std::experi...::equivalent(3)

🦋 std::experimental::filesystem::equivalent 🦋

okay so this page lives in the C++ Standard Libary manual, and its page id is std::experi...::equivalent(3) — yes, the title is abbreviated like that, iykyk 💅

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🌸 NAME 🌸

std::experimental::filesystem::equivalent — the same name, doing its little NAME-section echo. We love a consistent queen 👑✨

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✨ Synopsis ✨

the exact synopsis is giving “line breaks are a suggestion,” but here it is verbatim bestie:

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)
);

okay so this 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. periodt 💀

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🎀 Parameters 🎀

• p1, p2 — paths to check for equivalence, bestie. that’s the whole vibe check 🔍
• ec — out-parameter for error reporting in the non-throwing overload. it catches the tea so the function doesn’t throw ☕🙈

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💖 Return value 💖

returns true if p1 and p2 refer to the same file or directory and their file status is the same. returns false otherwise. literally that simple, no cap 🌟

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🔥 Exceptions 🔥

• the overload that does not take an 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. memory said “not today” 💀
• the overload taking an error_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 ✨

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🧚 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 location 🔗

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. iconic behavior honestly 🌈

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🍓 Example 🍓

run this code, bestie:

// 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';
}

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🌟 Possible output 🌟

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

slay, the paths understood the assignment 💅✨

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👀 See also 👀

• status — determines file attributes
• symlink_status — determines file attributes, checking the symlink target (function)

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💜 Categories 💜

• Noindexed pages
• unconditionally noexcept

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🙈 Hidden categories 🙈

• Pages with unreviewed unconditional noexcept template
• Pages with unreviewed noexcept template

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source/version: http://cppreference.com · date: 2024.06.10 · page id: std::experi...::equivalent(3) — that’s the cute sign-off, bestie 💖🎀🫶