On 15 Jan 2015, at 10:56, Maruan Sahyoun <sahy...@fileaffairs.de> wrote: > > so if I understand an summarize correctly we'd change > > - the usage() for all to return 1
Except when the user has asked for the usage via -h, because that’s a success, not a failure. > - print messages on exceptions to System.err > - rethrow the exception so java can handle it if it will terminate afterwards > anyway Yes, I think we mostly do that… if not in all cases, then we should be doing that, at least for IOException. > - use something above 2 and below 126 as an error code for System.exit() if > rethrowing doesn't make sense 1 is fine, as I’d expect you’ll be dealing with exceptions due to invalid passwords, encryption, etc. which are everyday problems. > OK? > > Maruan > > > Am 15.01.2015 um 19:03 schrieb John Hewson <j...@jahewson.com>: > >> If the usage was printed due to invalid command line parameters, then the >> convention on Unix is to return exit code 1. We should be doing that too. >> >> Note than if Java throws an exception which causes main() to exit and there >> is no catch clause, then java will return a non-zero code of its own accord. >> If we’re catching fatal exceptions in main, then we should System.exit(1) >> afterwards. >> >> -- John >> >>> On 15 Jan 2015, at 09:13, Maruan Sahyoun <sahy...@fileaffairs.de> wrote: >>> >>> Yes, >>> >>> current behavior within the tools >>> usage(): some tools have a System.exit, some don't and for the ones they >>> have the exit code is not always the same. >>> -main() there is no System.exit for the ones I looked at in case of an >>> error. Only an error message is written to System.err >>> >>> You'd rather expect System.exit > 0 in case there is an issue in main >>> processing and then System.exit as part of usage makes sense. If there is >>> none on main there shouldn't be one on usage(). >>> >>> So I'd remove it on usage() too. >>> >>> WDYT? >>> >>> Maruan >>> >>> Am 15.01.2015 um 18:00 schrieb Andreas Lehmkuehler <andr...@lehmi.de>: >>> >>>> Hi, >>>> >>>> Am 15.01.2015 um 17:20 schrieb John Hewson: >>>>> Only if there's a non-zero number used as the argument. >>>> Yes, but IMO such a value is only useful if there is any processing issue. >>>> Maruans question targets those calls within the usage message which is >>>> shown only if there is any issue with the given commandline parameters. >>>> >>>> I'd remove such calls. >>>> >>>>> -- John >>>>> >>>>>> On 15 Jan 2015, at 06:06, Maruan Sahyoun <sahy...@fileaffairs.de> wrote: >>>>>> >>>>>> Hi, >>>>>> >>>>>> do we need System.exit() in our command line tools usage messages? >>>>>> Opinions? Don't see a benefit of having them. >>>>>> >>>>>> BR >>>>>> Maruan >>>> >>>> BR >>>> Andreas LEhmkühler >>> >> >
