Writing multiple output files in Fortran

Question

Dear All, I am writing a code that writes the out put in multiple files named as 1.dat, 2.dat, ..... Here is my code but it gives some unusual output. May you tell me what i

Answer 1

In my case, I want the file name have an prefix likedyn_

program manyfiles
implicit none
character(len=70) :: filename
integer, parameter :: numfiles=40
integer, parameter :: outunit=44

integer :: filenum, j

do filenum=1,numfiles
    write(filename,'("dyn_",i0,".dat")') filenum
    open(unit=outunit,file=filename, form='formatted')
    write(outunit, *) filenum
    close(outunit)
enddo
end program manyfiles