std::filesystem::relative, std::filesystem::proximate
From cppreference.com
< cpp | filesystem
Defined in header <filesystem>
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path relative(
const
std::filesystem::path
& p,
std::error_code & ec ) ; |
(1) | (since C++17) |
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path relative(
const
std::filesystem::path
& p,
const std::filesystem::path & base = std::filesystem::current_path ( ) ) ; |
(2) | (since C++17) |
|
path relative(
const
std::filesystem::path
& p,
const std::filesystem::path& base, |
(3) | (since C++17) |
|
path proximate(
const
std::filesystem::path
& p,
std::error_code & ec ) ; |
(4) | (since C++17) |
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path proximate(
const
std::filesystem::path
& p,
const std::filesystem::path & base = std::filesystem::current_path ( ) ) ; |
(5) | (since C++17) |
|
path proximate(
const
std::filesystem::path
& p,
const std::filesystem::path& base, |
(6) | (since C++17) |
1) Returns relative(p, current_path(), ec)
2,3) Returns p made relative to base. Resolves symlinks and normalizes both p and base before other processing. Effectively returns
std::filesystem::weakly_canonical
(p).lexically_relative
(
std::filesystem::weakly_canonical
(base)
)
or
std::filesystem::weakly_canonical
(p, ec).lexically_relative
(
std::filesystem::weakly_canonical
(base, ec)
)
, except the error code form returns path()
4) Returns proximate(p, current_path(), ec)
5,6) Effectively returns
std::filesystem::weakly_canonical
(p).lexically_proximate
(
std::filesystem::weakly_canonical
(base)
)
or
std::filesystem::weakly_canonical
(p, ec).lexically_proximate
(
std::filesystem::weakly_canonical
(base, ec)
)
, except the error code form returns path()
Parameters
| p | - | an existing path |
| base | - | base path, against which p will be made relative/proximate |
| ec | - | error code to store error status to |
Return value
1)
p made relative against current_path()
2,3) p made relative against base.
4)
p made proximate against current_path()
5,6) p made proximate against base.
Exceptions
Any overload not marked noexcept may throw std::bad_alloc if memory allocation fails.
2,5) Throws std::filesystem::filesystem_error on underlying OS API errors, constructed with p as the first path argument, base
1,3,4,6) Sets a
std::error_code&
parameter to the OS API error code if an OS API call fails, and executes
ec.
clear
()
Example
Run this code
#include <filesystem> #include <iostream> void show(std::filesystem::path x, std::filesystem::path y) { std::cout << "x:\t\t " << x << "\ny:\t\t " << y << '\n' << "relative(x, y): " << std::filesystem::relative(x, y) << '\n' << "proximate(x, y): " << std::filesystem::proximate(x, y) << "\n\n"; } int main() { show("/a/b/c", "/a/b"); show("/a/c", "/a/b"); show("c", "/a/b"); show("/a/b", "c"); }
Possible output:
x: "/a/b/c" y: "/a/b" relative(x, y): "c" proximate(x, y): "c" x: "/a/c" y: "/a/b" relative(x, y): "../c" proximate(x, y): "../c" x: "c" y: "/a/b" relative(x, y): "" proximate(x, y): "c" x: "/a/b" y: "c" relative(x, y): "" proximate(x, y): "/a/b"
See also
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(C++17)
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represents a path (class) |
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(C++17)
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composes an absolute path (function) |
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(C++17)
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composes a canonical path (function) |
| converts path to normal form converts path to relative form converts path to proximate form (public member function of std::filesystem::path) |