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NNG_CTX_GETOPT(3) | NNG Reference Manual | NNG_CTX_GETOPT(3) |
NAME¶
nng_ctx_getopt - get context option
SYNOPSIS¶
#include <nng/nng.h> int nng_ctx_getopt(nng_ctx ctx, const char *opt, void *val, size_t *valszp); int nng_ctx_getopt_bool(nng_ctx ctx, const char *opt, bool *bvalp); int nng_ctx_getopt_int(nng_ctx ctx, const char *opt, int *ivalp); int nng_ctx_getopt_ms(nng_ctx ctx, const char *opt, nng_duration *durp); int nng_ctx_getopt_size(nng_ctx ctx, const char *opt, size_t *zp); int nng_ctx_getopt_string(nng_ctx ctx, const char *opt, char **strp); int nng_ctx_getopt_uint64(nng_ctx ctx, const char *opt, uint64_t *u64p);
DESCRIPTION¶
Important
These functions are deprecated. Please see nng_ctx_get.
They may not be present if the library was built with
NNG_ELIDE_DEPRECATED.
The nng_ctx_getopt() functions are used to retrieve option values for the context ctx. The actual options that may be retrieved in this way vary. A number of them are documented in nng_options(5).
Note
Context options are protocol specific.
The details will be documented with the protocol.
Forms¶
In all of these forms, the option opt is retrieved from the context ctx. The forms vary based on the type of the option they take.
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.
nng_ctx_getopt()
When the function returns, the actual size of the data copied (or that would have been copied if sufficient space were present) is stored at the location referenced by valszp. If the caller’s buffer is not large enough to hold the entire object, then the copy is truncated. Therefore the caller should check for truncation by verifying that the returned size in valszp does not exceed the original buffer size.
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
It may be easier to use one of the typed forms of this function.
nng_ctx_getopt_bool()
nng_ctx_getopt_int()
nng_ctx_getopt_ms()
nng_ctx_getopt_size()
nng_ctx_getopt_string()
nng_ctx_getopt_uint64()
RETURN VALUES¶
These functions return 0 on success, and non-zero otherwise.
ERRORS¶
NNG_EBADTYPE
NNG_ECLOSED
NNG_EINVAL
NNG_ENOMEM
NNG_ENOTSUP
NNG_EWRITEONLY
SEE ALSO¶
nng_ctx_setopt(3), nng_strdup(3), nng_strerror(3), nng_strfree(3), nng_duration(5), nng_ctx(5), nng_options(5), nng(7)
2024-10-11 |