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std::experi...::equivalent(3) C++ Standard Libarystd::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	direc-
       tory 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,	direc-
       tory, 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 over-
       load

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	a error_code& parameter	throws
       filesystem_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 a 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 locate on the same device at	the same loca-
       tion)

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

Example
       // Run this code

	#include <iostream>
	#include <cstdint>
	#include <experimental/filesystem>
	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 tar-
       get
			 (function)

http://cppreference.com		  2022.07.31	 std::experi...::equivalent(3)

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