Fortran Unformatted Sequential Record Marker Portability

Fortran Unformatted Sequential Files

The Fortran standard permits processor-dependent record markers for unformatted sequential files, so compilers may use different byte widths and byte orders. A restored backup can appear structurally valid while containing different record boundaries on another platform.

Verification Constraint

The INQUIRE statement confirms access mode and formatting but does not expose record-marker size or endianness at runtime. Without knowing the writing compiler's convention, byte-level checksums of the restored file cannot reliably prove logical data integrity.

Goal: determine whether an existing unformatted sequential file can be verified portably after restoration without external metadata.

Is there a standard-compliant way to query record-marker conventions from an existing file? If not, what application-level metadata is necessary to validate restored records across compilers?