watch for filesystem

Watch for file changes and execute Nu code when they happen.


> watch {flags} (path) (closure)


  • --debounce-ms, -d {int}: Debounce changes for this many milliseconds (default: 100). Adjust if you find that single writes are reported as multiple events
  • --glob, -g {string}: Only report changes for files that match this glob pattern (default: all files)
  • --recursive, -r {bool}: Watch all directories under <path> recursively. Will be ignored if <path> is a file (default: true)
  • --quiet, -q: Hide the initial status message (default: false)
  • --verbose, -v: Operate in verbose mode (default: false)


  • path: The path to watch. Can be a file or directory.
  • closure: Some Nu code to run whenever a file changes. The closure will be passed operation, path, and new_path (for renames only) arguments in that order.

Input/output types:



Run cargo test whenever a Rust file changes

> watch . --glob=**/*.rs {|| cargo test }

Watch all changes in the current directory

> watch . { |op, path, new_path| $"($op) ($path) ($new_path)"}

Log all changes in a directory

> watch /foo/bar { |op, path| $"($op) - ($path)(char nl)" | save --append changes_in_bar.log }

Note: if you are looking to run a command every N units of time, this can be accomplished with a loop and sleep

> loop { command; sleep duration }