Count the number of set bits (population counting) in a string. Unlike bitcount, it take part of the string by
start- Optional, inclusive, if start is negative, count from start'th character from the end of string.
size- Optional, if size is negative, then that many characters will be omitted from the end of string.
The number of bits set to 1.
ssdb 127.0.0.1:8888> set a 123 ok (0.000 sec) ssdb 127.0.0.1:8888> countbit a 0 1 3 (0.000 sec) ssdb 127.0.0.1:8888> bitcount a 0 1 6 (0.000 sec) ssdb 127.0.0.1:8888>