URI 3 REDLAND Library
URI URI class

## Synopsis

    typedef             librdf_uri;
    librdf_uri*         librdf_new_uri                      (librdf_world *world,
                                                             unsigned char *uri_string);
    librdf_uri*         librdf_new_uri_from_uri             (librdf_uri *old_uri);
    librdf_uri*         librdf_new_uri_from_uri_local_name  (librdf_uri *old_uri,
                                                             unsigned char *local_name);
    void                librdf_free_uri                     (librdf_uri *uri);
    unsigned char*      librdf_uri_as_string                (librdf_uri *uri);
    unsigned char*      librdf_uri_as_counted_string        (librdf_uri *uri,
                                                             size_t *len_p);
    void                librdf_uri_print                    (librdf_uri *uri,
                                                             FILE *fh);
    unsigned char*      librdf_uri_to_string                (librdf_uri *uri);
    unsigned char*      librdf_uri_to_counted_string        (librdf_uri *uri,
                                                             size_t *len_p);
    int                 librdf_uri_equals                   (librdf_uri *first_uri,
                                                             librdf_uri *second_uri);
    int                 librdf_uri_is_file_uri              (librdf_uri *uri);
    const char*         librdf_uri_to_filename              (librdf_uri *uri);
    librdf_uri*         librdf_new_uri_normalised_to_base   (unsigned char *uri_string,
                                                             librdf_uri *source_uri,
                                                             librdf_uri *base_uri);
    librdf_uri*         librdf_new_uri_relative_to_base     (librdf_uri *base_uri,
                                                             unsigned char *uri_string);
    librdf_uri*         librdf_new_uri_from_filename        (librdf_world *world,
                                                             const char *filename);
    int                 librdf_uri_compare                  (librdf_uri *uri1,
                                                             librdf_uri *uri2);
    int                 (*librdf_uri_filter_func)           (void *user_data,
                                                             librdf_uri *uri);

## Description

A class for absolute URIs and relative URI computation utility functions. Only absolute URIs are provided, with no current access to internals of URIs such as URI scheme, path, authority. Relative URIs can be generated against some base or turned to and from local filenames.

## Details

### librdf_uri

    typedef struct librdf_uri_s librdf_uri;

Redland URI class.

librdf_uri

### librdf_new_uri ()

    librdf_uri*         librdf_new_uri                      (librdf_world *world,
                                                             unsigned char *uri_string);

Constructor - create a new librdf_uri object from a URI string.

A new URI is constructed from a copy of the string. If the string is a NULL pointer or empty (0 length) then the result is NULL.

world :

  redland world object

uri_string :

  URI in string form

Returns :

  a new librdf_uri object or NULL on failure

librdf_new_uri

### librdf_new_uri_from_uri ()

    librdf_uri*         librdf_new_uri_from_uri             (librdf_uri *old_uri);

Copy constructor - create a new librdf_uri object from an existing librdf_uri object.

old_uri :

  librdf_uri object

Returns :

  a new librdf_uri object or NULL on failure

librdf_new_uri_from_uri

### librdf_new_uri_from_uri_local_name ()

    librdf_uri*         librdf_new_uri_from_uri_local_name  (librdf_uri *old_uri,
                                                             unsigned char *local_name);

Copy constructor - create a new librdf_uri object from an existing librdf_uri object and a local name.

old_uri :

  librdf_uri object

local_name :

  local name to append to URI

Returns :

  a new librdf_uri object or NULL on failure

librdf_new_uri_from_uri_local_name

### librdf_free_uri ()

    void                librdf_free_uri                     (librdf_uri *uri);

Destructor - destroy a librdf_uri object.

uri :

  librdf_uri object

librdf_free_uri

### librdf_uri_as_string ()

    unsigned char*      librdf_uri_as_string                (librdf_uri *uri);

Get a pointer to the string representation of the URI.

Returns a shared pointer to the URI string representation. Note: does not allocate a new string so the caller must not free it.

uri :

  librdf_uri object

Returns :

  string representation of URI

librdf_uri_as_string

### librdf_uri_as_counted_string ()

    unsigned char*      librdf_uri_as_counted_string        (librdf_uri *uri,
                                                             size_t *len_p);

Get a pointer to the string representation of the URI with length.

Returns a shared pointer to the URI string representation. Note: does not allocate a new string so the caller must not free it.

uri :

  librdf_uri object

len_p :

  pointer to location to store length

Returns :

  string representation of URI

librdf_uri_as_counted_string

### librdf_uri_print ()

    void                librdf_uri_print                    (librdf_uri *uri,
                                                             FILE *fh);

Print the URI to the given file handle.

uri :

  librdf_uri object

fh :

  file handle

librdf_uri_print

### librdf_uri_to_string ()

    unsigned char*      librdf_uri_to_string                (librdf_uri *uri);

Format the URI as a string.

Note: this method allocates a new string since this is a _to_ method and the caller must free the resulting memory.

uri :

  librdf_uri object

Returns :

  string representation of the URI or NULL on failure

librdf_uri_to_string

### librdf_uri_to_counted_string ()

    unsigned char*      librdf_uri_to_counted_string        (librdf_uri *uri,
                                                             size_t *len_p);

Format the URI as a counted string.

Note: this method allocates a new string since this is a _to_ method and the caller must free the resulting memory.

uri :

  librdf_uri object

len_p :

  pointer to location to store length

Returns :

  string representation of the URI or NULL on failure

librdf_uri_to_counted_string

### librdf_uri_equals ()

    int                 librdf_uri_equals                   (librdf_uri *first_uri,
                                                             librdf_uri *second_uri);

Compare two librdf_uri objects for equality.

first_uri :

  librdf_uri object 1

second_uri :

  librdf_uri object 2

Returns :

  non 0 if the objects are equal

librdf_uri_equals

### librdf_uri_is_file_uri ()

    int                 librdf_uri_is_file_uri              (librdf_uri *uri);

Test if a URI points to a filename.

uri :

  librdf_uri object

Returns :

  Non zero if the URI points to a file

librdf_uri_is_file_uri

### librdf_uri_to_filename ()

    const char*         librdf_uri_to_filename              (librdf_uri *uri);

Return pointer to filename of URI.

Returns a pointer to a newly allocated buffer that the caller must free. This will fail if the URI is not a file: URI. This can be checked with librdf_uri_is_file_uri

uri :

  librdf_uri object

Returns :

  pointer to filename or NULL on failure

librdf_uri_to_filename

### librdf_new_uri_normalised_to_base ()

    librdf_uri*         librdf_new_uri_normalised_to_base   (unsigned char *uri_string,
                                                             librdf_uri *source_uri,
                                                             librdf_uri *base_uri);

Constructor - create a new librdf_uri object from a URI string stripped of the source URI, made relative to the base URI.

uri_string :

  URI in string form

source_uri :

  source URI to remove

base_uri :

  base URI to add

Returns :

  a new librdf_uri object or NULL on failure

librdf_new_uri_normalised_to_base

### librdf_new_uri_relative_to_base ()

    librdf_uri*         librdf_new_uri_relative_to_base     (librdf_uri *base_uri,
                                                             unsigned char *uri_string);

Constructor - create a new librdf_uri object from a URI string relative to a base URI.

An empty uri_string or NULL is equivalent to librdf_new_uri_from_uri(base_uri)

base_uri :

  absolute base URI

uri_string :

  relative URI string

Returns :

  a new librdf_uri object or NULL on failure

librdf_new_uri_relative_to_base

### librdf_new_uri_from_filename ()

    librdf_uri*         librdf_new_uri_from_filename        (librdf_world *world,
                                                             const char *filename);

Constructor - create a new librdf_uri object from a filename.

world :

  Redland librdf_world object

filename :

  filename

Returns :

  a new librdf_uri object or NULL on failure

librdf_new_uri_from_filename

### librdf_uri_compare ()

    int                 librdf_uri_compare                  (librdf_uri *uri1,
                                                             librdf_uri *uri2);

Compare two librdf_uri objects lexicographically.

A NULL URI is always less than (never equal to) a non-NULL URI.

uri1 :

  librdf_uri object 1 or NULL

uri2 :

  librdf_uri object 2 or NULL

Returns :

  <0 if uri1 is less than uri2, 0 if equal, >0 if uri1 is greater than uri2

librdf_uri_compare

### librdf_uri_filter_func ()

    int                 (*librdf_uri_filter_func)           (void *user_data,
                                                             librdf_uri *uri);

Callback function for `librdf_parser_set_uri_filter()`

user_data :

  user data

uri :

  librdf_uri URI to check

Returns :

  non-0 to filter the URI

librdf_uri_filter_func