include c:\cxpl\codes;  \intrinsic 'code' declarations
string 0;               \use zero-terminated strings

func StrLen(A);         \Return number of characters in a string
char A;
int  I;
for I:= 0 to -1>>1-1 do
    if A(I) = 0 then return I;

func StrFind(A, B);     \Search for string B in string A
\Returns index of first occurrence of string B in A, or -1 if B is not found
char A, B;              \strings to be compared
int  LA, LB, I, J;
[LA:= StrLen(A);
 LB:= StrLen(B);
 for I:= 0 to LA-LB do
    [for J:= 0 to LB-1 do
        if B(J) # A(J+I) then J:= LB+1;
    if J = LB then return I;    \found
    ];
return -1;
];

char Str;  int I, J;
[Str:= "pack my box with";
\       0123456789012345
Text(0, if StrFind(Str, "pack") = 0 then "yes" else "no");  CrLf(0);    \1.
Text(0, if StrFind(Str,  "ack") = 0 then "yes" else "no");  CrLf(0);
I:= StrFind(Str, "x w");
Text(0, if I >= 0 then "yes" else "no");                                \2.
Text(0, ", at offset ");  IntOut(0, I);  CrLf(0);
I:= 0;  J:= 0;          \offsets of space characters
loop    [I:= StrFind(Str+J, " ");
        if I < 0 then quit;
        IntOut(0, I+J); ChOut(0, ^ );
        J:= J+I+1;
        ];
CrLf(0);
Text(0, if StrFind(Str, "X w") >= 0 then "yes" else "no");  CrLf(0);
Text(0, if StrFind(Str, "with") = StrLen(Str)-StrLen("with") then "yes" else "no");  CrLf(0); \3.
Text(0, if StrFind(Str, "x w" ) = StrLen(Str)-StrLen("x w" ) then "yes" else "no");  CrLf(0);
]