macos 从JAVA问题执行Unix系统命令
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Execute Unix system command from JAVA problem
提问by Ajith
I am facing a weird issue with executing a system command from JAVA code.
Actually i want to get the Mac OSXsystem information from my JAVA App.
For that im using
我在从 JAVA 代码执行系统命令时遇到了一个奇怪的问题。
其实我想Mac OSX从我的 JAVA 应用程序中获取系统信息。
为此，我正在使用
Runtime.getRuntime().exec("system_profiler -detailLevel full");
Runtime.getRuntime().exec("system_profiler -detailLevel full");
This is working fine.If i print the output,it is cool.
But i want to write this information to a plistfile for future use.For that im using the -xml argument of system_profiler.like,
这工作正常。如果我打印输出，它很酷。但我想将此信息写入plist文件以备将来使用。system_profiler为此，我使用.like的 -xml 参数，
String cmd = "system_profiler -detailLevel full -xml > "+System.getProperty( "user.home" )+"/sysinfo.plist";
Process p = Runtime.getRuntime().exec(cmd);
Basically this should create a plist file in the current users home directory.
基本上这应该在当前用户的主目录中创建一个 plist 文件。
But this seems to be not writing anything to file.
但这似乎没有向文件写入任何内容。
Am i missing something here ?
我在这里错过了什么吗？
回答by Christian.K
My Java is more than rusty, so please be gentle. ;-)
我的 Java 不仅仅是生锈，所以请保持温和。;-)
Runtime.exec()does not automatically use the shell to execute the command you passed, so the IO redirection is not doing anything.If you just use:
"/bin/sh -c system_profiler -detailLevel full > path/file.plist"Then the string will be tokenized into:
{ "/bin/sh", "-c", "system_profiler", "-detailLevel", "full", ">", "path/file.plist" }Which also wouldn't work, because
-conly expects a single argument.
Runtime.exec()不会自动使用 shell 来执行您传递的命令，因此 IO 重定向没有做任何事情。如果您只是使用：
"/bin/sh -c system_profiler -detailLevel full > path/file.plist"然后字符串将被标记为：
{ "/bin/sh", "-c", "system_profiler", "-detailLevel", "full", ">", "path/file.plist" }这也行不通，因为
-c只需要一个参数。
Try this instead:
试试这个：
String[] cmd = { "/bin/sh", "-c", "system_profiler -detailLevel full > path/file.plist" };
Process p = Runtime.getRuntime.exec(cmd);
Of course, you could also just read the output of your Processinstance using Process.getInputStream()and write that into the file you want; thus skip the shell, IO redirection, etc. altogether.
当然，您也可以使用读取Process实例的输出Process.getInputStream()并将其写入所需的文件；因此完全跳过shell，IO重定向等。
回答by paulsm4
Christian.K is absolutely correct. Here is a complete example:
Christian.K 是绝对正确的。这是一个完整的例子：
public class Hello {
static public void main (String[] args) {
try {
String[] cmds = {
"/bin/sh", "-c", "ls -l *.java | tee tmp.out"};
Process p = Runtime.getRuntime().exec (cmds);
p.waitFor ();
System.out.println ("Done.");
}
catch (Exception e) {
System.out.println ("Err: " + e.getMessage());
}
}
}
If you weren't using a pipe (|) or redirect (>), then you'd be OK with String cmd = "ls -l *.java", as in your original command.
如果您没有使用管道 ( |) 或重定向 ( >)，那么您可以使用String cmd = "ls -l *.java"，就像在您的原始命令中一样。
If you actually wanted to seeany of the output in your Java console window, then you'd ALSO need to call Process.getInputStream().
如果您真的想在 Java 控制台窗口中看到任何输出，那么您还需要调用Process.getInputStream().
Here's a good link: Running system commands in Java applications
这是一个很好的链接： 在 Java 应用程序中运行系统命令
