Developer Guide and Reference

ID 767251
Date 10/31/2024
Public
Document Table of Contents

Rules for Unformatted Direct-Access READ Statements

Unformatted, direct-access READ statements transfer binary data (without translation) between the current record and the entities specified in the I/O list. Only one record is read.

Objects of intrinsic or derived types can be transferred.

For data transfer, the file must be positioned so that the record read is an unformatted record or an end-of-file record.

The unformatted, direct-access READ statement reads a single record. Each value in the record must be of the same type as the corresponding entity in the input list, unless the value is real or complex.

If the value is real or complex, one complex value can correspond to two real list entities, or two real values can correspond to one complex list entity. The corresponding values and entities must have the same kind parameter.

If the number of I/O list items is less than the number of fields in an input record, the statement ignores the excess fields. If the number of I/O list items is greater than the number of fields in an input record, an error occurs.

If the file is connected for formatted, list-directed, or namelist I/O, unformatted data transfer is prohibited.

Examples

The following example shows unformatted, direct-access READ statements:


  READ (1, REC=10) LIST(1), LIST(8)
  READ (4, REC=58, IOSTAT=K, ERR=500) (RHO(N), N=1,5)