Execute commands when files are updated

Execute commands automatically when files are updated.

Installation

You will need cargo installed. Make sure you have nightly installed.

rustup update nightly  

Then install using:

cargo install --git https://github.com/nobriot/re-execute.git

The command is shortened to rex

Quick overview

The UI looks like this:

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Usage

You can get started reading the help page: rex -h

By default, any file hidden or gitignored under the directories being watched will not trigger any command execution.

rex [OPTIONS] [COMMAND]...

If the command contains the {file} string, it will be replaced by updated files and one command per updated file will be executed.

If the command contains the {files} string, it will be replaced by a space separated list of files that were updated, and one command in total will be executed.

Examples

Just annouce updated files in your config folder:

rex -f $HOME/.config echo "updated files: {files}"

You will have to escape commands with quotes if they contain tokens interpreted by the shell, e.g. &&:

rex -f ~/Desktop "sleep 6 && echo {file}"

Run plantuml every time a puml file is modified in the current directory:

rex -e puml plantuml {file}

Build your documentation when a .md or .rst file is updated in the docs/ directory Using -e md,rst is also valid. Use -e "" to allow files without extensions.

rex -f docs/ -e md -e rst make docs

Launch some tests when you update test files:

rex -f src/ -e py -r 'test' -- pytest -k {file}

Env variables

Pass additional environment variables using the --env with KEY=VALUE format

rex --env FOO=BAR ./assets/file_and_env.sh {file}

Parameters

A non-exhaustive list of parameters for the program:

• -q / --quiet: Do not print children's stdout/stderr messages
• -e / --extension: Specify extensions to allow. Will ignore other extensions. e.g. -e md -e "" for .md and extension-less files
• -E / --env: Set an env variable for the command, e.g. --env FOO=bar
• -r / --regex: Add a regex to match filenames with. e.g. -r '^[a-z0-9A-Z]*$' will only match filenames with alphanumerical characters. Note that if a file watch in in a/path and the updated file ia a/path/a/file, then the second part will be evaluated against the regex, i.e. a/file
• -R / --ignored_regex: Add a regex that if matches, filenames will be ignored.
• -t / --time: Print the time when each command was executed
• -H / --hidden: Include hidden files in the triggers
• -d / --deleted: Call the commands also with files that have been deleted
• -a / --abort-previous: Abort previous ongoing command execution when files are updated while the program is running
• --force-poll: Use polling to get files update events. May be necessary on some machines.

Related tools

This is just a small program I made for my own fun. If you'd like the more professional tools, look here:

• reflex
• watchexec
• fswatch
• entr
• chokidar
• checkexec
• When-changed