java bash 命令问题
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java bash command problem
提问by Maverick
Possible Duplicate:
How do I get the bash command exit code from a Process run from within Java?
Hi, I have a program which is a simple decrypts another file using bash command ./nv0914 < nv0914.challengewhere nv0914 is a unix executable file and nv0914.challenge is a text file used for decryption. Now when i am running it from bash and just after that if I run the command echo ${?}I am getting a value 0, which is good. But now I have to implement an attack and for that I need to get the exit value printed through a java program. I have this code as if now:
嗨，我有一个程序，它是使用 bash 命令简单解密另一个文件的程序，./nv0914 < nv0914.challenge其中 nv0914 是 unix 可执行文件，而 nv0914.challenge 是用于解密的文本文件。现在，当我从 bash 运行它时，紧接着如果我运行命令，echo ${?}我会得到一个值 0，这很好。但是现在我必须实施攻击，为此我需要通过 java 程序打印退出值。我现在有这个代码：
import java.io.*;
import java.util.*;
public class ExecBashCommand {
public static void main(String args[]) throws Exception {
Runtime runtime = Runtime.getRuntime();
Process process = runtime.exec("./nv0914 < nv0914.challenge");
/* InputStream is = process.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String line;*/
System.out.println("Exit Code: "+process.exitValue());
//System.out.printf("Output of running %s is:", Arrays.toString(args));
/* while ((line = br.readLine()) != null) {
System.out.println(line);
}*/
}
}
But this program is giving me an error :
但是这个程序给了我一个错误：
Exception in thread "main" java.lang.IllegalThreadStateException: process hasn't exited
at java.lang.UNIXProcess.exitValue(UNIXProcess.java:172)
at ExecBashCommand.main(ExecBashCommand.java:16)
Any suggestions as to how to get the exit value. Thanks
关于如何获得退出值的任何建议。谢谢
回答by Petey B
Have you tried calling process.waitFor()before you try and read the exit value?
process.waitFor()在尝试读取退出值之前，您是否尝试过调用？
