Base functions

Retrieve a printer's CAPS Printer Device Parameter Directory. More...

Functions
struct caps_si_handle *	caps_si_create (void)
void	caps_si_destroy (struct caps_si_handle *h)
int	caps_si_char_device_node_check (struct caps_si_handle *h, const char *f)
char *	caps_si_dir_from_node_retrieve (struct caps_si_handle *h, const char *f)
char *	caps_si_dir_from_name_retrieve (struct caps_si_handle *h, const char *n)

Detailed Description

The base functions to work with the library and discover a printer device's specific CAPS Printer Device Parameter Directory.

Function Documentation

caps_si_create()

struct caps_si_handle * caps_si_create

(

void

)

Initialize the library prior use

Returns

Library instance to be used by all other functions in this library

Note

Does not return in case of memory failure

Postcondition

The returned library instance handle needs to be freed after use via caps_si_destroy()

caps_si_destroy()

void caps_si_destroy

(

struct caps_si_handle *

h

)

Clean up resources

Parameters

[in]

h

Library instance

Note

This call will also close error message catching. Refer Error message handling for details.

caps_si_char_device_node_check()

int caps_si_char_device_node_check	(	struct caps_si_handle *	h,
		const char *	f
	)

Check, if the given path/filename is a character device node

Parameters

[in]	h	Library instance
[in]	f	Path to check

Return values

1	f points to a character device node
0	f doesn't point to a character device node
-EINVAL	f is invalid

Precondition

h must be a valid library instance handle returned by caps_si_create() call

caps_si_dir_from_node_retrieve()

char * caps_si_dir_from_node_retrieve	(	struct caps_si_handle *	h,
		const char *	f
	)

Retrieve the CAPS Printer Device Parameter Directory from the device node

Parameters

[in]	h	Library instance
[in]	f	Device node in the form "/dev/...."

Return values

PATH	Path to the corresponding CAPS Printer Device Parameter Directory
NULL	No corresponding printer device with devnode f found

Note

This function creates readable error messages (refer caps_si_error_messages_catch())

Precondition

f must be a printer device node. Check first with caps_si_char_device_node_check()

h must be a valid library instance handle returned by caps_si_create() call

Postcondition

The returned directory path string must be freed after use.

caps_si_dir_from_name_retrieve()

char * caps_si_dir_from_name_retrieve	(	struct caps_si_handle *	h,
		const char *	n
	)

Retrieve the CAPS Printer Device Parameter Directory from the printer's name

Parameters

[in]	h	Library instance
[in]	n	Name of the printer like the capsprinter list command returns it

Return values

PATH	Path to the corresponding CAPS Printer Device Parameter Directory
NULL	No corresponding printer device with name n found

Note

This function creates readable error messages (refer caps_si_error_messages_catch())

Precondition

n must be a name string

h must be a valid library instance handle returned by caps_si_create() call

Postcondition

The returned directory path string must be freed after use.