is the following command working under Unix&Linux?
ProcessBuilder prcbdoc = new ProcessBuilder("cmd","/C","start", "Documentation.doc");
prcbdoc.directory(new File(currentDir+"/docs/"));
prcbdoc.start();
I'm not sure because of the "cmd" "/c"
€:
What would be an Linux CentOS equivalent command?
No, it doesn't work. From Java documentation:
a command, a list of strings which signifies the external program file to be invoked and its arguments, if any. Which string lists represent a valid operating system command is system-dependent. For example, it is common for each conceptual argument to be an element in this list, but there are operating systems where programs are expected to tokenize command line strings themselves - on such a system a Java implementation might require commands to contain exactly two elements.
To open a document in a portable manner using AWT:
if (Desktop.isDesktopSupported())
Desktop.getDesktop().open(documentPath);
No, this would not work on Linux (or any other Unix, or on the Mac) due to the "cmd /c" and the "start". On the Mac, you'd say "open Documentation.doc".The various Linux desktops have their own versions of the start/open command: gnome-open for the Gnome desktop, and the FreeDesktop semi-standard xdg-open are some possibilities.
No. cmd and /c are relevant only for windows.
Related
I have a bash script that bootstraps a Java process. I want it to be able to run on *nix and Cygwin. The problem is the separator in the -classpath parameter is different under the two platforms (: under *nix and ; under Windows).
I can't find an environment variable that specifies this separator (same as $PATH separator), so is there a better way to solve this than detecting the OS and hard-coding?
No. If you write your bootstrap code in Java rather than Bash, you can use the path.separator system property.
Otherwise, it's quite normal to see separate launcher scripts for both Unix and Windows.
I'd like to know what the best alternative is for running command line executables from Java. The Target platforms for the commands are Windows 7(+) and Unix/Linux.
I have a class that currently uses Runtime.exec() along with the enhancements from the JavaWorld StreamGobbler article. It works about 90% of the time on both Windows and Unix. The other 10% of the time I need to extend the class and then fiddle with putting cmd.exe of /bin/sh in front of the command. I've also had to fiddle sometimes between using a single String that has command and arguments to splitting the command and args into a String[] array.
My latest is a new error/exception "java.lang.IllegalArgumentException: Executable name has embedded quote, split the arguments." My current Runtime.exec() class works fine in Eclipse running as a Java application, but once I build it and run from an actually command prompt, it fails with the above exception.
So now I'm reading that we should be using ProcessBuilder to do command line executables to the OS platform.
My question is, what is the best alternative? Runtime.exec(), ProcessBuilder, or some other option? Is there one option that will service both Windows and Unix/Linux? If not, which one works best with Windows? Which one works best with Unix/Linux?
tia, adym
Not sure how to give Bohemian credit, but I used ProcessBuilder...Solution is at :
Java - ProcessBuilder command arguments with spaces and double-quotes fails
When I execute a command using ProcessBuilder, how does it know where to look for that command? Using this hack/trick I've modified my PATH variable (verified by inspecting processBuilder.environment()) to be bad (empty, working dir, etc) but ProcessBuilder can still execute sort, echo, bash, etc. just fine. How is it doing this?!
Note: My particular development environment is OSX but this code will also run on Red Hat Enterprise Linux.
The documentation says
[...] a command, a list of strings which signifies the external program file to be invoked and its arguments, if any. Which string lists represent a valid operating system command is system-dependent. [...]
Which in essence mean that where it looks for programs to execute depends on the particular system and JVM you're running on.
I can't find a complete matrix of JVM / System behaviors, but supposedly it behaves similar to the popular shells of the system (bash for *nix and cmd for windows) i.e. it searches the directories in the PATH environment variable from left to right and executes the first executable file it finds.
If you want to take control of finding commands, then, well, take control of finding commands. Don't let ProcessBuilder search. Use your own code to find what you want to run, and then put an absolute pathname into the parameter to ProcessBuilder.
I'm using a bat file to run my jar. The code in my bat file is this :
#echo off
java -cp analyser.jar be.model.Start
pause
This works fine for windows.
But it doesn't do anything at linux. I also need to be sure it will run on Mac
Bat files are specific to Windows. You would need to execute the command in Linux and Mac in a manner that is specific to those platforms. The actual java call should work the same, I believe. The one change to the java line would be if you had multiple items in the classpath. In that case, you would need to use a colon as a separator instead of a semicolon (which is what Windows uses). (Thanks to khachik for that tip)
For Linux, you would use Shell programming using a BASH script. Here is a link that will describe what you need to do:
http://www.tldp.org/HOWTO/Bash-Prog-Intro-HOWTO.html
For Mac, you would probably use an AppleScript. Here is an article on how to get started with AppleScripts:
http://www.macosxautomation.com/applescript/firsttutorial/index.html
For Linux, why not use a .sh (shell) file?
As Biggs~ alreay said, the actual Java call should remain the same.
Update:
You will also have to make it executable by changing it's user permissions. To do this, use: chmod +x thescript.sh
I need to call Cygwin from Java code ( example : to call make command in Cygwin from Java app which run on linux and windows ).Does anybody have experience with this problem ?
I think you have to differentiate youre code for linux and windows
on linux simply execute the command
on windows lauch your command in cygwin with
C:\cygwin\bin\bash.exe --login -i -c <cmd>
note: you may use apache commons exec to lauch an external command from java
Use ProcessBuilder from Java:
http://download.oracle.com/javase/7/docs/api/java/lang/ProcessBuilder.html
You will need to make sure your path/environment is set up properly, but that depends on your machine and set up.
Also, note that many cygwin "capabilities" (e.g., less, awk, sed, etc) are simply binaries (executables) that you can call directly -- no need for the bash shell to facilitate access to those. Look at the actual files in wherever your bin folder is (usually c:/cygwin/bin) and try calling those directly from ProcessBuilder. If you need to actually leverage the shell (e.g., pipes, variables, globbing, etc) then that's a different story -- you would then integrate with the bash.exe file itself (check the man page for usage info).