Set Status Words

These routines enable the user to change defaults kept in the status words, such as the maximum length of the physical block he wants to read, the maximum length of the logical record, and so on.

Normally, control words should be changed before any writing on that unit takes place. Otherwise, it is strongly recommended to make a close call to the corresponding unit (EPCLOS) beforehand in order to avoid problems. The user should be fully aware of what he is doing, and foresee the possible effects of any change.

For the use of EPSETA, and EPSETC (setting more than one word), it is recommended to get hold of the existing status words by calls to EPGETA or EPGETC, modify where desired, and restore.

CALL EPSETW (LUNIT,NUMBER,IWORD,IERR*)

Input parameters:

LUNIT

logical unit number

NUMBER

Number of the status word to change.

IWORD

new value of the status word.

Output parameter:

IERR

error flag. See separate list.

CALL EPSETA (LUNIT,NW,IWORDS,IERR*)

Input parameters:

LUNIT

logical unit number

NW

Number of status words to set (always start at word 1).

IWORDS

new value for the status words 1..NW.

Output parameter:

IERR

error flag. See separate list.

CALL EPSETC (NW,IW)

Input parameters:

NW

no. of overall control words to set (from 1 up to NCONT)

IW

new overall control words.

Handle with care!

CALL EPADDH (LUNIT,NH,IH,*IBUF*,IERR*)

Adds a user portion to the standard physical header. The current block is written out beforehand if not empty.

The physical header is reset to the standard header after a rewind.

Input parameters:

LUNIT

logical unit number

NH

number of 16-bit words to add (0 resets the standard physical header).

IH

user physical header words to add (16-bit, right adjusted, 0 filled)

Input/Output buffer:

User provided unit buffer. Must not be touched by the user.

Output parameter:

IERR

error flag. See separate list.

CALL EPUPDH (LUNIT,NH,IH,IBUF,IERR)

Updates the (optional) user portion of the physical block header. The necessary space for this optional portion must have been reserved by the user through a previous call to EPADDH (typically once at the start of the job). Whereas a call to EPADDH causes the existing (if any) block to be written out, EPUPDH does not have this effect.

Input parameters:

LUNIT

logical unit number

NH

no. of user words in header to be updated. It is cut at the actual no. of extra user words available in the physical block header.

IH

Array containing the new values. Words 1..NH of IH will replace the current words 1..NH of the user portion in the header.

Input/Output buffer:

User provided unit buffer. Must not be touched by the user.

Output parameter:

IERR

error flag. See separate list.