Smac defines classical strings functions (read your local man for more information):
char * strcat(char * s1, char * s2)
char * strchr(char * s, int c)
int strcmp(char * s1, char * s2)
char * strcpy(char * s1, char * s2)
char * strcspn(char * s1, char * s2)
char * strncat(char * s1, char * s2, int n)
int strncmp(char * s1, char * s2, int n)
char * strncpy(char * s1, char * s2, int n)
char * strpbrk(char * s1, char * s2)
char * strrchr(char * s, int c)
int strspn(char * s1, char * s2)
char * strstr(char s1, char * s2)
char * strtok(char s1, char * s2)
char * rindex(char * s, int c)