如何在C ++中打开具有相对路径的文件? [英] How to open a file with relative path in C++?

问题描述

我现在正在编写测试用例，并创建了一些尝试读取的测试文件.绝对路径为:

I am writing test cases right now and I created some test files which I try to read. The absolute path is:

/home/user/code/Project/source/Project/components/Project/test/file.dat

但是出于显而易见的原因，使用绝对路径进行测试是不好的.因此，我尝试将绝对路径转换为相对路径，但我不知道为什么它不起作用.我用相对路径

but testing with an absolute path is bad for obvious reasons. So I try to convert the absolute path into a relative one and I don't know why it doesn't work. I created a file with the relative path

findme.dat

我在

/home/user/code/Project/build/source/Project/components/Project/test/findme.dat

所以我创建了相对路径

/../../../../../../source/Project/components/Project/test/file.dat

，但文件未打开且未与is对象相关联， std::ifstream is (path);，并且is.is_open()函数返回fulse.

but the file is not open and not associated with the is object, std::ifstream is (path);, and the is.is_open() function returns fulse.

你能帮我吗?

推荐答案

您所使用的根本不是相对路径.确定使用的是相对路径语法，而不是实际含义.

What you are using is not at all a relative path. Sure you are using the relative path syntax but not the actual meaning of what it is.

/../../../../../../source/Project/components/Project/test/file.dat

/../../../../../../source/Project/components/Project/test/file.dat

此路径以/开头，表示root，然后找到它的父级，由于root没有父级并继续运行，因此它再次返回root.

This path starts with a / which means root then finds it parent which return root again since root has no parent and goes on... The simplified version of this is:

/source/Project/components/Project/test/file.dat

/source/Project/components/Project/test/file.dat

因此它将在根目录中查找当然不存在的文件夹源.

So it will look for folder source in root which of-course doesn't exist.

您应该做的是这样的(假设您的代码在项目文件夹中):

What you should do is something like this (assuming your code is in project folder):

./test/file.dat

./test/file.dat

，或者如果它位于Project文件夹中的其他文件夹中，则可以执行以下操作:

or if it is in some other folder within Project folder you can do something like this:

../test/file.dat

../test/file.dat

../带您到当前代码目录的父目录，在这种情况下，该目录为Project.

../ take you to the parent of your current code directory which under this case's assumption is Project.

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