cargo-watch

Watch and rebuild on changes

$ cargo watch

$ cargo watch -x test

$ cargo watch -x "run --example [example_name]"

$ cargo watch -x check -x test -x run

$ cargo watch -c

$ cargo watch -w [src/] -w [tests/]

$ cargo watch -i "*.txt" -i "target/"

$ cargo watch -s "echo 'Changed!' && cargo build"

cargo watch [options] [-x command]...

cargo-watch is a Cargo subcommand that watches project source files and runs Cargo commands when files change. It provides a convenient development workflow for continuous compilation, testing, or running.
By default, cargo watch runs `cargo check` on changes. Multiple commands can be chained with `-x` flags and will run in sequence. The tool debounces rapid file changes to avoid excessive rebuilds.
It watches all files that Cargo considers part of the project, including src/, tests/, benches/, examples/, and Cargo.toml. Custom watch paths and ignore patterns can be specified.

-x command

Cargo command to run (default: check).

Shell command to run.

Clear screen before each run.

Watch specific path (can repeat).

Ignore files matching pattern.

Debounce delay in seconds.

Use polling instead of events.

Postpone first run until change.

Suppress output from watch itself.

Don't use .gitignore patterns.

Show which file triggered the run.

Run command before watched command.

Send desktop notification on finish.

Requires installation via `cargo install cargo-watch`. File system events may not work in all environments (use --poll as fallback). Rapid consecutive saves may be debounced into single runs. Large projects may benefit from increased debounce delay.

cargo-watch was created by F\u00e9lix Saparelli (passcod) in 2015 to provide file watching functionality for Rust development. It built upon the notify crate for cross-platform file system events. The tool has become a standard part of many Rust developers' workflows, inspired by similar tools in other ecosystems like nodemon for Node.js.

cargo(1), cargo-check(1), watchexec(1), entr(1)