strtok

strstr

#include <string.h>char *strstr(const char *str1, const char *str2);

The strstr( ) function returns a pointer to the first occurrence in the string pointed to by str1 of the string pointed to by str2. It returns a null pointer if no match is found.

Related functions are strchr( ), strcspn( ), strpbrk( ), strspn( ), strtok( ), and strrchr( ).