The Unix version is restricted to fixed length blocks with full padding which is in any case the EPIO default. If a different blocksize than the EPIO default (1800 16-bit words) is required, it must be specified correctly in status word 1 by a call to EPSETW, e.g. for a blocksize of 1800 bytes on unit 11
CALL EPSETW(11,1,900,IERR).Unfortunately, this means that you can not give an arbitrarily large blocksize to allow your program to read files with different block sizes. Otherwise, existing applications should be portable to Unix workstations.
The choice of C or Fortran for the basic I/O can be selected using the status word 33, which is set by the user as detailed in the table below.
| Value | Type of I/O | Default filename (|lun=nn|) |
| 0 | Fortran sequential | |for0nn| |
| 1 | Fortran direct access | |epionn| |
| 2 | C using CFIO | |epionn| |
By default, status word 33 is set to 2. Although it is the old default, Value 0 is not portable and seems to give more problems. Values 1 and 2 give identical formats on most systems and are portable.
The association with real filenames can be made in several ways:
CALL EPDEFU(LUN,'epdata/test1',IERR)
ln command before execution, e.g.
ln epdata/test epio01and follow it by:
CALL EPREAD(1,MODE,NW,IREC,IBUF,IERR)
mv) or copy (cp) the file to an EPIO name epionn.