Ubuntu Manpage: nng_pipe_getopt

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
           These functions are deprecated. Please see nng_pipe_get.

       The nng_pipe_getopt() functions are used to retrieve option values for the pipe p. The
       actual options that may be retrieved in this way vary, and many are documented in
       nng_options(5). Additionally some transport-specific options and protocol-specific options
       are documented with the transports and protocols themselves.

           Note
           All options on a pipe are read-only values. Modification of options may be done before
           the pipe is created using nng_listener_setopt() or nng_dialer_setopt().

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

   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.

       nng_pipe_getopt()
           This is untyped, and can be used to retrieve the value of any option. 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 size returned 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_pipe_getopt_bool()
           This function is for options which take a Boolean (bool). The value will be stored at
           bvalp.

       nng_pipe_getopt_int()
           This function is for options which take an integer (int). The value will be stored at
           ivalp.

       nng_pipe_getopt_ms()
           This function is used to retrieve time durations (nng_duration) in milliseconds, which
           are stored in durp.

       nng_pipe_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_pipe_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_pipe_getopt_sockaddr()
           This function is used to retrieve an nng_sockaddr into sap.

       nng_pipe_getopt_string()
           This function is used to retrieve a string into strp. 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.

       nng_pipe_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

       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.

NAME

SYNOPSIS

DESCRIPTION

RETURN VALUES

ERRORS

SEE ALSO