Execute shell command

Hello,
i have a question about running external programs started by java.
i know this is possible and i also know how to, but i have a problem retrieving the output generated by the process.
there are a a few problems..
i need to run a sql script, i cannot use jdbc for this matter so i need to start SQLPlus the script demands some input parameters and if they are not yet given on the commandline it will ask for them during the execution of the script. this way i cannot run the execution in the background. i know i can send input afterwards but that just won't work.
another solution would be running the script in an external terminal like gnome-terminal or the doc command box, this solves my input parameter issue, but i cannot retrieve the output given by the programs.
is there a way to solve this problem or ..
Marc Bannink

Take care of the standard input to the process!
Process
The created subprocess does not have its own terminal or console. All its standard io (i.e. stdin, stdout, stderr) operations will be redirected to the parent process through three streams (Process.getOutputStream(), Process.getInputStream(), Process.getErrorStream()). The parent process uses these streams to feed input to and get output from the subprocess. Because some native platforms only provide limited buffer size for standard input and output streams, failure to promptly write the input stream or read the output stream of the subprocess may cause the subprocess to block, and even deadlock.

Similar Messages

Executing shell commands from Java.

I want to execute shell commands in Java using the Runtime.exec( String ) method.
The method works fine under Linux OS, but under Windows '98 the method didn't work at all!
For example the following call: Runtime.exec( "dir" ) throws an exception showing that the command was not completed. If I replace dir with ls under Linux all is good. What is the problem with the Microsoft Windows '98 ? Is there any solution at my problem ?!
thx in advance!

hey JSarmis,
You can help me... "ls" doesn't work for me on linux.. using Runtime.exec, some commands work, others don't... you may hold the key to what i need? How did u get "ls" to work?

How to Execute shell commands in OSB

Team,
My Requirement:
I have two sftp servers name ServerA and ServerB. Need to copy files from ServerA and place it on ServerB and change the file permissions to 777 after placing the files.
The user i am connecting to ServerB has the access to override file permissions.
Steps
1. With help of FTP adapter in OSB I am reading files from ServerA and writing on to ServerB -- Completed and is working.
2. How to override file permissions after placing the file ????? -- Yet to implement.
Please suggest me how can i accomodate 2nd step.
Thanks,
Suman V.

If by "execute shell commands" you mean actually
running a shell process (as opposed to just forking
and executing specified programs) then I'd advise
against it. The last thing you want is for the
clients to be running arbitrary commands on the
server. You don't want to make it possible for the
client to run "rm -fr /" on your server.Right.
I was assuming (perhaps with more optimism than is really warranted) that the OP was going to be in complete control of which commands were executed--that there'd be a small, fixed set in response to certain user actions.

Execute shell command from Java

Hi all,
I need some idea for executing shell script from Java programe.
For example i have start.sh script in /tmp/start.sh folder of unix server.
I want to execute shell script from local java code.
Any idea on this.

Hi,
Read the following articles/posts, maybe this could help you:
How to execute shell command from Java
Running system commands in Java applications | java exec example | alvinalexander.com
Want to invoke a linux shell command from Java - Stack Overflow

Execute Shell command in Panel SDK Mac

Hi,
I´d like to execute the following task with a Panel:
• render the active sequence
• when finished send the output video file to another application using Apple Script
The Panel SDK Examples are a great start. So the missing part is, how can I send a shell command that executes an AppleScript?
In the ExtendScript Toolkit I found a function that looks promising. But executing this script only pops up an alert window saying "failed". Here´s the code:
var test = UIAutomationSupport.helper.executeConsoleCommand("ls -l");
alert(test);
So does Premiere has an equivalent function like system.callSystem() in After Effects?
Thanks,
Thomas

Bruce, thanks for your support!
For those who are interested what bbb_999 refers to, here is how you can execute a shell command (in the example I use "osascript" to launch an AppleScript file):
In your html file you simply write these simple lines of code
<script type="text/javascript">
    function executeShellCommand(){
          var result = window.cep.process.createProcess('/usr/bin/osascript','/Users/myUserName/Desktop/test.scp t');
          alert(result.data+" "+result.err);
</script>
The first argument of createProcess() is the path to the shell tool.
That´s all. Hope this helps others.
Thomas

Execute shell command from within pascal code

Hello there,
I am trying to execute a shell command from within my pascal code. I use XCode together with FreePascal. I have tried something like:
exec ('program', 'options');
adding the 'Dos' unit to the Uses clause of my program.
Thus, e.g.,
exec ('mkdir', '/A')
to create a directory with the name 'A'.
However, my attempts so far were unsuccessful. Can anyone help me on this, and perhaps provide a simple example of how to do it right?
Thank you in advance,
Shane

In the mean time, I found the problem myself. I am just posting the solution here for anyone that is interested. My original solution was correct, in that the 'Dos' Unit must be added, and that the right command is 'exec'. There was however a problem with the correct path to the program that I wanted to invoke. In the shell, this program was accessible from anywhere. However, in the 'exec' command, the full path to the program must be given. Since I am not a Unix expert, I don't know the reason for this.
So, in summary, the solution is:
Uses Dos;
begin
exec ('full path to program', 'program options');
e.g.: exec ('/bin/sh', '/run.sh') to process the commands in the file /run.sh
end
Hope this may be of help to anyone else.
Shane
Mac OS X (10.3.9)
Mac OS X (10.3.9)
Mac OS X (10.3.9)

Executing shell command

hi
i waould like to know if any one can tell me how to execute a shell command or call an from within a class file.
i am required to write a program which creates a servlet file internally everytime it is run.
i want to know how to execute the shell command in java so that i can compile that file after creating the file from within the class file and not leave it to the user to do it.

Runtime.getRuntime().exec("<your_command>");

Dtrace script to capture time spent executing shell commands

Hi all,
My 1st dtrace script to capture time spent by oracle executing various commands, is this correct? It seems to work...
#!/usr/bin/sh
/usr/sbin/dtrace -n '
#pragma D option quiet
#pragma D option switchrate=10
syscall::exec:entry, syscall::exece:entry
/uid == 900/
self->t = timestamp;
syscall::exec:return, syscall::exece:return
/uid == 900/
printf("%-20d %s\n", (timestamp - self->t), curpsinfo->pr_psargs);
thanks for any feedback.
Regards
Stuart

Hi Stuart -
Just to be clear, you wanted to know the time Oracle takes to exec() a command, or to actually run a short-lived process from start to finish? The script accomplishes the former, but I'm curious why you'd want that particular value.
Michael

Executing shell commands in Java

Hi
I have managed to get my Java program to execute the 'who' command and read in the data from running that command. However, how can I run this command with the '-m' option. I thought it would be
Process proc = rt.exec("who -m");However when I run this, I get no data. Is there another way of running this command.
Many thanks
Sambo

Thanks for the link, its actually the tutorial I looked at to start using the exec method.
try{
               Runtime rt = Runtime.getRuntime();
               Process proc = rt.exec("who");
               InputStream stderr = proc.getInputStream();
               InputStreamReader isr = new InputStreamReader(stderr);
               BufferedReader br = new BufferedReader(isr);
               File file = new File("input.txt");
               BufferedWriter out = new BufferedWriter(new FileWriter(file));
               while ((line = br.readLine())!=null){
                    temp = line.split("\\s+");
                    for (int i = 0; i < temp.length; i++){
                        //System.out.println(temp);
This is my current code, and I can get an output from that. But as soon as I add a argument to the who command, it doesn't display anything. The who command displays the current users logged into a Linux system.
I have tried
Process proc = rt.exec("who -m");and
Process proc = rt.exec("who ", "-m");But no luck.
Maybe I have to specify it as another argument, but not to sure how to do that.
Again many thanks

Running Shell Commands (not Executable) in Unix from Java

What are my options to run shell commands from Java?
My goal is to change my existing shell environment variables to some new ones provided by .anotherProfile.
Using an executable from Java is not an option because it does not work i.e. ( exec(". /home/.profile") ) brings up errors.
Someone has suggested that I start a child shell with that profile and work from there, but I'm unfamiliar with that sort of syntax and programming in general.
Any good help equals duke dollars :)

Well there are some possibilities. In the original thread you mentioned that you wanted the shell script to be executed to change some enviroment parameters of the shell the JVM is executing in.
If so, and you are able to rewrite the profile so you can parse it manually. Then you can change some environment setting by writing the JNI wrappers for the getenv and setenv system calls. (Check your man pages)
That will change the environment. I am just wondering what good it will do for you? What's use of sourcing the profile in a JVM?

Error while Executing Unix Shell Commands Using Runtime clas

I am trying to run the following code in java on unix machine to execute cat command.
Runtime runtime = Runtime.getRuntime();
          try {
               System.out.println("before catexecute");
               Process process = runtime.exec("cat /export/home/shankerr/local.profile > /export/home/shankerr/local1.txt");
               try {
                    if (process.waitFor() != 0) {
                    System.err.println("exit value = " +
                              process.exitValue());
                    catch (InterruptedException e) {
                    System.err.println(e);
But i get the following error on the console
exit value = 2
cat: cannot open >
cat: cannot open /export/home/shankerr/local1.txt
The same command if i run on unix console directly it creates a new file and copies the content into the new file local1.txt
kindly help me on the same

The redirection operator > along with stuff like pipe | history !$ etc. is interpreted by the shell, not by the cat program.
When you do cat X > Ycat only sees the X. The rest is interpreted by the shell to redirect the cat program's stdout.
However, when you Runtime.exec(), you don't have the shell, so cat sees X > Y as its arguments, and interprets them all as file names. Since there's no file named > you get the error.
The solution is to first man cat on your system and see if it happens to have a -o or somesuch operator that lets it (rather than the shell) send its output to a file. If not, then you need to invoke a shell, and pass it cat and all of cat's args as the command to execute.
Read the man pages for you shell of choice, but for bash, I believe you'd give Runtime.exec() something like /bin/bash -c 'cat X > Y'

Command not found error while executing shell programs in terminal

I have written one sample shell program.
while executing shell program in terminal,it shows COMMAND NOT FOUND error.
How to slove this.

Post the "Actual" error. It says more than command not found.
Post your script.
Post the output from:
echo $PATH
Post the output from:
which name_of_command_not_found

How to invoke BASH shell and execute a command in that shell in Windows 98

Hello, I have a problem and if somebody will help me, I will be very glad. Thank you.
I am using BASH shell on Windows 98 OS by means of CYGWIN. And I want to invoke this BASH shell and execute a preprogrammed command in the shell (./scan fileName.txt) from a JAVA program. But so far, I am not sucessful. I can not read or write anything from / to BASH shell. It either blocks and freezes (When I use waitFor( ) ) or appears and disappears without executing scan command (When I do not use waitFor( ) ). My code is like this:
// This method is used for compiling a file.
// It invokes BASH shell and executes "./scan fileName.txt" command
public void compileFileMethod () {
try {
Process proc = ( Runtime.getRuntime() ).exec ("C:\\MyDocuments\\CYGWIN.BAT); //I also tried to add -c ./scan fileName.txt after .BAT );
// I also tried to write "C:\\MyDocuments\\BASH.EXE" but it did not help
OutputStream ostr = proc.getOutputStream();
BufferedWriter bw = new BufferedWriter ( new OutputStreamWriter (ostr) );
InputStream istr = proc.getInputStream();
BufferedReader br = new BufferedReader ( new InputStreamReader (istr) );
InputStream errorStr = proc.getErrorStream();
BufferedReader errorBr = new BufferedReader ( new InputStreamReader (errorStr) );
bw.write("scan case40.10.txt"); /* I am trying to input the scan command to the shell,but it is not working*/
bw.flush();
Vector list = new Vector (1) ;
String str;
while ( (str = br.readLine() ) != null) {
list.addElement(str);
} // End of while
Enumeration enumForList = list.elements();
while ( enumForList.hasMoreElements() ) {
String tempString;
tempString = ( String ) enumForList.nextElement();
System.out.println(tempString); // I am trying to read the outputs of the scan command but it is not reading (I can not see any output)
I tried with and without waitFor( ), it did not work
// wait for command to terminate
proc.waitFor();
// close streams
br.close();
bw.close();
errorBr.close();
} // End of try
catch ( IOException ioe ) {
JOptionPane.showMessageDialog (null, "Input / output error occured while compiling file ", "Error", JOptionPane.ERROR_MESSAGE);
} // End of catch
catch ( SecurityException se ) {
JOptionPane.showMessageDialog (null, "Security error occured while compiling file ", "Error", JOptionPane.ERROR_MESSAGE);
catch ( InterruptedException ie ) {
JOptionPane.showMessageDialog (null, "Interruption error occured while compiling file ", "Error", JOptionPane.ERROR_MESSAGE);
} // End of method compileFileMethod
// Thank you for your helps and time.

You cannot invoke BAT files directly, you have to invoke the program that run those files which is your Windows 98 shell. For example (under windows 2000), i would invoke "cmd.exe sricpt.bat some args", rather than "script.bar some args".
Hope this will help you out.

How to execute a shell command in java?

here, my environment is redhat 7, jdk 1.5.
i don't know how to use the shell command in java.
i want to use this function:
#include <stdlib.h>
int system(const char * string);
please give me some ideas. and Thank you so much if coming with a little demo.

i know i should use JNI. because i have to use C lib.
but i have already use JNI to wrapper the original code the cpp code and java code is :
//: appendixb:UseObjImpl.cpp
//# Tested with VC++ & BC++. Include path must
//# be adjusted to find the JNI headers. See
//# the makefile for this chapter (in the
//# downloadable source code) for an example.
#include <jni.h>
#include <stdlib.h>
extern "C" JNIEXPORT void JNICALL
Java_UseObjects_changeObject(
JNIEnv* env, jobject, jobject obj) {
jclass cls = env->GetObjectClass(obj);
jfieldID fid = env->GetFieldID(
cls, "aValue", "I");
jmethodID mid = env->GetMethodID(
cls, "divByTwo", "()V");
int value = env->GetIntField(obj, fid);
printf("Native: %d\n", value);
env->SetIntField(obj, fid, 6);
env->CallVoidMethod(obj, mid);
value = env->GetIntField(obj, fid);
system("preprocess -path sha.c");
printf("Native: %d\n", value);
} ///:~
//: appendixb:UseObjects.java
// From 'Thinking in Java, 2nd ed.' by Bruce Eckel
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
class MyJavaClass {
public int aValue;
public void divByTwo() { aValue /= 2; }
public class UseObjects {
private native void
changeObject(MyJavaClass obj);
static {
// System.loadLibrary("UseObjImpl");
// Linux hack, if you can't get your library
// path set in your environment:
System.load(
"/root/jproj/UseObjImpl.so");
public static void main(String[] args) {
UseObjects app = new UseObjects();
MyJavaClass anObj = new MyJavaClass();
anObj.aValue = 2;
app.changeObject(anObj);
System.out.println("Java: " + anObj.aValue);
} ///:~
i modify this two file which is from TIJ-2edition.
the output is
Native: 2
Native: 3
Java: 3
but what i want to be executed "preprocess -path sha.c" does not work.
i have change the command to, such as "df", "ls" etc. but none of them works
please help me.

How to execute a shell command?

What class and method should I use to set an environment variable on a local system? And how do I execute a shell command in Java?
Thanks!

I don't know about setting environment variables from java, but I do know how to execute system commands (and from there you could modify environment variables).
Use Runtime.getRuntime().exec()
There are quite a few pitfalls with using this though...
1. It's platform dependent
2. Doing this creates a Process. If this process has output, you need to read this, otherwise the output buffer will overflow, and that would be bad... Input is not so bad (either supplying it or not ;)
3. If you use Win for example, and want to do a "dir", there are complications, as there is no dir.exe file, and hence it can't be executed... Do a search for this topic, there's plenty on how to get around it.
Anyway, there's plenty more info on Runtime.getRuntime().exec(), have a look around.
Cheers,
Radish21

Execute shell command

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