>having options in cat (this is POSIX invalid)
http://pubs.opengroup.org/onlinepubs/009695399/utilities/cat.html
OPTIONS
The
cat utility shall conform to the Base Definitions volume of IEEE Std 1003.1-2001,
Section 12.2, Utility Syntax Guidelines.
The following option shall be supported:
-u Write bytes from the input file to the standard output without delay as each is read.