 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Java Forum / General / December 2007Is it possible to determine if a Java application was invoked from command-line?
As the title asks I am wondering if I can determine if my application has been invoked from the commandline. Alternatively, how might I test if the machine I am running on has graphical capabilities? Thanks Lionel. > As the title asks I am wondering if I can determine if my application > has been invoked from the commandline. Why? > Alternatively, how might I test if the machine I am running on has > graphical capabilities? <http://java.sun.com/javase/6/docs/api/java/awt/ GraphicsEnvironment.html#isHeadless()> -- Andrew T. PhySci.org >> As the title asks I am wondering if I can determine if my application >> has been invoked from the commandline. > > Why? Because. >> Alternatively, how might I test if the machine I am running on has >> graphical capabilities? > > <http://java.sun.com/javase/6/docs/api/java/awt/ > GraphicsEnvironment.html#isHeadless()> Thanks. Now I know what headless means :). It all makes sense now! Lionel. >>> As the title asks I am wondering if I can determine if my application >>> has been invoked from the commandline. >> >> Why? > > Because. No, really, Lionel, why? How can you expect help when you are rude about answering questions yourself?  SignatureLew >>>> As the title asks I am wondering if I can determine if my application >>>> has been invoked from the commandline. [quoted text clipped - 7 lines] > How can you expect help when you are rude about answering questions > yourself? I wasn't intending to be rude, it was tongue in cheek. The reason for me wanting to do it was irrelevant. Perhaps I should have added one of these: :) >>>>> As the title asks I am wondering if I can determine if my application >>>>> has been invoked from the commandline. ... >> How can you expect help when you are rude about answering questions >> yourself? > >I wasn't intending to be rude, it was tongue in cheek. The reason for me >wanting to do it was irrelevant. Perhaps not to a help-desk (though they might be able to provide a better answer, cheaper, knowing the ultimate goal - as opposed to the strategy the questioner thinks might achieve the goal), but this is a discussion forum, so it is every bit as relevant and open for discussion as the original question. OTOH, should you choose the 'help-desk' in future, don't forget.. >..Perhaps I should have added one of these: :) ..lots of these: $ SignatureAndrew Thompson http://www.physci.org/ >>> How can you expect help when you are rude about answering questions >>> yourself? [quoted text clipped - 8 lines] > discussion as the original question. OTOH, should > you choose the 'help-desk' in future, don't forget.. Well, normally I do add a "I'm trying to achieve foo", but this really was a straight forward question and I was trying to spare the reader/helper from excess un-needed information. To the point and concise so as to not waste time. Now that we got this far I may as well say why :). A small app that I'm writing is to run on a server. It can either be a double-clicked jar, or it can be invoked from the command-line. Providing the argument "-noui" on the command-line forces user interaction via the prompt. In graphical mode there is a single dialog with fields and buttons. Since many servers may not run a graphical server I wanted to make sure that in such cases I handle the problem correctly. In such cases the user obviously won't be double clicking the jar file, so a quick check of isHeadless() will allow me to force the command-line user-interaction as though the argument "-noui" was provided. >> ..Perhaps I should have added one of these: :) > > .lots of these: $ lol, I'll give you 0% of those and 200% of these :):). > Now that we got this far I may as well say why :). A small app that > I'm writing is to run on a server. It can either be a double-clicked > jar, or it can be invoked from the command-line. Providing the > argument "-noui" on the command-line forces user interaction via the > prompt. In graphical mode there is a single dialog with fields and > buttons. :):). Well, if that is the case, you may try System.console(). As far as I have tested, it returns a non null object only when started from the console (with java.exe) and null for other invocations. (Sorry if this was mentioned previously, but I can't reread the history of this thread) Piet. > Well, if that is the case, you may try System.console(). As far as I have > tested, it returns a non null object only when started from the console > (with java.exe) and null for other invocations. Since this is a new Java 6 feature, this might not be available to everyone. Henk >> Perhaps not to a help-desk (though they might be able to provide a >> better answer, cheaper, knowing the ultimate goal - as opposed to the [quoted text clipped - 8 lines] > reader/helper from excess un-needed information. To the point and > concise so as to not waste time. One reason for stating your goal is that people like me are often interested in solutions to such goals. I'd probably not be able to benefit so much from the proferred solutions if the goal is hidden. For me it is a question of recognising a similar situation when faced with it and recalling prior discussion here (or being able to find it using a Google Groups search). Which I suppose is just repeating that most of us treat this as a discussion group for the benefit of all, rather than a help desk for only the benefit of the OPs individually. > Which I suppose is just repeating that most of us treat this as a > discussion group for the benefit of all, rather than a help desk for > only the benefit of the OPs individually. I assure you, I do occasionally make a point of reading through unanswered messages to try to help others. But very often there is someone else with a better answer so I restrict my answers to cases in which I know very well. >> Which I suppose is just repeating that most of us treat this as a >> discussion group for the benefit of all, rather than a help desk for [quoted text clipped - 4 lines] > someone else with a better answer so I restrict my answers to cases in > which I know very well. RGB's point was about answering questions about *your* problem, not helping others with theirs. SignatureLew ... (snip tech. answer to 'problem spec.') Thanks for the technical clarification. I suspected it was something along those lines, but it is interesting to have that confirmed. >>> ..Perhaps I should have added one of these: :) >> >> .lots of these: $ > >lol, I'll give you 0% of those and 200% of these :):). .. I think we've reached understanding. ;-) SignatureAndrew Thompson http://www.physci.org/ > Now that we got this far I may as well say why :). A small app that I'm > writing is to run on a server. It can either be a double-clicked jar, or > it can be invoked from the command-line. Providing the argument "-noui" > on the command-line forces user interaction via the prompt. In graphical > mode there is a single dialog with fields and buttons. You may be able to spiff it up a bit past the simple Q&A prompt dialogue. Take a look at the Jcurses package. Its on Sourceforge. I haven't used it, but I did look at its documentation. It seems to be designed to let a Java application present a curses-type screen interface when a graphical interface, e.g. Xterm, isn't available. I didn't do more than read its docs and save a reference to it because it wouldn't do what I needed, which was to bang a cursor round in a 24 x 80 JPanel so I could emulate a terminal as part of a Swing graphical display. I don't have guaranteed a solution to autodetecting a graphical environment, but would reading the terminal type using System.getenv("TERM") tell you anything useful? Signaturemartin@ | Martin Gregorie gregorie. | Essex, UK org | >As the title asks I am wondering if I can determine if my application >has been invoked from the commandline. Possible the behavior of java.lang.System.in.available() might differ. When a console is available, this seems to be a number larger than -1. Without a console, the behavior might differ. It seems as if an exception is raised sometimes. However, I had trouble finding the details, but possibly you can find them yourself. >Alternatively, how might I test if the machine I am running on has >graphical capabilities? see http://mindprod.com/jgloss/headless.html SignatureRoedy Green Canadian Mind Products The Java Glossary http://mindprod.com >> Alternatively, how might I test if the machine I am running on has >> graphical capabilities? > > see http://mindprod.com/jgloss/headless.html Better late than never. We came to this conclusion anyway, but I'm only responding because the wording/grammar on your link could be improved/fixed a bit: "When Java is implemented on a very small device mouse or AWT graphics support may not be available." You might want a comma between device and mouse, or even restructure the sentence completely. At first I read it as java being implemented on a small device OR java being implemented on a mouse OR java being implemented on AWT graphics support - huh. I had to read twice more. "You code cane determine if keyboard, mouse and screen are availble with:" I probably don't need to say anything about the above but I will: "You" should be "Your" "cane" should be "can" "availble' should be "available". Hope this helps. Lionel. Free MagazinesGet these publications absolutely FREE for up to 12 months. There are no hidden fees and no obligation. Simply choose a title, complete the application form and submit it. Read more ...
|
Reply to this Message
|
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2009 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.