Clippy lint · Restriction · checked with Clippy 0.1.99

clippy::create_dir: calling `std::fs::create_dir` where there may be a better way

What it meansChecks usage of std::fs::create_dir and suggest using std::fs::create_dir_all instead. It is in the restriction group and off by default.

What you see

warning: calling `std::fs::create_dir` where there may be a better way
 --> main.rs:3:1
  |
3 | std::fs::create_dir("foo");
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#create_dir
  = note: requested on the command line with `-W clippy::create-dir`
help: consider calling `std::fs::create_dir_all` instead
  |
3 | std::fs::create_dir_all("foo");
  |                    ++++

Real output of Clippy 0.1.99 (Rust 1.99) on the example below. Names and line numbers in yours will differ.

Does it matter?

Sometimes std::fs::create_dir is mistakenly chosen over std::fs::create_dir_all, resulting in failure when more than one directory needs to be created or when the directory already exists. Crates which never need to specifically create a single directory may wish to prevent this mistake.

Lints that forbid language features for specific codebases (no unwrap, no indexing...). Off by default; pick them one by one, never the whole group.

How to fix it

Clippy does not fix this one automatically (its suggestion may change behaviour, so it only shows it). Change the code by hand:

Flagged

std::fs::create_dir("foo");

Write this instead

std::fs::create_dir_all("foo");

Turn it off, or on

It is off by default. To use it, set it to warn or deny:

Whole crate (Cargo.toml)

[lints.clippy]
create_dir = "warn"

In code

#![warn(clippy::create_dir)]

One run

cargo clippy -- -W clippy::create-dir

The [lints] table needs Rust 1.74 or newer. In a workspace, put it under [workspace.lints.clippy] and add [lints] workspace = true to each member.

Restrictiongroup

allowdefault level

nofixed by cargo clippy --fix

1.48.0added in Rust

Clippy's own documentation

What it does

Checks usage of std::fs::create_dir and suggest using std::fs::create_dir_all instead.

Why restrict this?

Sometimes std::fs::create_dir is mistakenly chosen over std::fs::create_dir_all, resulting in failure when more than one directory needs to be created or when the directory already exists. Crates which never need to specifically create a single directory may wish to prevent this mistake.

Example

std::fs::create_dir("foo");

Use instead:

std::fs::create_dir_all("foo");

From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.

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