Hi Kirk, On Thu, May 10, 2018 at 8:07 AM, Kirk Pepperdine <kirk.pepperd...@gmail.com> wrote: > >> On May 10, 2018, at 7:04 AM, Thomas Stüfe <thomas.stu...@gmail.com> wrote: >> >> Oh... maybe. You are right. And I see commas are not good either since >> they are used in sub options (e.g. GC.class_stats). >> >> Alternative ideas could be using brackets surrounding the >> command-and-options (e.g. '{''}'): >> >> jcmd { GC.class_stats columns=InstBytes,KlassBytes } { VM.metaspace >> show-loaders } > > are exposed braces safe in shells? >> >> I think technically we would not even need delimiters, since the >> commands are as keywords limiting enough. E.g. one could just specify: >> >> jcmd GC.class_stats columns=InstBytes,KlassBytes VM.metaspace show-loaders > > I’d vote for this form. Simple..
I think so too. Note how it would influence the form of jcmd command files: <command 1> <command 2> would execute two commands sequentially at different safepoints <command 1> <command 2> would execute two commands at the same safepoint Arguably though, if we can stack commands at the command line, the jcmd file gets less important. I'll play around a bit and wait what others say. Thanks, Thomas > > — Kirk > >> >> and that would be for jcmd too. It is more for the benefit of the user. >> >> On Thu, May 10, 2018 at 7:54 AM, Kirk Pepperdine >> <kirk.pepperd...@gmail.com> wrote: >>> Awesome idea! Would the semicolon would be an issue for shell scripts? >>>> On May 10, 2018, at 6:52 AM, Thomas Stüfe <thomas.stu...@gmail.com> wrote: >>>> >>>> Hi all, >>>> >>>> just asking around for opinions. >>>> >>>> I am playing with the idea of bundling diagnostic commands to have >>>> them executed at the same safepoint, in order to get results >>>> consistent with each other. E.g. a heapdump and a corresponding >>>> metaspace statistic. >>>> >>>> Syntax wise, I think one could specify multiple commands in jcmd >>>> separated by comma or semicola: >>>> >>>> jcmd <command> <option> <option>; <command 2> <option> <option> >>>> >>>> What do you think, would that be a useful addition? >>>> >>>> Thanks, Thomas >>> >