Hi Grant: Why use SIGHUP, Does it has something to do with configure file modification? I don't get it. Thank you.
On Thu, Mar 26, 2015 at 11:49 PM, Grant Edwards <invalid@invalid.invalid> wrote: > On 2015-03-26, Ben Finney <ben+pyt...@benfinney.id.au> wrote: >> Jerry OELoo <oylje...@gmail.com> writes: >> >>> Currently, I can just think out that I put status into a configure >>> file, and service schedule read this file and get status value, >> >> That sounds like a fine start. Some advice: >> >> * You may be tempted to make the configuration file executable (e.g. >> Python code). Resist that temptation; keep it *much* simpler, a >> non-executable data format. >> >> Python's standard library has the ‘configparser’ module >> <URL:https://docs.python.org/3/library/configparser.html> to parse and >> provide the values from a very common configuration file format. >> Use that unless you have a good reason not to. > > I second the recommendation for configparser for stuff of simple to > moderate complexity. If it gets too complex for configparser, you may > want to consider JSON, or for even more complex stuff just use plain > Python code in your config file (this can be very powerful and > expressive, but can also be diffucult to implement safely). > >> * Your program can “poll” the configuration file to see whether it has >> changed. At startup, read the config file's modification timestamp >> <URL:https://docs.python.org/3/library/os.html#os.stat_result.st_mtime>. >> >> Make a part of your event loop (assuming your server runs an event >> loop) that wakes up every N seconds (e.g. every 60 seconds) and >> checkes the file's modification timestamp again; if it's newer, record >> that value for future comparisons, then re-read the file for its >> values. > > That sounds rather Windowsesque. The more-or-less standard way to do > handle the situation on Unix is to reread the config file when you get > a SIGHUP. > > -- > Grant Edwards grant.b.edwards Yow! ONE LIFE TO LIVE for > at ALL MY CHILDREN in ANOTHER > gmail.com WORLD all THE DAYS OF > OUR LIVES. > -- > https://mail.python.org/mailman/listinfo/python-list -- Rejoice,I Desire! -- https://mail.python.org/mailman/listinfo/python-list