namedstruct encapsulates struct.unpack() and struct.pack() with results accessed by name.
class namedstruct.namedstruct
__init__( description, struct_definition )
The description is used to title a dump of unpacked data.
struct_definition is a single string that defines the type and name of each field as a space seperated list. Each field's type and name are seperated by a ":". If the name is left blank that field cannot be accessed by name, useful for padding fields. If a field's type has a repeat count the value returned with be a tuple of all the fields parts.
len()
Returns the size of the struct.unpack( bytes )
Unpack the bytes into a namestruct.namestructresults object used to access the decoded fields.packer( from_unpacked=None )
Return a namedstructpacker object that can be used to pack the fields into a buffer. The optional from_unpacked will initialise the fields from a previously unpacked buffer.class namedstruct.namedstructresults
.*name*
Returns the value of the field called name.dump( writer )
Using the writer function to output a formatted dump of the whole struct.class namedstruct.namedstructpacker
.*name* = value
Assign a value to the named fieldinit_from( from_unpacked )
Assign each field from a previous unpacked buffer's namedstructresults.pack()
Pack the fields and return the bytes buffer.
import namedstruct # Windows EXE files start with a DOS header struct_windows_exe_header = namedstruct.namedstruct( 'DOS header', '<' '2s:dos_magic ' 'h:lastsize ' 'h:nblocks ' 'h:nreloc ' 'h:hdrsize ' 'h:minalloc ' 'h:maxalloc ' 'H:ss ' 'H:sp ' 'h:checksum ' 'H:ip ' 'H:cs ' 'h:relocpos ' 'h:noverlay ' '4H:reserved1 ' 'h:oem_id ' 'h:oem_info ' '10H:reserved2 ' 'L:pe_offset' ) dos_image = open( 'c:\\windows\\system32\\cmd.exe', 'rb' ).read() header = struct_windows_exe_header.unpack( dos_image[0:len(struct_windows_exe_header)] ) if debug: header.dump( print ) print( 'dos_magic %r' % (header.dos_magic,) ) print( 'PE header offer: 0x%8.8x' % (header.pe_offset,) )