# fs-err [](https://crates.io/crates/fs-err) [](https://github.com/andrewhickman/fs-err/actions?query=workflow%3ACI) fs-err is a drop-in replacement for [`std::fs`][std::fs] that provides more helpful messages on errors. Extra information includes which operations was attempted and any involved paths. ## Error Messages Using [`std::fs`][std::fs], if this code fails: ```rust let file = File::open("does not exist.txt")?; ``` The error message that Rust gives you isn't very useful: ```txt The system cannot find the file specified. (os error 2) ``` ...but if we use fs-err instead, our error contains more actionable information: ```txt failed to open file `does not exist.txt`: The system cannot find the file specified. (os error 2) ``` ## Usage fs-err's API is the same as [`std::fs`][std::fs], so migrating code to use it is easy. ```rust // use std::fs; use fs_err as fs; let contents = fs::read_to_string("foo.txt")?; println!("Read foo.txt: {}", contents); ``` fs-err uses [`std::io::Error`][std::io::Error] for all errors. This helps fs-err compose well with traits from the standard library like [`std::io::Read`][std::io::Read] and crates that use them like [`serde_json`][serde_json]: ```rust use fs_err::File; let file = File::open("my-config.json")?; // If an I/O error occurs inside serde_json, the error will include a file path // as well as what operation was being performed. let decoded: Vec = serde_json::from_reader(file)?; println!("Program config: {:?}", decoded); ``` ## Feature flags * `expose_original_error`: when enabled, the [`Error::source()`](https://doc.rust-lang.org/stable/std/error/trait.Error.html#method.source) method of errors returned by this crate return the original `io::Error`. To avoid duplication in error messages, this also suppresses printing its message in their `Display` implementation, so make sure that you are printing the full error chain. ## Minimum Supported Rust Version The oldest rust version this crate is tested on is **1.40**. This crate will generally be conservative with rust version updates. It uses the [`autocfg`](https://crates.io/crates/autocfg) crate to allow wrapping new APIs without incrementing the MSRV. If the `tokio` feature is enabled, this crate will inherit the MSRV of the selected [`tokio`](https://crates.io/crates/tokio) version. [std::fs]: https://doc.rust-lang.org/stable/std/fs/ [std::io::Error]: https://doc.rust-lang.org/stable/std/io/struct.Error.html [std::io::Read]: https://doc.rust-lang.org/stable/std/io/trait.Read.html [serde_json]: https://crates.io/crates/serde_json ## License Licensed under either of * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or https://www.apache.org/licenses/LICENSE-2.0) * MIT license ([LICENSE-MIT](LICENSE-MIT) or https://opensource.org/licenses/MIT) at your option. ### Contribution Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.