WatchIt

A program that runs a command when it detects file changes.

Only runs on Linux for now.

Why?

• Restart dev server when source files change
• Re-generate asset based on changes in other assets
• Run a linter / formatter when source file changes

As a fully static binary watchit can easily be deployed anywhere.

Example

watchit react -- echo {}

Installation

With Go available:

go install github.com/rafael-luigi-bekkema/watchit@latest

Or to go install from a clone:

make install

Usage

Run the command when a file changes.

Usage:
  watchit react CMD [flags]

Aliases:
  react, r

Flags:
  -e, --events strings         Filesystem events to watch, comma separated. Options are: create,write,remove,rename,chmod.
  -g, --glob stringArray       Filename patterns to filter to (supports ** and {opt1,opt2}).
  -h, --help                   help for react
  -i, --ignore stringArray     Filename patterns to ignore (see --glob).
  -n, --no-watch stringArray   Patterns for directories that should not be watched. --glob and --ignore do not affect watched directories.
  -p, --path string            Set working directory.
      --placeholder string     String to use as placeholder. If the placeholder appears in the command, it will be replaced with the filename associated with the triggering event. (default "{}")
  -s, --shell string           Shell to use for command. Default is to run the command directly.
  -v, --verbose                Output more information.

Usage:
  watchit generate CMD [flags]

Usage:
  watchit service CMD [flags]

Environment variables

WATCHIT_NO_WATCH can be used to set patterns for directories that should not be watched.
For example add to your .bashrc / .zshrc:

export WATCHIT_NO_WATCH=**/.git:**/node_modules:**/vendor

You can use something like direnv to manage this on a per project basis.

Glob

For glob pattern rules see: https://github.com/bmatcuk/doublestar#patterns

Modes

There are 3 modes: react, generate and service. The mode is the first argument.

react

Runs the command when a file changes.

generate

Runs the command upon start and when a file changes.

service

Runs the command upon start and restarts the command after each burst (within 1 ms) of file changes.

Shell

Normally the command runs directly without a shell. So the first argument is the main command, and further arguments as passed as arguments to the command.
To use things like && or > you can pass a shell, which will then be used to run the command. For example:

watchit react -s $SHELL -- 'echo {} changed && date'
# or
watchit react -s bash -- 'echo {} changed && date'