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std::experi...::equivalent(3)  C++ Standard Libary std::experi...::equivalent(3)

NAME
     std::experimental::filesystem::equivalent	 -   std::experimental::filesys-
     tem::equivalent

Synopsis
	Defined in header <experimental/filesystem>
	bool equivalent( const path& p1, const path& p2 );
	bool equivalent( const path& p1, const path&  p2,  error_code&	ec   (1)
     (filesystem TS)
	);

	Checks	whether  the paths p1 and p2 refer to the same file or directory
     and have the
	same file status as determined by status (symlinks are followed).

	If p1 or p2 does not exist or if their file type is not file, directory,
     or symlink
	(as determined by is_other), an error is reported.

	The non-throwing overload returns false on errors.

Parameters
	p1, p2 - paths to check for equivalence
	ec     - out-parameter for error reporting in the non-throwing overload

Return value
	true if the p1 and p2 refer to the same file or directory and their file
     status is
	the same. false otherwise.

Exceptions
	The overload that does not take an error_code& parameter throws filesys-
     tem_error on
	underlying OS API errors, constructed with p1 as the first argument,  p2
     as the
	second	argument,  and	the  OS  error	code as the error code argument.
     std::bad_alloc
	may be thrown if memory allocation fails. The  overload  taking  an  er-
     ror_code&
	parameter  sets it to the OS API error code if an OS API call fails, and
     executes
	ec.clear() if no errors occur. This overload has
	noexcept specification:
	noexcept

Notes
	Two paths are considered to resolve to the same file  system  entity  if
     st_dev and
	st_ino	of their POSIX stat structure, obtained as if by POSIX stat, are
     equal
	(meaning, the files are located on the same device  at	the  same  loca-
     tion).

	In particular, all hard links for the same file or directory are equiva-
     lent, and a
	symlink and its target on the same file system are equivalent.

Example
     // Run this code

      #include <cstdint>
      #include <experimental/filesystem>
      #include <iostream>
      namespace fs = std::experimental::filesystem;

      int main()
      {
	  // hard link equivalency
	  fs::path p1 = ".";
	  fs::path p2 = fs::current_path();
	  if (fs::equivalent(p1, p2))
	      std::cout << p1 << " is equivalent to " << p2 << '\n';

	  // symlink equivalency
	  fs::path p3 = "/lib/libc.so.6";
	  fs::path p4 = p3.parent_path() / fs::read_symlink(p3);
	  if (fs::equivalent(p3, p4))
	      std::cout << p3 << " is equivalent to " << p4 << '\n';
      }

Possible output:
      "." is equivalent to "/var/tmp/test"
      "/lib/libc.so.6" is equivalent to "/lib/libc-2.12.so"

See also
	status	       determines file attributes
	symlink_status determines file attributes, checking the symlink target
		       (function)

Categories:
	  * Noindexed pages
	  * unconditionally noexcept

Hidden categories:
	  * Pages with unreviewed unconditional noexcept template
	  * Pages with unreviewed noexcept template

http://cppreference.com 	   2024.06.10	   std::experi...::equivalent(3)
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