Learn PLI-MAINFRAME with Real Code Examples

HELLO: PROCEDURE;
    PUT SKIP LIST('Hello, PL/I World!');
END HELLO;

Display a simple greeting message.

ASSIGN-VARS: PROCEDURE;
    DECLARE A FIXED BINARY(31);
    DECLARE B FIXED BINARY(31);
    A = 10;
    B = 20;
    PUT SKIP LIST('A + B = ', A + B);
END ASSIGN-VARS;

Assign values to variables and display the result.

CHECK-NUMBER: PROCEDURE;
    DECLARE NUM FIXED BINARY(31) INIT(-5);
    IF NUM >= 0 THEN
        PUT SKIP LIST('Number is positive.');
    ELSE
        PUT SKIP LIST('Number is negative.');
END CHECK-NUMBER;

Check if a number is positive or negative.

LOOP-EXAMPLE: PROCEDURE;
    DECLARE I FIXED BINARY(31);
    DO I = 1 TO 5;
        PUT SKIP LIST('Number: ', I);
    END;
END LOOP-EXAMPLE;

Print numbers from 1 to 5 using DO loop.

ARRAY-SUM: PROCEDURE;
    DECLARE NUMS(5) FIXED BINARY(31) INIT(1,2,3,4,5);
    DECLARE TOTAL FIXED BINARY(31) INIT(0);
    DO I = 1 TO 5;
        TOTAL = TOTAL + NUMS(I);
    END;
    PUT SKIP LIST('Total Sum: ', TOTAL);
END ARRAY-SUM;

Sum values in an array of integers.

STRING-CONCAT: PROCEDURE;
    DECLARE FIRST CHAR(10) INIT('John');
    DECLARE LAST CHAR(10) INIT('Doe');
    DECLARE FULL CHAR(21);
    FULL = FIRST || ' ' || LAST;
    PUT SKIP LIST('Full Name: ', FULL);
END STRING-CONCAT;

Concatenate first and last name into full name.

FILE-WRITE: PROCEDURE;
    DECLARE F FILE OUTPUT;
    OPEN FILE(F) TITLE('output.txt');
    PUT FILE(F) LIST('Hello, PL/I File!');
    CLOSE FILE(F);
END FILE-WRITE;

Write a simple message to a file.

SUBSTRING-EX: PROCEDURE;
    DECLARE STR CHAR(20) INIT('PL/I Programming');
    DECLARE SUB CHAR(10);
    SUB = SUBSTR(STR, 1, 3);
    PUT SKIP LIST('Substring: ', SUB);
END SUBSTRING-EX;

Extract a substring from a string variable.

COND-ASSIGN: PROCEDURE;
    DECLARE X FIXED BINARY(31) INIT(5);
    DECLARE Y FIXED BINARY(31);
    Y = (X > 0) ? 100 : -100;
    PUT SKIP LIST('Y = ', Y);
END COND-ASSIGN;

Assign a value based on a condition.

MATRIX-EX: PROCEDURE;
    DECLARE MAT(2,2) FIXED BINARY(31) INIT((1,2),(3,4));
    DO I = 1 TO 2;
        DO J = 1 TO 2;
            PUT SKIP LIST('MAT(', I, ',', J, ') = ', MAT(I,J));
        END;
    END;
END MATRIX-EX;

Initialize and display a 2x2 matrix.