add_uevent_var(9)

✨ add_uevent_var ✨

okay so bestie, we're in the Kernel API Manual (section 9, the kernel-functions era 🫶) and today's main character is add_uevent_var — she literally just adds a key=value string into the environment buffer 💅

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🌸 NAME 🌸

add_uevent_var — add key value string to the environment buffer ✨

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🎀 SYNOPSIS 🎀

int add_uevent_var (struct kobj_uevent_env *env , const char *format ,
... );

like, that's the whole vibe. three-ish things in, one int out. periodt. 💖

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🦋 ARGUMENTS 🦋

• env — the environment buffer structure, aka the little container she's gonna scoot the string into 🧺
• format — the printf format for the key=value pair, so yes she takes format strings like the icon she is 🎀
• ... — the variable arguments, aka whatever the format is hungry for 🍓

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💜 DESCRIPTION 💜

okay so the whole deal, no cap: she returns 0 if the environment variable was added successfully, or -ENOMEM if no space was available 😭 that's it, that's the entire personality. lowkey iconic for how hard she works for such a short description.

ngl bestie, if you see -ENOMEM come back, that's the "no space was available" situation — not a you problem, just a full-buffer problem 🙈

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🌈 SEE ALSO 🌈

• Kernel file ./lib/kobject_uevent.c
• kobject_synth_uevent(9)
• kobject_uevent_env(9)
• kobject_uevent(9)

like the whole uevent friend group, fr fr — go say hi to all of them 👑

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and that's the page!! mwah 💋 this one came from ./lib and it's dated October 2026, and yes the header and footer both say add_uevent_var(9) because consistency is also iconic ✨🦋💅