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