nng_dialer_set(3)

# nng_dialer_set(3) Manual Page

## NAME

nng_dialer_set - set dialer option

## SYNOPSIS

    #include <nng/nng.h>

    int nng_dialer_set(nng_dialer d, const char *opt, const void *val,
        size_t valsz);

    int nng_dialer_set_bool(nng_dialer d, const char *opt, bool bval);

    int nng_dialer_set_int(nng_dialer d, const char *opt, int ival);

    int nng_dialer_set_ms(nng_dialer d, const char *opt, nng_duration dur);

    int nng_dialer_set_ptr(nng_dialer d, const char *opt, void *ptr);

    int nng_dialer_set_size(nng_dialer d, const char *opt, size_t z);

    int nng_dialer_set_string(nng_dialer d, const char *opt, const char *str);

    int nng_dialer_set_uint64(nng_dialer d, const char *opt, uint64_t u64);

## DESCRIPTION

The `nng_dialer_set()` functions are used to configure options for the dialer d. The actual options that may be configured in this way vary, and many are documented in nng_options(5).

Additionally some transport-specific options are documented with the transports themselves.

| Once a dialer has started, it is generally not possible to change its configuration.

### Forms

In all of these forms, the option opt is configured on the dialer d.

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_dialer_set()`

  This function is untyped, and can be used to configure any arbitrary data. The val pointer addresses the data to copy, and valsz is the size of the objected located at val.

| It may be easier to use one of the typed forms of this function.

`nng_dialer_set_bool()`

  This function is for options which take a Boolean (`bool`). The bval is passed to the option.

`nng_dialer_set_int()`

  This function is for options which take an integer (`int`). The ival is passed to the option.

`nng_dialer_set_ms()`

  This function is used to configure time durations (such as timeouts) using type `nng_duration`. The duration dur is an integer number of milliseconds.

`nng_dialer_set_ptr()`

  This function is used to pass a pointer, ptr, to structured data. The data referenced by ptr is generally managed by other functions. For example, TLS configuration objects created with (`nng_tls_config_alloc()`) can be passed this way.

| This form is somewhat special in that the object is generally not copied, but instead the pointer to the object is copied.

`nng_dialer_set_size()`

  This function is used to configure a size, z, typically for buffer sizes, message maximum sizes, and similar options.

`nng_dialer_set_string()`

  This function is used to pass configure a string, str. Strings passed this way must be legal UTF-8 or ASCII strings, terminated with a `NUL` (`\0`) byte. (Other constraints may apply as well, see the documentation for each option for details.)

`nng_dialer_set_uint64()`

  This function is used to configure a 64-bit unsigned value, u64. This is typically used for options related to identifiers, network numbers, and such.

## RETURN VALUES

These functions return 0 on success, and non-zero otherwise.

## ERRORS

`NNG_EBADTYPE` | Incorrect type for option.
`NNG_ECLOSED` | Parameter d does not refer to an open dialer.
`NNG_EINVAL` | The value being passed is invalid.
`NNG_ENOTSUP` | The option opt is not supported.
`NNG_EREADONLY` | The option opt is read-only.
`NNG_ESTATE` | The dialer d is already started.

## SEE ALSO

nng_dialer_create(3) nng_dialer_get(3) nng_strerror(3), nng_dialer(5), nng_duration(5), nng_options(5), nng(7)