seekdemo
  new x,p
  set p="seekfixed"
  open p:(newversion:fixed:recordsize=60)
  use p
  ; create file with 9 records of length 60 bytes each
  ; number from 0 to correspond to record offset
 
  for i=0:1:8 write $justify(i_" - [-05-|-10-|-15-|-20-|-25-|-30-|-35-|-40-|-45-|-50-|-55-|",60)
  use p:rewind
  for i=0:1:8 read x set zk=$zkey use $p write "x= ",x," $zkey= ",zk,! use p
  close p
  write !!,"** OPEN with FIXED:RECORDSIZE=60:seek=""5""",!
  open p:(fixed:recordsize=60:seek="5")
  use p
  read x set ZKEY=$zkey
  ;expect: $ZKEY= 6,0
  use $p write "x= ",x," $zkey= ",ZKEY,!
  write !,"** use with SEEK=""-3""",!
  use p:seek="-3"
  read x set ZKEY=$zkey
  ;expect: $ZKEY= 4,0
  use $p write "x= ",x," $zkey= ",ZKEY,!
  write !,"** use with SEEK=""-1"" to read from the same record. read x#20 to read a partial record",!
  use p:seek="-1"
  read x#20 set ZKEY=$zkey
  ;expect: $ZKEY= 3,20
  use $p write "x= ",x," $zkey= ",ZKEY,!
  write !,"** read x#40 to finish reading the record",!
  use p
  read x#40 set ZKEY=$zkey
  ;expect: $ZKEY= 4,0
  use $p write "x= ",x," $zkey= ",ZKEY,!
  write !,"** CLOSE NODESTROY and reOPEN with no deviceparameters",!
  close p:nodestroy
  open p
  use p
  read x set ZKEY=$zkey
  ;expect: $ZKEY= 5,0
  use $p write "x= ",x," $zkey= ",ZKEY,!
  write !,"** CLOSE NODESTROY and reOPEN with SEEK=""+2""",!
  close p:nodestroy
  open p:seek="+2"
  use p
  read x set ZKEY=$zkey
  ;expect: $ZKEY= 8,0
  use $p write "x= ",x," $zkey= ",ZKEY,!
  write !,"** CLOSE NODESTROY and reOPEN with M:SEEK=""+3""",!
  close p:nodestroy
  open p:(M:seek="+3")
  use p
  read x set ZKEY=$zkey
  ;expect: $ZKEY= 4,0
  use $p write "x= ",x," $zkey= ",ZKEY,!
  write !,"** CLOSE NODESTROY and reOPEN with APPEND:SEEK=""-1""",!
  close p:nodestroy
  open p:(append:seek="-1")
  use p
  read x set ZKEY=$zkey
  ;expect: $ZKEY= 9,0
  use $p write "x= ",x," $zkey= ",ZKEY,!
  close p
  write !,"** CLOSE DESTROY and OPEN non-fixed with SEEK=""120"" and read 60 bytes",!
  open p:seek="120"
  use p
  read x#60 set ZKEY=$zkey
  ;expect: $ZKEY= 180
  use $p write "x= ",x," $zkey= ",ZKEY,!
  write !,"** CLOSE NODESTROY and reOPEN with append:SEEK=""-60"" and read last 60 bytes",!
  close p:nodestroy
  open p:(append:seek="-60")
  use p
  read x#60 set ZKEY=$zkey
  ;expect: $ZKEY= 540
  use $p write "x= ",x," $zkey= ",ZKEY,!
  close p
  quit