# [`std::runtime::fs`](/silk/docs/std/runtime-fs/)

Source: [`std/runtime/fs.slk`](https://github.com/oro-computer/silk/blob/master/std/runtime/fs.slk)

This is the exact canonical documentation page for [`std::runtime::fs`](/silk/docs/std/runtime-fs/).

## Role

[`std::runtime::fs`](/silk/docs/std/runtime-fs/) is an implementation-facing runtime module in the shipped [`std/**`](https://github.com/oro-computer/silk/tree/master/std/**) tree.
It exists so higher-level stdlib surfaces can delegate platform or runtime-specific behavior without changing their public module names.

## Canonical Context

Use the following owning docs for the substantive API/design context for this module:

- [runtime](/silk/docs/std/runtime/)
- [fs](/silk/docs/std/fs/)

## Notes

- The shipped source for this module is [`std/runtime/fs.slk`](https://github.com/oro-computer/silk/blob/master/std/runtime/fs.slk).
- The canonical module name is [`std::runtime::fs`](/silk/docs/std/runtime-fs/).
- This module now carries the implementation-facing raw metadata surface used
 by [`std::fs::Stats`](/silk/docs/std/fs/) (`StatInfo`, `StatResult`, `stat`, `lstat`, `fstat`),
 plus `fstat_size` for allocation-free descriptor size probes.
- It also carries the borrowed directory-entry bridge used by
 [`std::fs::Dir.next_view()`](/silk/docs/std/fs/) (`DirEntryBorrowed`,
 `DirEntryBorrowedResult`, `readdir_borrowed`, and
 `readdir_borrowed_into`).
- The hosted implementation exposes raw `chmod` and advisory `flock`/unlock
 operations for the typed [`std::fs`](/silk/docs/std/fs/) wrappers. Unsupported runtimes return the
 stable filesystem `Unsupported` code rather than exposing a platform errno.
- The wrapper's internal errno mapping is defined for every compilation target.
 macOS selects its platform values where they differ; WASI stubs use the
 Linux-shaped `ENOTSUP` value they store in their runtime errno cell, so merely
 importing the portable filesystem graph never depends on a hosted-only
 declaration.
- This page is intentionally implementation-oriented. Downstream users should usually start with the higher-level std module docs listed above unless they are working on the runtime layer itself.