std::experimental::filesystem::absolute, std::experimental::filesystem::system_complete

Header: <experimental/filesystem>

Returns absolute path of p relative to base according to the following rules: If p has both root name and root directory (e.g. “C:\users”, then the path is returned, unmodified.If p has a root name not followed by a root directory (e.g. “C:text.txt”), then base is inserted between p’s root name and the remainder of p. Formally, p.root_name() / fs::absolute(base).root_directory() / fs::absolute(base).relative_path() / p.relative_path() is returned,If p has no root name, but has a root directory (e.g. “/var/tmp/file.txt” on a POSIX system or “\users\ABC\Document.doc” on Windows, then the root name of base, if it has one, is prepended to p (on a POSIX system, p is not modified, on a Windows system, “\users\ABC\Document.doc” becomes “C:\users\ABC\Document.doc”. Formally, fs::absolute(base).root_name() / p is returned.If p has no root name and no root directory (e.g. “../file.txt”, then the entire base is prepended to p. Formally, absolute(base) / p is returned.

# Declarations

path absolute( const path& p, const path& base = current_path() );

(filesystem TS)

path system_complete( const path& p );
path system_complete( const path& p, error_code& ec );

(filesystem TS)

# Parameters

p: path to convert to absolute form
base: path (not necessarily absolute) to serve as the starting location
ec: out-parameter for error reporting in the non-throwing overload

# Return value

Returns an absolute (although not necessarily canonical) path formed by combining p and base as described above.

# Notes

On systems that support root names (e.g. Windows), the result of calling absolute on a relative path that has a root name (e.g. “D:file.txt” when the root name of base is different will usually result in a non-existent path.

# Example

#include <filesystem>
#include <iostream>
namespace fs = std::experimental::filesystem;
 
int main()
{
    fs::path p = "C:cl.exe";
    std::cout << "Current path is " << fs::current_path() << '\n'
              << "Absolute path for " << p << " is " << fs::absolute(p) << '\n'
	      << "System complete path for " << p << " is "
              << fs::system_complete(p) << '\n';
}

# See also

canonical