ios_inq_short_key()

IOS_$INQ_SHORT_KEY                Domain/OS                 IOS_$INQ_SHORT_KEY


NAME
     ios_$inq_short_key - return a short seek key

SYNOPSIS (C)
     #include <apollo/base.h>
     #include <apollo/ios.h>

     long ios_$inq_short_key(
          ios_$id_t &stream_id,
          ios_$pos_opt_t &position_option,
          status_$t *status)

SYNOPSIS (Pascal)
     %include '/sys/ins/base.ins.pas';
     %include '/sys/ins/ios.ins.pas';

     function ios_$inq_short_key(
          in stream_id: ios_$id_t;
          in position_option: ios_$pos_opt_t;
          out status: status_$t): integer32;

SYNOPSIS (FORTRAN)
     %include '/sys/ins/base.ins.ftn'
     %include '/sys/ins/ios.ins.ftn'

           integer*2 stream_id, position_option
           integer*4 short_key, status

           short_key = ios_$inq_short_key(stream_id, position_option, status)

DESCRIPTION
     Ios_$inq_short_key returns a short seek key for the position specified in
     position_option.  The returned seek key can be used in a call to
     ios_$seek_short_key to return the stream marker to the position specified
     in position_option.  Do not rely on the value of the returned key.  The
     only guarantee is that a call to ios_$seek_short_key will return a stream
     marker to the same record it was in when ios_$inq_short_key was called to
     obtain the key.

     stream_id
          The ID of the stream to seek on.

     position_option
          Choose one of the following positions:

          ios_$bof
               Return a short key for the beginning of the object (BOF).

          ios_$current
               Return a short key for the current record.

          ios_$eof
               Return a short key for the end of the object (EOF).

     status
          The completion status.

NOTES
     Domain/OS offers both short (4-byte) and full (8-byte) seek keys.
     Because short seek keys require half the storage space of full seek keys,
     they are useful when a program stores a large number of seek keys.  How-
     ever, short keys allow seeking to record boundaries only, while full keys
     allow seeking into records.

SEE ALSO
     ios_$inq_byte_pos, ios_$inq_full_key, ios_$inq_rec_pos, ios_$seek.
Museum
