Making system calls in java

I want to join some split files into one. In command prompt I use COPY /B file.1+file.2 file to join the files. How can i do the same in my java application. Please show the code which I suppose will use getRuntime. Thanks in advance.

Well if there is a problem with system calls then can
you tell me if there is a class in java for
concetanating files. Not directly.
At present I am joing the files
by reading each byte from the files and writing them
to another file which takes hell lot of time. You should read the files in large chunks. Much much faster.
Thanks
in advance again. Also if you say about sequential
file class then please expalin a bit bcs I couldn't
implement it.Post the code you are having trouble with explaining what it should do and what it actually does.

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Quick question about making system calls

hello all
i have a simple quick question regarding making system calls. Basically I want to mimic the command "system" for perl. I am not quite sure how to do this for java.
any feedback would be appreciated.

look at:
java.lang.RunTime

Unix System Calls using Java

Hi!
Can anyone tell me how to do Unix System Calls in my Java program?
If possible please give me the java code for it taking one unix system call as an example.
Thanks in advance
Raj

do you mean firing off a shell command, or making actual kernel API calls or C library calls?
for shell commands, have a look at Runtime.exec(). for kernel calls, use JNI. the JNI FAQ mentions something called "shared stubs" that may be of use:
http://java.sun.com/products/jdk/faq/jnifaq.html
cheers,
p

Unix system() system call in Java

Hi,
system() call in Unix is very helpfull when you need to implement a piece of code that is already implemented in an exsiting utility.
Is there a way to achive a similar functionality?
To put it in simpler words - is there a way, in Java, to call some method that will invoke a Unix shell and will execute the command specified in the string that is past in?
Could you please CC the reply to [email protected]
Thanks,
-Michael

Runtime.exec()
> Could you please CC the reply to [email protected]
Certainly not.

System calls in Java

Any suggestions how one would perform a UNIX call inside a C++ or Java program?
Student who needs help.

If it is really a system call, then you will have to define and implement a "native" method.
o java method witha "native modifier".
o write a small c program that implements the method
If you define the native method, and then run java.h, the result is a header file for the c program.

System call fom Java code

Hi all
I hope someone over here might answer my problem.
I need to run a Shell script form my Java code, which does perform some operations like writing/copying files to a specific directory and my Java code then starts reading the files and do necessary stuff like parsing it for some info inside the file.
If I make a system call from my Java code, how do I know when the shell script is done executing completely? Just to make sure that my Java code execution starts only after the shell script has executed.
If anyone has come across such a scenario, please reply to this topic. A sample code wud be a bonus for me :)
Thanks
-Uday

If you've never used Runtime.exec, read this carefully first:
http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html
MOD

How do i make UNIX system calls in Java app?

Is it possible to make UNIX system calls in a java app? I.E. perform a file copy/move to another machine within a program.
Thanks,
Erik

If there is a command line tool then you use Runtime.exec() otherwise you have to use JNI.
If you want to access shared libraries you might want to look at www.swig.org

System Call by Java Application - [change path and run of the other progra]

public class A {
     public static void main (String[] args)
          System.out.println("Hi");
}I do have above A.java.
I am generating A.class from it.
A.class is in the following directory :
/home/sachin/work/Sample_Directory/bin/hello_filetest/
I have another program which makes System call.
But the problem is B.java is in the different directory :
/home/sachin/work/Sample_Directory/src/hello_filetest/
public class B {
     public static void main (String[] args) {
Process p1 = Runtime.getRuntime().exec("java A);
            BufferedReader stdInput = new BufferedReader(new
                 InputStreamReader(p1.getInputStream()));
while ((s = stdInput.readLine()) != null) {
                System.out.println(s);
{code}
        So, my question is how to change directory by system calls and execute the program
which is lying in other directory ????
Thank you.

The following code will call javac on a .java file, which will compile it into a .class file
     public static void javacTest() {
          JFileChooser jf = new JFileChooser();
          if (jf.showOpenDialog(null) != jf.APPROVE_OPTION) return;
          File file = jf.getSelectedFile();
          File dir = file.getParentFile();
          try {
               Process p = Runtime.getRuntime().exec("javac " + file.getName(), null, dir);
               IOUtils.pipe(p.getInputStream(), System.out);
               IOUtils.pipe(p.getErrorStream(), System.out);
          catch (IOException iox) {
               iox.printStackTrace();
     }Is that what you're trying to do, or are you trying to run the compiled (.class) file? Running your .class file should be basically the same as the above, assuming that you are not using any non j2se libraries, except that you need to take into account the package (if package is x.y, you must have file in ...src\x\y\foo.class - call "java x.y.foo" from src)

Issuing Solaris system calls through Java

How can I issue a system call to Solaris using Java? (i.e. Start a script, open a file, and similar)

Hi Srini,
This is just a suggestion, but try entering the following commands (in your SQL*Plus session) before executing your stored procedure:
set serveroutput on size 1000000
exec dbms_java.set_output(1000000)Hope this helps.
Good Luck,
Avi.

How to access system calls from java program?

i am having a doubt regarding accessing system calls from a Java program like accessing unix system calls from a c program.

Runtime.getRuntime().exec("line command here");
example:
Runtime.getRuntime().exec("ls -la");

System Call from Java, problem LD_LIBRARY_PATH

I use class Runtime to invoke Operating System Call.
I want to run OS command gpg (gnu program for encrypting/ decrypting files).
What is interesting, when I run my sqlplus script from system user (used for database installation) call ends with success.
Running script from other os users or machines ends with -1 code and error message:
"ld.so.1: gpg: fatal: libiconv.so.2: open failed: No such file or directory"
gpg uses libraries given LD_LIBRARY_PATH (/opt/gnupg/lib:/usr/lib:/usr/local/lib)
I think that is the problem. Is there a workaround for that??
Best regard
Grzegorz

Maybe related to the fact that the PATH environment variable is unset then re-initialized by Oracle to PATH = /usr/local/bin:/bin:/usr/bin. Try using absolute path for the OS commands.
Kuassi
- blog http://db360.blogspot.com/
- book http://db360.blogspot.com/2006/08/oracle-database-programming-using-java_01.html

Adding menu items and making system calls in AfterEffects (AE,CS3)

We are looking to do the following things via javascript in AfterEffects CS3. It does seem straight-forward, but am unable to find a good reference or example.
* Add at startup a menu item under "File" (or similar main menu) and have it call a script function when clicked.
* Have a script make an external system call (to launch an external application/executable with a few parameters)
Any insights on how to achieve this?
Many thanks!

I wanted to see if there was any update on this, I'm writing a series of tools and would love to create a custom menu for quick and easy access.
If it turns out there isn't an "easy" way to do this (env variables, special directory locations, javascripts) would anyone know if access to the menubar is possible from the Plugin API?
I'm fairly new to After Effects, just getting up-to-speed on the environment now... seeing if I can duplicate the functionality of some old Nuke scripts in AE.
thanks,
Rick_

Making system calls in Flex

- Can I make system calls to access the local file system? If
so, is there a sample?
- Can I make system calls to run local console
scripts/binaries and get the output back? If so, is there a sample?
Thanks,

"Greg Lafrance" <[email protected]> wrote in
message
news:gd8flp$sul$[email protected]..
> To be fair, Adobe's initial vision for AIR is not as a
technology that
> would
> permit you to create desktop apps that do all that
"regular" desktop apps
> do.
>
> Part of the reason is because they wanted to have a
solution that "starts"
> to
> blur the lines between online and desktop, but I suspect
another reason is
> because they wanted to get it out the door, and dealing
with the
> additional
> security considerations might delay that.
>
> That said, I'm right there with you, I am looking
forward to when AIR apps
> can
> execute native apps.
>
> One of the problems is that Adobe has "grown up" and now
is getting a
> touch
> stiff, though I still believe they will continue to be
one of the greatest
> software firms out there for the next 5 - 10 - 15+
years.
>
> Of course I work there, so I'm at least a bit biased.
But then again, I am
> a
> bit of a rebel against some aspects of Adobe (and
definitely against some
> aspects of the former Macromedia) culture.
Heh. Been there, done that. They stopped giving me t-shirts

System Call via Java Stored Procedure?

Within a Java stored procedure I do
a FTP Call to a remote Server.
The running FTP Process belongs to
the Oracle System User (Operating System: Linux).
Is there a possibility to run that FTP
call with a different operating system
user?

another example of invoking a Java Stored Prodedure from WITHIN a PL/SQL function? What's the issue here? A java stored procedure is a java class wrapped in PL/SQL. Consequently the invocation from with PL/SQL is a straightforward PL/SQL call.
So what is it that is troubling you?
Cheers, APC

Making System Calls

This question has two parts, though they are related. (My goal, in case anyone's curious, is to make a view that can find and index Dilbert cartoons saved on my hard drive.)
1. Can Java call system functions, such as "dir" (on a Windows PC), and catch the results? Not with something fancy, like native code, but just using pure Java?
2. Can Java run an application, given a specific path? (for example, run a Perl script)
thanks,
Andrew

Read the JavaDocs.
For directories and Files: java.io.File.list() or java.io.File.listFiles()
For executing command java.lang.RunTime.exec()
Dave

Making system calls in java

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