[子程序] 连续两次调用子例行程序 出错

Subroutine  NUM_LINE(Num) 
    Integer::Numline=0,value=0,Num
    Character line
    OPEN(UNIT=11,FILE='material.txt',STATUS='OLD')
    Do While(value==0)
    Read(11,*,iostat=value) line
    If(value/=0)cycle
    Numline=Numline+1
    End Do
    Num=Numline
    Close(11)
    End 

Integer Function Num_Line() result( Num )
  Integer   :: k
  Character :: line
  Num = 0 !//这个很重要
  OPEN(11,FILE='material.txt',STATUS='OLD')
  Do
    Read(11,*,iostat=k) line
    If( k /= 0 ) exit
    Num = Num + 1
  End Do
  Close(11)
End Function Num_Line