WRITET Statement

Writes a record to tape.

Syntax

WRITET char-string [THEN statement(s) | ELSE statement(s)]

Syntax Elements

char-string is a DataBasic expression that evaluates to a string. This will be written as the next record on the tape.

statement(s) is either a THEN or an ELSE clause (or both). A statement must be included. The THEN clause is executed if the write is successful. The ELSE clause is executed if the tape unit has not been attached, or if the string value of char-string is a null string.

Comments

The maximum record size that can be written to tape is controlled by the ASSIGN or T-ATT command. For example, T-ATT 1 SIZE=2048  sets the maximum record size written to 2048. When writing, if necessary, records are padded to 20 bytes with segment marks; these are deleted when read.

DataBasic writes a label when the first WRITET statement is executed or when a WRITET is executed after a rewind or after an EOF has been written. If you want to write to an unlabelled tape you must either first assign/attach the tape using LABEL=0 in the ASSIGN or T-ATT command, or use RUN with the T option (unlabelled tapes can be used to ensure compatibility with previous releases and other devices).

If you have not attached the tape, the software displays the error message:

[1129] No such tape assignment exists

and your program is terminated.

For more information on tape handling, see Overview of Tape Operations.

Examples

WRITET A+5 THEN PRINT "WRITTEN TO TAPE" ELSE STOP

Writes the value of A+5 as the next record on tape and prints WRITTEN TO TAPE on the terminal.  If the tape unit is not attached or if A+5 is a null value, the program terminates.

FOR I=1 TO 5

  WRITET A(I) ELSE STOP

NEXT I

Writes the values of array elements A(1) through A(5) onto 5 tape records.  If one of the array elements has a value of '' (null) or if the tape unit is not attached, the program terminates.