Context

Data Structures
struct	iio_context
	Contains the representation of an IIO context. More...

Functions
__api struct iio_context *	iio_create_default_context (void)
	Create a context from local or remote IIO devices. More...
__api struct iio_context *	iio_create_local_context (void)
	Create a context from local IIO devices (Linux only) More...
__api struct iio_context *	iio_create_xml_context (const char *xml_file)
	Create a context from a XML file. More...
__api struct iio_context *	iio_create_xml_context_mem (const char *xml, size_t len)
	Create a context from XML data in memory. More...
__api struct iio_context *	iio_create_network_context (const char *host)
	Create a context from the network. More...
__api struct iio_context *	iio_create_context_from_uri (const char *uri)
	Create a context from a URI description. More...
__api struct iio_context *	iio_context_clone (const struct iio_context *ctx)
	Duplicate a pre-existing IIO context. More...
__api void	iio_context_destroy (struct iio_context *ctx)
	Destroy the given context. More...
__api int	iio_context_get_version (const struct iio_context *ctx, unsigned int *major, unsigned int *minor, char git_tag[8])
	Get the version of the backend in use. More...
__api __pure const char *	iio_context_get_xml (const struct iio_context *ctx)
	Obtain a XML representation of the given context. More...
__api __pure const char *	iio_context_get_name (const struct iio_context *ctx)
	Get the name of the given context. More...
__api __pure const char *	iio_context_get_description (const struct iio_context *ctx)
	Get a description of the given context. More...
__api __pure unsigned int	iio_context_get_attrs_count (const struct iio_context *ctx)
	Get the number of context-specific attributes. More...
__api int	iio_context_get_attr (const struct iio_context *ctx, unsigned int index, const char **name, const char **value)
	Retrieve the name and value of a context-specific attribute. More...
__api const char *	iio_context_get_attr_value (const struct iio_context *ctx, const char *name)
	Retrieve the value of a context-specific attribute. More...
__api __pure unsigned int	iio_context_get_devices_count (const struct iio_context *ctx)
	Enumerate the devices found in the given context. More...
__api __pure struct iio_device *	iio_context_get_device (const struct iio_context *ctx, unsigned int index)
	Get the device present at the given index. More...
__api __pure struct iio_device *	iio_context_find_device (const struct iio_context *ctx, const char *name)
	Try to find a device structure by its name of ID. More...
__api int	iio_context_set_timeout (struct iio_context *ctx, unsigned int timeout_ms)
	Set a timeout for I/O operations. More...

Detailed Description

Function Documentation

iio_context_clone()

__api struct iio_context* iio_context_clone

(

const struct iio_context *

ctx

)

Duplicate a pre-existing IIO context.

Parameters

ctx	A pointer to an iio_context structure

Returns

On success, A pointer to an iio_context structure

On failure, NULL is returned and errno is set appropriately

iio_context_destroy()

__api void iio_context_destroy

(

struct iio_context *

ctx

)

Destroy the given context.

Parameters

ctx	A pointer to an iio_context structure

NOTE: After that function, the iio_context pointer shall be invalid.

iio_context_find_device()

__api __pure struct iio_device* iio_context_find_device	(	const struct iio_context *	ctx,
		const char *	name
	)

Try to find a device structure by its name of ID.

Parameters

ctx	A pointer to an iio_context structure
name	A NULL-terminated string corresponding to the name or the ID of the device to search for

Returns

On success, a pointer to an iio_device structure

If the name or ID does not correspond to any known device, NULL is returned

iio_context_get_attr()

__api int iio_context_get_attr	(	const struct iio_context *	ctx,
		unsigned int	index,
		const char **	name,
		const char **	value
	)

Retrieve the name and value of a context-specific attribute.

Parameters

ctx	A pointer to an iio_context structure
index	The index corresponding to the attribute
name	A pointer to a const char * pointer (NULL accepted)
value	A pointer to a const char * pointer (NULL accepted)

Returns

On success, 0 is returned

On error, a negative errno code is returned

Introduced in version 0.9.

iio_context_get_attr_value()

__api const char* iio_context_get_attr_value	(	const struct iio_context *	ctx,
		const char *	name
	)

Retrieve the value of a context-specific attribute.

Parameters

ctx	A pointer to an iio_context structure
name	The name of the context attribute to read

Returns

On success, a pointer to a static NULL-terminated string

If the name does not correspond to any attribute, NULL is returned

Introduced in version 0.9.

iio_context_get_attrs_count()

__api __pure unsigned int iio_context_get_attrs_count

(

const struct iio_context *

ctx

)

Get the number of context-specific attributes.

Parameters

ctx	A pointer to an iio_context structure

Returns

The number of context-specific attributes

Introduced in version 0.9.

iio_context_get_description()

__api __pure const char* iio_context_get_description

(

const struct iio_context *

ctx

)

Get a description of the given context.

Parameters

ctx	A pointer to an iio_context structure

Returns

A pointer to a static NULL-terminated string

NOTE:The returned string will contain human-readable information about the current context.

iio_context_get_device()

__api __pure struct iio_device* iio_context_get_device	(	const struct iio_context *	ctx,
		unsigned int	index
	)

Get the device present at the given index.

Parameters

ctx	A pointer to an iio_context structure
index	The index corresponding to the device

Returns

On success, a pointer to an iio_device structure

If the index is invalid, NULL is returned

iio_context_get_devices_count()

__api __pure unsigned int iio_context_get_devices_count

(

const struct iio_context *

ctx

)

Enumerate the devices found in the given context.

Parameters

ctx	A pointer to an iio_context structure

Returns

The number of devices found

iio_context_get_name()

__api __pure const char* iio_context_get_name

(

const struct iio_context *

ctx

)

Get the name of the given context.

Parameters

ctx	A pointer to an iio_context structure

Returns

A pointer to a static NULL-terminated string

NOTE:The returned string will be local, xml or network when the context has been created with the local, xml and network backends respectively.

iio_context_get_version()

__api int iio_context_get_version	(	const struct iio_context *	ctx,
		unsigned int *	major,
		unsigned int *	minor,
		char	git_tag[8]
	)

Get the version of the backend in use.

Parameters

ctx	A pointer to an iio_context structure
major	A pointer to an unsigned integer (NULL accepted)
minor	A pointer to an unsigned integer (NULL accepted)
git_tag	A pointer to a 8-characters buffer (NULL accepted)

Returns

On success, 0 is returned

On error, a negative errno code is returned

iio_context_get_xml()

__api __pure const char* iio_context_get_xml

(

const struct iio_context *

ctx

)

Obtain a XML representation of the given context.

Parameters

ctx	A pointer to an iio_context structure

Returns

A pointer to a static NULL-terminated string

iio_context_set_timeout()

__api int iio_context_set_timeout	(	struct iio_context *	ctx,
		unsigned int	timeout_ms
	)

Set a timeout for I/O operations.

Parameters

ctx	A pointer to an iio_context structure
timeout_ms	A positive integer representing the time in milliseconds after which a timeout occurs. A value of 0 is used to specify that no timeout should occur.

Returns

On success, 0 is returned

On error, a negative errno code is returned

iio_create_context_from_uri()

__api struct iio_context* iio_create_context_from_uri

(

const char *

uri

)

Create a context from a URI description.

Parameters

uri	A URI describing the context location

Returns

On success, a pointer to a iio_context structure

On failure, NULL is returned and errno is set appropriately

iio_create_default_context()

__api struct iio_context* iio_create_default_context

(

void

)

Create a context from local or remote IIO devices.

Returns

On success, A pointer to an iio_context structure

On failure, NULL is returned and errno is set appropriately

NOTE: This function will create a network context if the IIOD_REMOTE environment variable is set to the hostname where the IIOD server runs. If set to an empty string, the server will be discovered using ZeroConf. If the environment variable is not set, a local context will be created instead.

iio_create_local_context()

__api struct iio_context* iio_create_local_context

(

void

)

Create a context from local IIO devices (Linux only)

Returns

On success, A pointer to an iio_context structure

On failure, NULL is returned and errno is set appropriately

iio_create_network_context()

__api struct iio_context* iio_create_network_context

(

const char *

host

)

Create a context from the network.

Parameters

host	Hostname, IPv4 or IPv6 address where the IIO Daemon is running

Returns

On success, a pointer to an iio_context structure

On failure, NULL is returned and errno is set appropriately

iio_create_xml_context()

__api struct iio_context* iio_create_xml_context

(

const char *

xml_file

)

Create a context from a XML file.

Parameters

xml_file

Path to the XML file to open

Returns

On success, A pointer to an iio_context structure

On failure, NULL is returned and errno is set appropriately

NOTE: The format of the XML must comply to the one returned by iio_context_get_xml.

iio_create_xml_context_mem()

__api struct iio_context* iio_create_xml_context_mem	(	const char *	xml,
		size_t	len
	)

Create a context from XML data in memory.

Parameters

xml	Pointer to the XML data in memory
len	Length of the XML string in memory (excluding the final \0)

Returns

On success, A pointer to an iio_context structure

On failure, NULL is returned and errno is set appropriately

NOTE: The format of the XML must comply to the one returned by iio_context_get_xml