Assuming you are using the standard ESP32 webserver library you could do the following:
In your handler function compare the path argument you get with
webServer.uri()
which is a char array then use int strcasecmp(const char *s1, const char *s2);
the function part would be
if (strcasecmp (webServer.uri(), "www/mysmallcapslink.html") == 0) {
... do your stuff here ...
e.g. serve the file
}
Note == 0 means the two strings (C-strings with small s) are identic (apart from the case). So url requests like
www/Mysmallcapslink.html
www/MySmallCapsLink.html
would all be handled by the same handler.
Info about srtcasecmp:
DESCRIPTION The strcasecmp() function shall compare, while ignoring differences in case, the string
pointed to by s1 to the string pointed to by s2. The strncasecmp() function shall
compare, while ignoring differences in case, not more than n bytes from the string
pointed to by s1 to the string pointed to by s2.
strncasecmp() shall behave as if the strings had been converted to lowercase and then a
byte comparison performed.
RETURN VALUE Upon completion, strcasecmp() shall return an integer greater than, equal to, or less
than 0, if the string pointed to by s1 is, ignoring case, greater than, equal to, or
less than the string pointed to by s2, respectively.