Tracker SPARQL Library Reference Manual: Utilities

## Utilities Utilities — General purpose utilities provided by the library |

## Stability Level

Stable, unless otherwise indicated

## Synopsis

    #include <tracker-sparql.h>

    gchar *             tracker_sparql_get_uuid_urn         (void);
    gchar *             tracker_sparql_escape_string        (const gchar *literal);
    gchar *             tracker_sparql_escape_uri_printf    (const gchar *format,
                                                             ...);
    gchar *             tracker_sparql_escape_uri_vprintf   (const gchar *format,
                                                             va_list args);

## Description

The libtracker-sparql utilities help in the creation of proper SPARQL queries.

## Details

### tracker_sparql_get_uuid_urn ()

    gchar *             tracker_sparql_get_uuid_urn         (void);

Generates a unique universal identifier to be used for urns when inserting SPARQL into the database. The string returned is in lower case and has the format "urn:uuid:%s" where %s is the uuid generated.

Returns : | a newly-allocated string. The returned string should be freed with `g_free()` when no longer needed.

Since 0.10

### tracker_sparql_escape_string ()

    gchar *             tracker_sparql_escape_string        (const gchar *literal);

Escapes a string so that it can be used in a SPARQL query.

`literal` : | a string to escape
Returns : | a newly-allocated string with the escaped version of `literal`. The returned string should be freed with `g_free()` when no longer needed.

Since 0.10

### tracker_sparql_escape_uri_printf ()

    gchar *             tracker_sparql_escape_uri_printf    (const gchar *format,
                                                             ...);

Calls `tracker_sparql_escape_uri_vprintf()` with the @... supplied.

`format` : | a standard `printf()` format string, but notice string precision pitfalls documented in `g_strdup_printf()`
`...` : | the parameters to insert into the format string
Returns : | a newly-allocated string holding the result.The returned string should be freed with `g_free()` when no longer needed.

Since 0.10

### tracker_sparql_escape_uri_vprintf ()

    gchar *             tracker_sparql_escape_uri_vprintf   (const gchar *format,
                                                             va_list args);

Similar to the standard C `vsprintf()` function but safer, since it calculates the maximum space required and allocates memory to hold the result.

The result is escaped using `g_uri_escape_string()`.

`format` : | a standard `printf()` format string, but notice string precision pitfalls documented in `g_strdup_printf()`
`args` : | the list of parameters to insert into the format string
Returns : | a newly-allocated string holding the result. The returned string should be freed with `g_free()` when no longer needed.

Since 0.10