Difference between revisions of "Truxton location get file id"

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=Sample=
 
=Sample=
 
<source lang="C" highlight="11">
 
<source lang="C" highlight="11">
void dump_location(uint64_t location_handle)
+
void dump_location( uint64_t location_handle )
 
{
 
{
 
   double value = 0;
 
   double value = 0;
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}
 
}
 
</source>
 
</source>
 +
 +
The <code>PRIu64</code> in the sample code above is a standard way of [https://en.wikipedia.org/wiki/C_data_types#Printf_and_scanf_format_specifiers formatting] a 64-bit unsigned integer in C.
 +
Over the years, different compilers on different operating systems used different format specifiers for things, these <code>PRI</code> macros, along with some tricky string concatenation the compilers perform for you, allow you to maintain a single code base without a bunch of macro magic.

Revision as of 07:21, 6 February 2021

This retrieves the GUID of the file the location came from. This corresponds to the [FileID] column of the [Location] table. The value should be present in the [ID] column of the [File] table.

Syntax

void truxton_location_get_file_id( uint64_t location_handle, char * destination_string, size_t max_size );

Parameters

location_handle

This handle comes from calling truxton_location_create() or truxton_child_file_create_location()

destination_string

The string to be written to.

max_size

The maximum number of characters that can be written to destination_string.

Sample

void dump_location( uint64_t location_handle )
{
   double value = 0;
   uint64_t ticks = 0;
   char guid_string[ 40 ];
   char label[ 256 ];

   truxton_location_get_label(location_handle, label, sizeof( label ));
   printf( "%s\n", label );

   truxton_location_get_file_id(location_handle, guid_string, sizeof( guid_string ));
   printf( "File ID: %s\n", guid_string );

   truxton_location_get_media_id(location_handle, guid_string, sizeof( guid_string ));
   printf( "Media ID: %s\n", guid_string );

   value = truxton_location_get_latitude( location_handle );
   printf( "Latitude: %lf\n", value );

   value = truxton_location_get_longitude( location_handle );
   printf( "Longitude: %lf\n", value );

   value = truxton_location_get_altitude( location_handle );
   printf( "Altitude: %lf meters\n", value );

   ticks = truxton_location_get_type( location_handle );
   printf( "Type: %" PRIu64 "\n", ticks );

   ticks = truxton_location_get_when( location_handle );
   printf( "Ticks: %" PRIu64 "\n", ticks );
}

The PRIu64 in the sample code above is a standard way of formatting a 64-bit unsigned integer in C. Over the years, different compilers on different operating systems used different format specifiers for things, these PRI macros, along with some tricky string concatenation the compilers perform for you, allow you to maintain a single code base without a bunch of macro magic.