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 >
