def read_short(f, endian):
"""Read a 2-Byte integer from file f
with a given endianness (byte order).
endian can be either 'big' or 'little'.
"""
if (endian != 'little') and (endian != 'big'):
_logger.debug('File address:', f.tell())
raise ByteOrderError(endian)
else:
data = f.read(2) # hexadecimal representation
if endian == 'big':
s = B_short
elif endian == 'little':
s = L_short
return s.unpack(data)[0] # struct.unpack returns a tuple
def read_long(f, endian):
"""Read a 4-Byte integer from file f
with a given endianness (byte order).
endian can be either 'big' or 'little'.
"""
if (endian != 'little') and (endian != 'big'):
_logger.debug('File address:', f.tell())
raise ByteOrderError(endian)
else:
data = f.read(4)
if endian == 'big':
s = B_long
elif endian == 'little':
s = L_long
return s.unpack(data)[0]
def read_double(f, endian):
"""Read a 8-Byte floating point from file f
with a given endianness (byte order).
endian can be either 'big' or 'little'.
"""
if (endian != 'little') and (endian != 'big'):
_logger.debug('File address:', f.tell())
raise ByteOrderError(endian)
else:
data = f.read(8)
if endian == 'big':
s = B_double
elif endian == 'little':
s = L_double
return s.unpack(data)[0]