http://kor.i2p/books/The%20C%20Programming%20Language%20by%20K&R/chapter7.html
In the following, s and t are char * 's, and c and n are int s. strcat(s,t) concatenate t to end of s strncat(s,t,n) concatenate n characters of t to end of s strcmp(s,t) return negative, zero, or positive for s < t , s == t , s > t strncmp(s,t,n) same as strcmp but only in first n characters strcpy(s,t) copy t to s strncpy(s,t,n) copy at most n characters of t to s strlen(s) return length of s strchr(s,c)...