JALV(1)

🌸 NAME 🌸

jalv — run an LV2 plugin with a command-line interface 💅 (yes, that's it, that's the whole vibe)

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✨ SYNOPSIS ✨

jalv [-dhipstx] [-b size] [-c symbol=value] [-U ui_uri] [-l dir]
     [-n name] plugin_state

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🦋 DESCRIPTION 🦋

okay so bestie, jalv is a simple LV2 host that runs one plugin. literally one. It exists in several versions, and the one you're reading about right now is the one with an interactive command-line interface — so you get a little prompt and you get to type at it, iconic behavior fr fr 🎀

jalv has exactly one positional argument, and it can be a plugin URI, a preset URI, or the path to a bundle or data file that describes one. That's it. No cap, it's giving "just tell me where the plugin is and I'll handle the rest" ✨

The options are as follows:

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👑 OPTIONS 👑

• -b bytes — Buffer size for communication between plugin and UI. The default value should be enough, but if there are overflows, you can use this option to allocate more space. (translation: buffering issues? throw more bytes at it 🫶)
• -c symbol=value — Set control value, for example -c vol=1.4 where “vol” is the symbol of a control port on the plugin. very "set it and forget it" 💅
• -d — Dump communication between plugin and UI to stdout. ⚠️ heads up bestie ⚠️ this may print an extreme amount of text, so piping the output to a pager or a file is recommended. like, do not just let it scream into your terminal, okay? 😭
• -h — Print the command line options and exit. (the classic cry for help helper 🌸)
• -i — Ignore input on stdin and run non-interactively. no chatty little prompt, just vibes ✨
• -l frames — Length of an audio block.
• -n name — Use the given JACK client name. Note that JACK may adjust the name if necessary unless -x is also given. (JACK is gonna do its own thing unless you tell it not to 💀)
• -p — Print control output changes to stdout. lowkey perfect for watching your values move 🔥
• -s — Show plugin UI if possible. This option only works when plugins provide a UI that uses the non-embeddable showHide interface. For embeddable UIs, use jalv.gtk3(1) instead. iykyk 🧚
• -t — Print debug trace messages. This enables the “trace” LV2 log, which is used by some plugins to print debugging output. Some extra internal error messages are also enabled. Note that this may print in the audio thread, which can cause dropouts. so like… great for debugging, not great for your glitch-free listening experience 🙈
• -U uri — Load the UI with the given URI. Usually only one suitable UI is available on a given platform, which is used by default. If there are several, this option can be used to select which is loaded. main character energy: picking your UI yourself 👑
• -V — Print version information and exit. ⭐
• -x — Use only the exact JACK client name given by -n, or exit if it's unavailable. no compromises, no substitutions, periodt 💅

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🌈 COMMANDS 🌈

The Jalv prompt supports several commands for interactive control — here's the whole squad 🫶

• help — Display help message.
• controls — Print settable control values.
• monitors — Print output control values.
• presets — Print available presets.
• preset uri — Load and apply preset.
• quit — Quit program. (the goodbye button 🎀)
• set index value — Set control value by port index (a non-negative integer).
• set symbol value — Set control value by symbol (a simple string identifier).

okay tiny ✨lore drop✨ about that preset line: in the source it renders as Ic preset Ar path Load and apply preset. — a little troff artifact that snuck through, and we're keeping it real with you, so here it is, unedited 💀

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🧚 ENVIRONMENT 🧚

• LV2_PATH — Search path for LV2 bundles, in PATH format. (yes bestie, same shape as your regular PATH, you already know the drill 🌸)

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💜 SEE ALSO 💜

• jalv.gtk3(1)
• jalv.qt5(1)
• lv2ls(1)

go read those too, they're all part of the same little family 🦋

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🎀 AUTHORS 🎀

jalv was written by David Robillard ⟨d@drobilla.net⟩, with contributions by Robin Gareus, Hanspeter Portner, and others. legends, every single one of them 👑

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and that's the whole page, bestie!! 💖 this cutie little manual came to you from Debian, dated August 1, 2025 — take a screenshot, tell your friends, run your plugins, slay ✨🌸💅