Missing ANSI functions?

[Jon & Sue Trauntvein]

Greetings,
 
I have been recently porting some code that I 
had originally written for Visual C++. In so doing, I have come accross some 
functions that I thought were a part of the ANSI C library but don't appear to 
be apart of the standard library distributed with the Cygnus compiler. These 
functions are strrev (reverse a "C" string in place) and itoa (convert 
a signed integer to an ASCII string). Is there something that I am doing wrong 
or are these functions trully missing?
 
Regards,
 
Jon Trauntvein