'if -e'和'if -f'之间的区别 [英] Difference between 'if -e' and 'if -f'

问题描述

在if条件下有两个用于检查文件的开关:-e和-f.

There are two switches for the if condition which check for a file: -e and -f.

这两者之间有什么区别?

What is the difference between those two?

推荐答案

请参阅:我相信这些不是"if开关"，而是测试开关"(因为您必须在[]括号内使用它们.

I believe those aren't "if switches", rather "test switches" (because you have to use them inside [] brackets.

但是区别是:

[ -e FILE ]如果FILE存在，则为true.

[ -e FILE ] True if FILE exists.

这将为/etc/hosts和/dev/null以及目录返回 true .

This will return true for both /etc/hosts and /dev/null and for directories.

[ -f FILE ]如果FILE存在且为常规文件，则为true. 对于/etc/hosts，这将返回 true ，对于/dev/null，将返回 false (因为它不是常规文件)，对于 false . >，因为它是目录.

[ -f FILE ] True if FILE exists and is a regular file. This will return true for /etc/hosts and false for /dev/null (because it is not a regular file), and false for /dev since it is a directory.

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