Codepoint U+00A4 --> hex 0xA4 --> binary 10100100

We need to store 10100100 in the UTF-8 bytes:

110..... 10.....

We distribute 10100100 over the 'points' in the two bytes:

110 00010 10 100100

So U+00A4 in UTF-8 becomes 1100010 10100100 or 0xc2 0xa4.

##</code><code>##

sprintf("%c%c", 

# Build first byte by OR'ing 0xc0 (binary 11000000) with 
# the two highest order bits of the character
          (0xc0 | ($o >> 6)),

# Build the second byte by OR'ing 0x80 (binary 10000000)
# with the lower 6 bits of the character (obtained by
# AND'ing with 0x3f, 00011111)
          (0x80 | ($o & 0x3f))