Difference between revisions of "Truxton file get disk offset"

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This retrieves the byte offset into the original disk image where this file's contents began.
 
This retrieves the byte offset into the original disk image where this file's contents began.
It corresponds to the <code>PhysicalDiskOffset</code> column of the <code>[[File Table | File]]</code> table.
+
It corresponds to the <code>[PhysicalDiskOffset]</code> column of the <code><nowiki>[</nowiki>[[File Table|File]]<nowiki>]</nowiki></code> table.
  
 
=Syntax=
 
=Syntax=
<syntaxhighlight lang="C">
+
<source lang="C">
 
uint64_t truxton_file_get_disk_offset( uint64_t file_handle );
 
uint64_t truxton_file_get_disk_offset( uint64_t file_handle );
</syntaxhighlight>
+
</source>
  
 
=Parameters=
 
=Parameters=
Line 15: Line 15:
  
 
=Sample=
 
=Sample=
<syntaxhighlight lang="C" highlight="10">
+
<source lang="C" highlight="10">
int print_it(uint64_t truxton)
+
void print_it( uint64_t truxton )
 
{
 
{
   uint64_t file = truxton_file_open_md5(truxton, "9ec8fb6095c35eff2b236863b7caaf10");
+
   uint64_t file = truxton_file_open_md5( truxton, "9ec8fb6095c35eff2b236863b7caaf10" );
  
 
   if ( file != 0 )
 
   if ( file != 0 )
 
   {
 
   {
       return(0);
+
       return;
 
   }
 
   }
  
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   truxton_file_free( file );
 
   truxton_file_free( file );
 
}
 
}
</syntaxhighlight>
+
</source>
  
 
Note, the <code>PRIu64</code> in the sample code above is the new standard way of [https://en.wikipedia.org/wiki/C_data_types#Printf_and_scanf_format_specifiers formatting] a 64-bit integer in C.
 
Note, the <code>PRIu64</code> in the sample code above is the new standard way of [https://en.wikipedia.org/wiki/C_data_types#Printf_and_scanf_format_specifiers formatting] a 64-bit 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.
 
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.

Latest revision as of 04:38, 13 February 2021

This retrieves the byte offset into the original disk image where this file's contents began. It corresponds to the [PhysicalDiskOffset] column of the [File] table.

Syntax

uint64_t truxton_file_get_disk_offset( uint64_t file_handle );

Parameters

file_handle

The handle created by the truxton_file_open_id or truxton_file_open_md5 call.

Return value

The byte offset in the disk image where this file's contents began.

Sample

void print_it( uint64_t truxton )
{
   uint64_t file = truxton_file_open_md5( truxton, "9ec8fb6095c35eff2b236863b7caaf10" );

   if ( file != 0 )
   {
      return;
   }

   uint64_t offset = truxton_file_get_disk_offset( file );

   printf( "File began at %" PRIu64 "\n", offset );

   truxton_file_free( file );
}

Note, the PRIu64 in the sample code above is the new standard way of formatting a 64-bit 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.