怎么在文件开头写入数据而不覆盖原有内容？

fcode

[Fortran] 纯文本查看 复制代码

program main
  implicit none
  integer :: A(5,3)
  integer :: nsize, irow
  A( 1, : ) = [ 5, 4, 8 ]
  A( 2, : ) = [ 4, 1, 9 ]
  A( 3, : ) = [ 3, 4, 8 ]
  A( 4, : ) = [ 1, 2, 8 ]
  A( 5, : ) = [ 3, 1, 0 ]
  Open(Unit=34, File="TimeLog.txt")
  write(34,100) 0 !//假设暂时不知道大小，先写入一个 0 占位
  Do irow = 1, size(A,1)
    write(34,*) A(irow,:)
  End Do
  Close(34)
  nsize = 5
  Open(Unit=34, File="TimeLog.txt",form="formatted",access="direct",Status="old",recl=9)
  write(34,100,rec=1) nSize
  Close(34)
100 format(i9)
end program main