JAVA Runtime.getRuntime().exec(cmd)的正确格式

Runtime.getRuntime().exec(cmd)“ls -alh >> output.txt”);

当有重定向时，是不能执行的

这时候看一看官方的文档：

public Process exec(String command) throws IOExecption 
public Process exec(String command,String [] envp) throws IOExecption 
public Process exec(String command,String [] envp,File dir) throws IOExecption 
public Process exec(String[] cmdarray) throws IOExecption 
public Process exec(String[] cmdarray,String [] envp) throws IOExecption 
public Process exec(String[] cmdarray,String [] envp,File dir) throws IOExecption

重载方法。使用第二种：

String[] cmd = {"/bin/bash","-c","nohup sleep 3 >> 1.txt &"};
Process process = Runtime.getRuntime().exec(cmd);