This function is similar to strcmp(),
with the difference that you can specify the (upper limit of
the) number of characters (len) from each string to be used in
the comparison. If any of the strings is shorter than len, then the length of that
string will be used for the comparison.
Returns 0 if str1
is less than str2; 0
if str1 is greater than str2, and 0 if they are
equal.
Note that this comparison is case sensitive.
See also ereg(),
strncasecmp(), strcasecmp(), substr(),
stristr(), strcmp(), and
strstr().