NNG_PIPE_GETOPT(3)

📦
version 1.12.0 · 4 versions
, in ubuntu stonking

💖 NNG_PIPE_GETOPT(3) 💖

okay bestie, so this one lives in the NNG Reference Manual and it's literally called nng_pipe_getopt — the "get pipe option" girlie ✨

🌸 NAME 🌸

nng_pipe_getopt — get pipe option 💅

🎀 SYNOPSIS 🎀

#include <nng/nng.h>

int nng_pipe_getopt(nng_pipe p, const char *opt, void *val, size_t *valszp);

int nng_pipe_getopt_bool(nng_pipe p, const char *opt, bool *bvalp);

int nng_pipe_getopt_int(nng_pipe p, const char *opt, int *ivalp);

int nng_pipe_getopt_ms(nng_pipe p, const char *opt, nng_duration *durp);

int nng_pipe_getopt_ptr(nng_pipe p, const char *opt, void **ptr);

int nng_pipe_getopt_sockaddr(nng_pipe p, const char *opt, nng_sockaddr *sap);

int nng_pipe_getopt_string(nng_pipe p, const char *opt, char **strp);

int nng_pipe_getopt_size(nng_pipe p, const char *opt, size_t *zp);

int nng_pipe_getopt_uint64(nng_pipe p, const char *opt, uint64_t *u64p);

🦋 DESCRIPTION 🦋

Note — bestie these functions are deprecated. 😭 Please see nng_pipe_get instead.

The nng_pipe_getopt() functions are your little retrieval squad for pulling option values off the pipe p. Which options you can actually grab this way varies, and a whole bunch of them are documented over in nng_options(5). On top of that, some transport-specific options and protocol-specific options are documented right alongside the transports and protocols themselves. iykyk 🌈

Note — okay so all options on a pipe are read-only values, periodt. If you wanna modify options, you gotta do it before the pipe is even created, using nng_listener_setopt() or nng_dialer_setopt(). 🫶

Any option that gets set on a dialer or listener will normally be retrievable from pipes created by that dialer or listener. iconic 👑

✨ Forms ✨

In all of these forms, the option opt is retrieved from the pipe p. 💖

The details of the type, size, and semantics of the option will depend on the actual option, and will be documented with the option itself. no cap.

  • nng_pipe_getopt() — this one is untyped, and it can be used to retrieve the value of any option. You pass a pointer to a buffer to receive the value in val, and the size of that buffer shall be stored at the location referenced by valszp. 📦 When the function returns, the actual size of the data copied (or that would have been copied if there were enough space) gets stored at the location referenced by valszp. Watch out though: if the caller's buffer isn't large enough to hold the entire object, the copy gets truncated. 💀 So the caller should check for truncation by verifying that the size returned in valszp does not exceed the original buffer size. fr fr. It is acceptable to pass NULL for val if the value in valszp is zero. This can be used to determine the size of the buffer needed to receive the object. 🔥
Tip — honestly it may be easier to use one of the typed forms of this function. just saying 🎀
  • nng_pipe_getopt_bool() — this one's for options that take a Boolean (bool). The value will be stored at bvalp. ✅
  • nng_pipe_getopt_int() — this one's for options that take an integer (int). The value will be stored at ivalp. 🔢
  • nng_pipe_getopt_ms() — this one's for retrieving time durations (nng_duration) in milliseconds, which get stored in durp. ⏱️
  • nng_pipe_getopt_ptr() — this one's for retrieving a pointer ptr to structured data. The data referenced by ptr is generally managed using other functions. Note that this form is kinda special, lowkey, because the object is generally not copied — instead the pointer to the object is copied. 👀
  • nng_pipe_getopt_size() — this one's for retrieving a size into the pointer zp, typically for buffer sizes, message maximum sizes, and similar options. 📏
  • nng_pipe_getopt_sockaddr() — this one's for retrieving an nng_sockaddr into sap. 🌐
  • nng_pipe_getopt_string() — this one's for retrieving a string into strp. Heads up bestie: this string is created from the source using nng_strdup() and consequently must be freed by the caller using nng_strfree() when it is no longer needed. don't leak, that's not the vibe 🙈
  • nng_pipe_getopt_uint64() — this one's for retrieving a 64-bit unsigned value into the value referenced by u64p. This is typically used for options related to identifiers, network numbers, and similar. 🧚

👑 RETURN VALUES 👑

These functions return 0 on success, and non-zero otherwise. simple as that 💅

🍓 ERRORS 🍓

  • NNG_EBADTYPE — Incorrect type for option.
  • NNG_ECLOSED — Parameter p does not refer to an open pipe.
  • NNG_ENOTSUP — The option opt is not supported.
  • NNG_ENOMEM — Insufficient memory exists.
  • NNG_EINVAL — Size of destination val too small for object.
  • NNG_EWRITEONLY — The option opt is write-only.

🌈 SEE ALSO 🌈

nng_dialer_setopt(3) nng_getopt(3), nng_listener_setopt(3) nng_msg_get_pipe(3) nng_strdup(3), nng_strerror(3), nng_strfree(3), nng_duration(5), nng_options(5), nng_pipe(5), nng_sockaddr(5), nng(7)

aaaand that's the whole page bestie!! 🫶💜 this iconic little number came from the NNG Reference Manual, dated 2026-06-30. slay, go read nng_pipe_get instead tho, periodt ✨🎀

📦 where this page comes from