NNG_CTX_OPEN(3)

💖 NNG_CTX_OPEN(3) — the nng manual, but make it cute 💖

okay bestie, pull up a chair, we're talking about nng_ctx_open — this one lives in the NNG Reference Manual and it's genuinely one of my faves, no cap. it's giving "let me spin you up a whole new context on an existing socket" and honestly? iconic. 🦋

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✨ NAME ✨

nng_ctx_open — create context 💅

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🌸 SYNOPSIS 🌸

#include <nng/nng.h>

int nng_ctx_open(nng_ctx *ctxp, nng_socket s);

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💜 DESCRIPTION 💜

so here's the tea: nng_ctx_open() creates a separate context to be used with the socket s, and it returns that little baby at the location pointed to by ctxp. that's it, that's the whole vibe. 🎀

Note — not every protocol supports creation of separate contexts, bestie. do not come for me when it doesn't. it's not me, it's the protocol. 😭

contexts let you use stateful operations independently and concurrently on the same socket. like, think about it: two different contexts created on a rep socket can each receive their own requests and send their own replies back, without any regard to — or interference with — each other. two main characters, one socket. zero drama. 👑

TIP: using contexts is an excellent way to write simpler concurrent applications, while still retaining the benefits of the protocol-specific advanced processing — and it avoids the need to bypass all of that with raw mode sockets. so you get the cute high-level stuff AND the concurrency. slay.

Note — use of contexts with raw mode sockets is nonsensical and not supported. fr fr. don't do it. 🙈

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🫶 RETURN VALUES 🫶

this function returns 0 on success, and non-zero otherwise. that's the whole thing. periodt.

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🔥 ERRORS 🔥

• NNG_ENOMEM — insufficient memory is available. your machine said "no thoughts, head empty". 💀
• NNG_ENOTSUP — the protocol does not support separate contexts, or the socket was opened in raw mode. either way: not supported, babe. 🙅‍♀️

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🌈 SEE ALSO 🌈

nng_ctx_close(3), nng_ctx_getopt(3), nng_ctx_recv(3), nng_ctx_send(3), nng_ctx_setopt(3), nng_strerror(3), nng_ctx(5), nng_socket(5), nng_rep(7), nng_req(7), nng(7)

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and that's the whole page, bestie!! 💖 this one's from the NNG Reference Manual, dated 2026-06-30, and it says NNG_CTX_OPEN(3) at the bottom too — so yeah, that's the source, the version, and the date all wrapped up with a bow. 🎀 go forth and open some contexts, you've got this. mwah. 💅✨