Call Linux command from Java Application

Get Started
1

Hi all,

i tried to run Linux command from Java Application.

Here i past my code:-

package com;

public class linux_java {
public static void main(String args) {
try {
String command = “cut -f 2,5 ABC/test.tab>ABC/test1.tab”;
final Process process = Runtime.getRuntime().exec(command);
int returnCode = process.waitFor();
System.out.println("Return code = " + returnCode);
} catch (Exception e) {
e.printStackTrace();
}
}
}

result:

Return code =1

But no new file was created.

But when i run “cut -f 2,5 ALLIANCEHOURLYFILES/test.tab>ALLIANCEHOURLYFILES/test1.tab” command from Linux terminal it’s works.

please help me.

Thanks!
Vaskar

2

Try using the full path to cut (probably /bin/cut or /usr/bin/cut), since if I’m not mistaken Java doesn’t know it’s supposed to look for your program in your PATH.

Also make sure your program is running on the right directory.

3

I tried but it didn’t work…

4

Add
System.out.println( System.getProperty(“user.dir”) );
to get the current working directory, ABC should be a subdirectory of it.

Alternately, use absolute paths for everything.

5

I changed my code

package com;

import java.io.*;

public class linux_java {
public static void main(String args) {
try {
String command =
“/bin/cut -f 2,5 /var/www/html/final_java/ABC/qavhourly.tab”;
BufferedWriter out = new BufferedWriter(new FileWriter(
new File(
“/var/www/html/final_java/ABC/testqavhourly.tab”), true));
final Process process = Runtime.getRuntime().exec(command);
BufferedReader buf = new BufferedReader(new InputStreamReader(
process.getInputStream()));
String line;
while ((line = buf.readLine()) != null) {
out.write(line);
out.newLine();
}
buf.close();
out.close();
int returnCode = process.waitFor();
System.out.println("Return code = " + returnCode);
} catch (Exception e) {
e.printStackTrace();
}
}
}

the code is works properly.But it takes long time.Because the file size is too large i.e nearly 1 GB.Is there any way to reduce the time? pls help me…

6

I need to execute Linux commands in terminal with the help of Java GUI . I also need to store the result back to a file.Please help!!