program search_rand_binary
!------------------------------------------------------------------------------
!Program: Random Binary File Search
!Author: Chris Harper
!Date: 4/8/2008
!------------------------------------------------------------------------------

implicit none

integer :: search, a, i, EOF
character(1) :: c
i = 2 !record 1 is the size of file

!open an unformatted direct access file with 4 bytes per record
open (unit = 10, file = "randombi.dat", status = "old", form = "unformatted", & 
  access = "direct", recl = 4)

print *, "Enter a number to search for:"
read *, search

do
	!read record i
	read (10, rec = i, iostat = EOF) a
	
	if (EOF < 0) then
		!if EOF, exit loop
		print *, search, " not found!"
		exit
	else if (EOF > 0) then
		!if error, print a message and exit
		print *, "File read error occured. Error Number: ", EOF
		exit
	endif
	
	if (a == search) then
		!print record pos
		print *, a, " found at pos ", i
		!continue?
		print *, "Continue searching? (y, n)"
		read *, c
		if (c <> "y") exit
	end if
	
	i = i + 1
end do

close (10)
end program