在Linux中使用RealPath将相对路径更改为C ++中的绝对路径

Question

I need to change a relative path to absolute path in linux in C++. I am using realpath, but the output is wrong!

char resolved_path[200];
realpath("$HOME/Desktop/SumoSVN/bin", resolved_path);
cout << resolved_path << endl;

I am expecting to get this output : /home/mani/Desktop/SumoSVN/bin

but I am getting this!: /home/mani/Desktop/VENTOS/$HOME

what am I doing wrong?

Answer 1

Shell or environment variables (see environ(7) ) are not expanded by realpath(3) . You need to call getenv(3) . You could try

std::string homedir(getenv("HOME"));
realpath((homedir+"/Desktop/SumoSVN/bin").c_str(), resolved_path);

See also wordexp(3) (and perhaps glob(3) ). Read path_resolution(7) & glob(7) . Notice that it is your shell which expands arguments of commands.

BTW, the current directory is obtained by getcwd(3) .

PS. On some installations with different languages Desktop does not exist: it becomes eg Bureau on French Debian or Ubuntu or Mint systems.