Function sdsrange

app/redis-6.2.6/src/sds.c:798–807

Turn the string into a smaller (or equal) string containing only the * substring specified by the 'start' and 'end' indexes. * * start and end can be negative, where -1 means the last character of the * string, -2 the penultimate character, and so forth. * * The interval is inclusive, so the start and end characters will be part * of the resulting string. * * The string is modified in-pla

 * sdsrange(s,1,-1); => "ello World"
 */
void sdsrange(sds s, ssize_t start, ssize_t end) {
    size_t newlen, len = sdslen(s);
    if (len == 0) return;
    if (start < 0)
        start = len + start;
    if (end < 0)
        end = len + end;
    newlen = (start > end) ? 0 : (end-start)+1;
    sdssubstr(s, start, newlen);
}

/* Apply tolower() to every character of the sds string 's'. */
void sdstolower(sds s) {