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| author | Garrett D'Amore <garrett@damore.org> | 2024-03-30 23:07:20 -0700 |
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| committer | Garrett D'Amore <garrett@damore.org> | 2024-03-30 23:07:20 -0700 |
| commit | f73cd76f54b8aead38689e0ea805d5d805dfbe96 (patch) | |
| tree | 0f6643e955770a9e96a8bbd900ca957a73fe1182 /docs/reference/src/old/nng_getopt.3.adoc | |
| parent | 6f8944a96a5acd509014caae4e57dafbba51e126 (diff) | |
| download | nng-f73cd76f54b8aead38689e0ea805d5d805dfbe96.tar.gz nng-f73cd76f54b8aead38689e0ea805d5d805dfbe96.tar.bz2 nng-f73cd76f54b8aead38689e0ea805d5d805dfbe96.zip | |
Staging work. converted nng_ipc.
Diffstat (limited to 'docs/reference/src/old/nng_getopt.3.adoc')
| -rw-r--r-- | docs/reference/src/old/nng_getopt.3.adoc | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/docs/reference/src/old/nng_getopt.3.adoc b/docs/reference/src/old/nng_getopt.3.adoc new file mode 100644 index 00000000..364d8f71 --- /dev/null +++ b/docs/reference/src/old/nng_getopt.3.adoc @@ -0,0 +1,145 @@ += nng_getopt(3) +// +// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech> +// Copyright 2018 Capitar IT Group BV <info@capitar.com> +// +// This document is supplied under the terms of the MIT License, a +// copy of which should be located in the distribution where this +// file was obtained (LICENSE.txt). A copy of the license may also be +// found online at https://opensource.org/licenses/MIT. +// + +== NAME + +nng_getopt - get socket option + +== SYNOPSIS + +[source, c] +---- +#include <nng/nng.h> + +int nng_getopt(nng_socket s, const char *opt, void *val, size_t *valszp); + +int nng_getopt_bool(nng_socket s, const char *opt, bool *bvalp); + +int nng_getopt_int(nng_socket s, const char *opt, int *ivalp); + +int nng_getopt_ms(nng_socket s, const char *opt, nng_duration *durp); + +int nng_getopt_ptr(nng_socket s, const char *opt, void **ptr); + +int nng_getopt_size(nng_socket s, const char *opt, size_t *zp); + +int nng_getopt_string(nng_socket s, const char *opt, char **strp); + +int nng_getopt_uint64(nng_socket s, const char *opt, uint64_t *u64p); + +---- + +== DESCRIPTION + +IMPORTANT: These functions are deprecated. Please see xref:nng_socket_get.3.adoc[nng_socket_get]. +They may not be present if the library was built with `NNG_ELIDE_DEPRECATED`. + +(((options, socket))) +The `nng_getopt()` functions are used to retrieve option values for +the xref:nng_socket.5.adoc[socket] _s_. +The actual options that may be retrieved in this way vary. +A number of them are documented in xref:nng_options.5.adoc[nng_options(5)]. + +Additionally transport-specific options and protocol-specific options are +documented with the transports and protocols themselves. + +=== Forms + +In all of these forms, the option _opt_ is retrieved from the socket _s_. +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_getopt()`:: +This function is untyped and can be used to retrieve the value of any option. +The caller must store a pointer to a buffer to receive the value in _val_, +and the size of the 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 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_getopt_bool()`:: +This function is for options which take a Boolean (`bool`). +The value will be stored at _bvalp_. + +`nng_getopt_int()`:: +This function is for options which take an integer (`int`). +The value will be stored at _ivalp_. + +`nng_getopt_ms()`:: +This function is used to retrieve time xref:nng_duration.5.adoc[durations] +(such as timeouts), stored in _durp_ as a number of milliseconds. +(The special value ((`NNG_DURATION_INFINITE`)) means an infinite amount of time, and +the special value ((`NNG_DURATION_DEFAULT`)) means a context-specific default.) + +`nng_getopt_ptr()`:: +This function is used to retrieve a pointer, _ptr_, to structured data. +The data referenced by _ptr_ is generally managed using other functions. +Note that this form is somewhat special in that the object is generally +not copied, but instead the *pointer* to the object is copied. + +`nng_getopt_size()`:: +This function is used to retrieve a size into the pointer _zp_, +typically for buffer sizes, message maximum sizes, and similar options. + +`nng_getopt_string()`:: +This function is used to retrieve a string into _strp_. +This string is created from the source using xref:nng_strdup.3.adoc[`nng_strdup()`] +and consequently must be freed by the caller using +xref:nng_strfree.3.adoc[`nng_strfree()`] when it is no longer needed. + +`nng_getopt_uint64()`:: +This function is used to retrieve 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. + +== ERRORS + +[horizontal] +`NNG_EBADTYPE`:: Incorrect type for option. +`NNG_ECLOSED`:: Parameter _s_ does not refer to an open socket. +`NNG_EINVAL`:: Size of destination _val_ too small for object. +`NNG_ENOMEM`:: Insufficient memory exists. +`NNG_ENOTSUP`:: The option _opt_ is not supported. +`NNG_EWRITEONLY`:: The option _opt_ is write-only. + +== SEE ALSO + +[.text-left] +xref:nng_dialer_getopt.3.adoc[nng_dialer_getopt(3)], +xref:nng_listener_getopt.3.adoc[nng_listener_getopt(3)], +xref:nng_pipe_getopt.3.adoc[nng_pipe_getopt(3)], +xref:nng_setopt.3.adoc[nng_setopt(3)], +xref:nng_strdup.3.adoc[nng_strdup(3)], +xref:nng_strerror.3.adoc[nng_strerror(3)], +xref:nng_strfree.3.adoc[nng_strfree(3)], +xref:nng_duration.5.adoc[nng_duration(5)], +xref:nng_options.5.adoc[nng_options(5)], +xref:nng_socket.5.adoc[nng_socket(5)], +xref:nng.7.adoc[nng(7)] |
