如何在fortran的特定行写 [英] How to write at specific lines in fortran

问题描述

我想从一个文件夹复制一个文件并使用fortran在文件的特定行写入。我正在使用Windows，GNU fortran编译器。这里是示例文件和代码。
file1.txt

I want to copy a file from a folder and write at specific lines of the file using fortran. I am using Windows, GNU fortran compiler. Here is sample file and code. file1.txt

1 *
2 **
3 ***
4 ****
5 *****
6 ******
7 *******
8 ********
9 *********
10 **********

这里是代码：
我定义了一些变量。只有两个标准匹配（特别是变量值和行号），我才想写入文件中的新文本。我尝试使用 system 命令进行复制，但失败。任何人都可以告诉我正确的使用方法吗？程序运行时错误格式化呈现为无格式文本

Here is code: I defined some variables. Only if two criteria match (particular variable value and line number), I want to write in the new text in the file. I tried using system command to copy, but it fails. Can anyone tell me correct way of using this? And program got run time error FORMAT present for unformatted text

program read

   integer :: a,b,c,d,e
   CHARACTER (LEN=200) :: str

   a=0
   b=1
   c=0
   d=1
   e=0

    !call system ("copy" // "D:\test1\file1.txt"," ", // "D:")
    !This command fails

   open (unit=10, file="file1.txt", access="direct", & 
form="unformatted",  action="readwrite", recl=100 )

   do i=1,10,1
    read (10,*) str 

    if(a==0 .AND. i==3) then
        write(10,100) 'This is ',i,' line'
    else if(b==0 .AND. i==4) then
        write(10,100) 'This is ',i,' line'
    else if(c==0 .AND. i==5) then
        write(10,100) 'This is ',i,' line'
    else if(d==0 .AND. i==6) then
        write(10,100) 'This is ',i,' line'
    else if(e==0 .AND. i==7) then
        write(10,100) 'This is ',i,' line'
    100 format (2a,i0,1X)
    end if
   end do

   close (unit=10)  
end program 

我可以在同一个文件中读写吗？请分享您的意见。我提到了一些问题： Fortran - How to write数据到文件中的特定行？，但无法帮助我。

Can I read and write in the same file? Please share your comments. I referred to some questions Fortran - How to write data to specific line in the file? but couldn't help me.

推荐答案

与您的系统调用。首先，你需要在 copy 和第一个参数之间有一个空格。其次，你需要一个目标文件，而不仅仅是一个文件夹。另外，您应该只使用字符串连接器 // ，而不是逗号。例如，如果你想复制到一个新的文件名 file2.txt ，你可以使用像这样的系统调用：

There are a couple things wrong with your system call. First, you need a space between copy and the first argument. Second, you need a destination file, not just a folder. Also, you should only be using string concatenaters //, not commas. For example, if you want to copy to a new file name file2.txt, you can use a system call like this:

call system ("copy " // "D:\test1\file1.txt " // "D:\test1\file2.txt")

因为您使用的是文字字符串而不是变量，所以您可以通过删除连接器来简化它： / p>

Because you're using literal strings instead of variables, you can simplify it by getting rid of the concatenaters:

call system ("copy D:\test1\file1.txt D:\test1\file2.txt")

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