example 1

char s1[20]="dir/bin/app1", s2[20]="file.asm",s3[20];
char *p;
int result;

  
 Length int strlen(char *s);
       cout << strlen(s1)  <<endl;    //Output is 12.
       cout << strlen(s2)  <<endl;   //Output is 8
  
 Copy       char *strcpy(char *s1, *s2);
         strcpy(s3,s1);              //s3 ="dir/bin/app1"
  
 Concatenation  char *strcat(char *s1, *s2);
          strcat(s3,"/");
          strcat(s3,s2);       //s3 ="dir/bin/app1/file.asm"
  
 Compare      int  *strcmp(char *s1, *s2);
          result=strcmp("baker", "Baker");     //result>0
          result=strcmp("12","12");           // result=0
          result=strcmp("Joe","Joseph");      // result< 0
  
 Index char *strchr(char *s, int c);
       p=strchr(s2,'.');       // p points at '.' after file.
       if (p)
        strcpy(p,".cpp");      //s2="file.cpp"
  
 RightIndex  char *strrchr(char *s, int c);
       p=strrchr(s2,'/');       // p points at '/' after bin
       if (p)                         // Terminate string after bin.
         *p=0;                        // s2="dir/bin"
  
 Read   StreamVariable>> s
  
 Write  StreamVariable << s
        cin >> s1;              //If Input is "hello world"
        cout << s1;              // s1 is "hello"
                                      //Output is "hello"