How to fill a char array in C

Question

Starting from

char tval[20] = "temp:26.62";

how can I add a space character until tval is filled? I need that in the end to obtain this:

char tval[20] = "temp:26.62          ";

Answer 1

Like this, probably

size_t prevlen = strlen(tval);
memset(tval + prevlen, ' ', 19 - prevlen);
*(tval + 19) = '\0';