestie, that's literally the whole page. nine commands, one pid, zero fuss. the way it just works 😭💜

mwah, that's a wrap 🎀 this was JATTACH(1) from the General Commands Manual, dated January 16 2024 — go forth and attach, bestie, you got this ✨👑

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