如何使用与相同文件运行的命令更新文件?

As an easy example, consider the following command:

作为一个简单的例子，考虑以下命令:

$ sort file.txt

This will output the file's data in sorted order. How do I put that data right back into the same file? I want to update the file with the sorted results.

这将按顺序输出文件的数据。如何将这些数据返回到同一个文件中呢?我想用排序后的结果更新文件。

This is not the solution:

这不是解决办法:

$ sort file.txt > file.txt

... as it will cause the file to come out blank. Is there a way to update this file without creating a temporary file?

…因为它会导致文件为空。有没有一种方法可以在不创建临时文件的情况下更新这个文件?

Sure, I could do something like this:

当然，我可以这样做:

sort file.txt > temp.txt; mv temp.txt file.txt

But I would rather keep the results in memory until processing is done, and then write them back to the same file. sort actually has a flag that will allow this to be possible:

但我宁愿将结果保存在内存中，直到处理完成，然后将它们写回相同的文件。sort实际上有一个标记，可以让它成为可能:

sort file.txt -o file.txt

...but I'm looking for a solution that doesn't rely on the binary having a special flag to account for this, as not all are guaranteed to. Is there some kind of linux command that will hold the data until the processing is finished?

…但我正在寻找一种解决方案，它不依赖于二进制文件有一个特殊的标志来说明这一点，因为并不是所有的二进制文件都保证这样做。是否有某种linux命令可以保存数据直到处理完成?

3 个解决方案

#1

For sort, you can use the -o option.

对于排序，可以使用-o选项。

For a more general solution, you can use sponge, from the moreutils package:

对于更一般的解决方案，你可以使用海绵，从moreutils包装:

sort file.txt | sponge file.txt

As mentioned below, error handling here is tricky. You may end up with an empty file if something goes wrong in the steps before sponge.

正如下面提到的，这里的错误处理很棘手。如果在使用海绵之前的步骤中出现问题，您可能会得到一个空文件。

This is a duplicate of this question, which discusses the solutions above: How do I execute any command editing its file (argument) "in place" using bash?

这是这个问题的副本，它讨论了上面的解决方案:如何执行任何命令编辑它的文件(参数)“到位”使用bash ?

3 个解决方案

#1

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