CODEWITHSUNDEEP
c++linux
budekatude
budekatude

Reputation: 443

Absolute file path in c++ under Linux

I've been trying to access a given file that is always in the same location with the following C++ code:

if (pcl::io::loadPCDFile<pcl::PointXYZ> ("~/Downloads/table_scene_lms400.pcd", *cloud) == -1) //* load the file

Since apparently the "~" is not working under C++, various posts on the internet suggest using /home/Downloads/... instead. I do not however seem to get it to work. I keep getting an error saying that the given file under above path cannot be found.

What is the correct way to access an absolute file path in C++?

Thanks very much, and sorry for the basicness of the question!

Upvotes: 2

Views: 11534

Answers (3)

Galik
Galik

Reputation: 48605

C++ runtime doesn't expand file paths. What I do is something like this:

#include <cstdlib>

std::string const HOME = std::getenv("HOME") ? std::getenv("HOME") : ".";

std::ifstream myfile(HOME + "/path/in/home/folder.txt");

Upvotes: 3

nwp
nwp

Reputation: 9991

Shells such as bash and zsh expand ~ to the home directory. The function you used doesn't. You will have to expand it some other way. You can cd ~ and then pwd to figure out where the shell thinks your home directory is and use that. Alternatively you can launch a shell and ask it for the home directory or try an environment variable or use some library such as Qt: QDir::homePath().

Upvotes: 5

Some programmer dude
Some programmer dude

Reputation: 409166

The tilde ~ is expanded by the shell, it's not a universal part of paths.

I suggest you use the environment variable HOME to get the path to the current users home-directory, and then append the rest of the path.

Upvotes: 2

Related Questions