Is there an easy way to read a string from a file and read it in little endian format to convert to int?

I have some old file formats that I want to convert, and header information is stored in little endian format.  So far I have something like this for a WORD (2-bytes):

Stdio.File fp;

fp=Stdio.File(filename,"r");

string str=fp->read(2);

int res=array_sscanf(reverse(str),"%2c")[0];

Trying to find an easy way to make it variable, like 2 or 4 byte ints (there are some DWORDs in the file too).  array_sscanf doesn't take parameters for the format, so I can't do "%*c",2 .

Thanks..