resurgence

Restart a process when files are changed

inspiration

File watchers are standard in many development workflows, but most utilities only handle execution of short-running processes (compilation, transpilation, formatting, linting). But what if the process runs infinitely?

When developing with PyQt for derivat and the curses for bible, I wanted to see how code changes would affect the graphical / terminal interface. I couldn't use standard file watchers, because they either

would become unresponsive on first execution (application startup), never returning to to event loop and respond
couldn't kill the previous process and thus would continuously spawn another application instance.

resurgence is a product of this need - kill the previous process, if still running, and execute the specified command again, using the updated application source.

requirements

python 2.6+
psutil

installation

$ pip install https://www.github.com/rwev/resurgence/archive/master.zip

usage

$ resurgence --help
resurgence.py [options]
Options:
  -h, --help            show this help message and exit
  -w, --cwd             Observe the current working directory
  -t REGEX_FILE_PATTERNS_TO_OBSERVE, --extensions=REGEX_FILE_PATTERNS_TO_OBSERVE
                        Comma-separated, spaceless list of file patterns to be
                        observed
  -d ADDITIONAL_SUBDIRECTORIES_TO_OBSERVE, --dirs=ADDITIONAL_SUBDIRECTORIES_TO_OBSERVE
                        Comma-separated, spaceless list of subdirectories
                        (below the working directory) to be observed
  -x COMMAND_TO_RUN_STR, --command=COMMAND_TO_RUN_STR
                        Command to run, restart on detected file changes, in
                        single quotes
  -i FILE_CHECK_INTERVAL_SECONDS, --interval=FILE_CHECK_INTERVAL_SECONDS
                        Interval in seconds between checks for file changes.

alternatives

when-changed, also a Python utility, 3rd party dependency watchdog, can't restart processes
entr, C utility, offers -r option to restart process, usable in Unix pipes