There is not fread(fileid, 'r'), there is a fopen(filename, 'r') but that tells us nothing about how you read the file initially.
Assuming that you've read the file as fread(fileid), then what you've got is the sequence of bytes (inefficiently stored as double) and converting that back to characters may just be simply:
chardata = char(aVec);
if you want to split that into lines:
lines = strsplit(char(aVec), {'\n', '\r'})
The above assumes that the file text encoding is the same as that used by matlab. If not, you'll have to use native2unicode with the proper encoding first.
