Edit-Directed Stream I/O

Values transmitted by edit-directed stream I/O are transmitted into fixed-length fields whose length and content are controlled by data-formats. Data-formats specifically control the type of conversion to be performed and the number of characters or digits in an input or output field. Each data-format corresponds to an element of the GET or PUT statement's value list and causes that value to be converted and transmitted. For example:

PUT FILE(F) EDIT(A,B) (F(7,2),A(6));

In this example, if A is declared fixed binary(15) and has a current value of -45, and B is declared character(4) and has a current value of HAT, the following is written into the current line of file F.

Control formats can be used to force new lines and skip parts of lines, as shown in the next example. If there are more format items than values to be transmitted in the statement's I/O list, the extra format items are ignored. For example:

PUT FILE(F) EDIT(A,B) (X(3),F(7,2),SKIP,X(4),A(6),SKIP);

Using the same values of A and B as in the previous example, the above statement produces the following:

In this example, the first line is placed at the end of the current line, and the second line starts a new output line. The PUT statement does not start another new line, because B was the last item output; hence, the PUT statement terminated before the second SKIP was executed.

Edit-directed input requires that each input line be described precisely by the controlling format. If the current input line contains fewer characters than are required to satisfy the format, additional lines are read until the format is satisfied, as shown in the following example.

GET FILE(F) EDIT (X) (A(80));

In this example, if X is declared as character(100) and the current line contains only 60 characters, the 60 characters are read, a new line is read, processing advances to the next line, and 20 additional characters are read from that line. The 80 characters thus read are then assigned to X, and 20 blanks are used to pad the value of X on the right.