C's strtok() and read only string literals

Question

char *strtok(char *s1, const char *s2)

repeated calls to this function break string s1 into \"tokens\"--that is the string is broken into substr

Answer 1

In brief:

char *s = "HAPPY DAY";
printf("\n %s ", s);

s = "NEW YEAR"; /* Valid */
printf("\n %s ", s);

s[0] = 'c'; /* Invalid */