代码如下：

program wwlln_shiyan
    implicit none

    !声明变量
    character(len=512)::cRead
    character(len=20)::filename,DYfilename
    character(len=20)::wwlln_date,wwlln_time
    real::lat,lon
    real::timingerror
    integer::station
    integer::status1=0
    integer,parameter::fileid1=12,fileid2=13
    integer::i
    logical alive
    
    !循环读取文件
    OPEN(14,file="filename.txt",status="old")
    OPEN(15,file="DYfilename.txt",status="old")
    do i=20040810,20151130,1
        READ(14,*)filename
        READ(15,*)DYfilename
        inquire(file=filename,exist=alive)
        if (alive) then
    
        !读取数据
            OPEN(11,file=filename,status='old',form='formatted')
            OPEN(13,file=DYfilename,status='replace')
    
            do while(.true.)
                READ(11,"(A512)",iostat=status1)cRead
                if (status1/=0) exit
                CALL parserRead(cRead)
                if((lat>21).AND.(lat<34).AND.(lon>97).AND.(lon<111)) then
                    write(*,*)wwlln_date,wwlln_time,lat,lon,timingerror,station
                    write(13,*)wwlln_date,wwlln_time,lat,lon,timingerror,station
                end if
            end do
            CLOSE(11)
            CLOSE(13)
        else
            CYCLE
        end if
        
    end do
    
    
        CLOSE(11)
        CLOSE(13)
    
        STOP


contains
    !调用子程序
    subroutine parserRead(c)
        character(len=*)::c
        integer::j
        
        do j=1,LEN_TRIM(c)
            if (c(j:j)=="/") c(j:j)="|"
        end do
        READ(c,*)wwlln_date,wwlln_time,lat,lon,timingerror,station
        do j=1,LEN_TRIM(wwlln_date)
            if (wwlln_date(j:j)=="|") wwlln_date(j:j)="/"
        end do
    end subroutine parserRead

    
end program wwlln_shiyan

！生成filename.txt

program wwlln_filename
    implicit none

    !声明变量
    integer::i
    
    OPEN(11,file='filename.txt',status='replace')
    do i=20040810,20151130,1
        write(11,"(1x,A1,I8,A4)")"A",i,".txt"
    end do
    
end program wwlln_filename

!生成DYfilename.txt（即经过经纬度拆选后的数据存放txt）

program wwlln_DYfilename
    implicit none

    !声明变量
    integer::i
    
    OPEN(11,file='DYfilename.txt',status='replace')
    do i=20040810,20151130,1
        write(11,"(1x,I8,A4)")i,".txt"
    end do
    
end program wwlln_DYfilename

最后：计算机配置不够，在运行过大的数据会出现end of file 的报错。