I'm performing the following code to execute linux commands in my android application that I'm creating:
public void RunAsRoot(String[] cmds){
Process p = Runtime.getRuntime().exec("su");
DataOutputStream os = new DataOutputStream(p.getOutputStream());
for (String tmpCmd : cmds) {
os.writeBytes(tmpCmd+"\n");
}
os.writeBytes("exit\n");
os.flush();
}
I want to know if there is a way to know what the command is returning after it is executing. for example, if I do "ls" I would like to see what the command wold normally output.
try this code :
try {
Process process = Runtime.getRuntime().exec("ls");
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(process.getInputStream()));
StringBuilder result=new StringBuilder();
String line = "";
while ((line = bufferedReader.readLine()) != null) {
result.append(line);
}
TextView tv = (TextView)findViewById(R.id.textView1);
tv.setText(result.toString());
}
catch (IOException e) {}
Let's go by a "String function" example
String shell_exec(String s)
{
String line="",output="";
try
{
Process p=Runtime.getRuntime().exec(new String[]{"sh","-c",s});
BufferedReader b=new BufferedReader(new InputStreamReader(p.getInputStream()));
while((line=b.readLine())!=null){output+=line+"\r\n";}
}catch(Exception e){return "error";}
return output;
}
Now just use it:
String s=shell_exec("ls /data/data/com.mycompany.myapp");
Related
I'm using java's exec() to run some *nix system commands, specifically a python script, but the problem is more general.
import java.io.*;
public class JRC {
public static void main(String args[]) {
String s[] = {"/bin/bash", "-c",
"source venv/bin/activate;python mergeExcel.py '/home/201811/'"};
try{
Process p = Runtime.getRuntime().exec(s);
}
catch (IOException e) {
System.out.println("exception: ");
e.printStackTrace();
}
}
}
The above code works, in accordance with the extent to which mergeExcel.py works.
However, I can't figure out how to print to stdout from python.
Here's my attempt, which only works if we exec() a simple string such as "ps -ef", rather than the array of strings i'm using.
try {
Process p = Runtime.getRuntime().exec(s);
BufferedReader stdInput = new BufferedReader(new
InputStreamReader(p.getInputStream()));
BufferedReader stdError = new BufferedReader(new
InputStreamReader(p.getErrorStream()));
while ((s = stdInput.readLine()) != null) {
System.out.println(s);
}
while ((s = stdError.readLine()) != null) {
System.out.println(s);
}
System.exit(0);
}
This actually results in a compilation error of incompatible types, java.lang.String instead of the required java.lang.String[].
How can I can print output from the source venv/.. command and the python command?
Thanks to the commenter, it's trivial to declare some temporary strings to print from stdout and stderr, though perhaps another user has a more elegant solution
try {
Process p = Runtime.getRuntime().exec(s);
BufferedReader stdInput = new BufferedReader(new
InputStreamReader(p.getInputStream()));
BufferedReader stdError = new BufferedReader(new
InputStreamReader(p.getErrorStream()));
String stdi;
while ((stdi = stdInput.readLine()) != null) {
System.out.println(stdi);
}
String stderr;
while ((stderr = stdError.readLine()) != null) {
System.out.println(stderr);
}
System.exit(0);
}
I'm trying to write a function that has the name of a service as parameter. The problem is that i can only start and stop a service in cmd ( in windows) only if i run it as administrator. How can i run cmd in java as administrator? Can you please help me?? Thanks
public String stop(String name) {
try {
List<String> command = new ArrayList<String>();
command.add("cmd.exe");
command.add("/c");
command.add("runas");
command.add("/user:Administrator");
command.add("\"net");
command.add("stop");
command.add(name + "\"");
System.out.println(command);
Process servicesProcess = new ProcessBuilder(command).start();
InputStream input = servicesProcess.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(input));
String line;
StringBuffer queryResult = new StringBuffer();
while ((line = reader.readLine()) != null) {
queryResult.append(line);
}
reader.close();
servicesProcess.destroy();
System.out.println(queryResult.toString());
if (queryResult.toString().toLowerCase().contains("failed") || queryResult.toString().toLowerCase().contains("error")) {
return "Failed #stop";
}
System.out.println("Stop service completed succesfully!");
return "Succes #stop";
} catch (IOException e) {
return "Failed #stop";
}
}
I also tried with this and still doesn't work
List<String> command = new ArrayList<String>();
command.add("cmd.exe");
command.add("/c");
command.add("Powrprof.dll");
command.add(",");
command.add("SetSuspendState");
command.add("net");
command.add("stop");
command.add(name);
System.out.println(command);
Process servicesProcess = new ProcessBuilder(command).start();
I'm trying to launch a process in java, read the output, write to the program, then read what it responds with. From all the other answers on SO, this is what I have come up with:
class Main
{
public static void main(String[] args) {
String line = "";
try {
ProcessBuilder pb = new ProcessBuilder("C:\\myProgram.exe");
Process p = pb.start();
BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
BufferedWriter output = new BufferedWriter(new OutputStreamWriter(p.getOutputStream()));
while ((line = input.readLine()) != null) {
System.out.println(line);
}
output.write("foo");
output.newLine();
output.flush();
while ((line = input.readLine()) != null) {
System.out.println(line);
}
p.destroy();
}
catch (IOException e){
}
}
}
It launches the program, and gives me the output just as expected.
When i write foo, I expect the program to come back with another response, but it never does.
What am I doing wrong?
I trying to run multiple command shells from Java. I am able to do that (and get the output in the console using PrintWriter). However, I want to be able to get the output of each command in a separate String. Is that possible?
Here is a part of the code :
File wd = new File("/bin");
Process proc = null;
BufferedReader in = new BufferedReader(new InputStreamReader(proc.getInputStream()));
PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(proc.getOutputStream())), true);
out.println("cd ..");
out.println("ls");
System.out.println("moving to /var directory");
out.println("cd /var/");
out.println("ls");
//get output of ls command in string variable
out.println("cd ..");
out.println("cd /etc/");
out.println("ls -a");
out.println("ps");
out.println("exit");
try {
String line;
while ((line = in.readLine()) != null) {
System.out.println(line);
}
proc.waitFor();
in.close();
out.close();
proc.destroy();
}
catch (Exception e) {
e.printStackTrace();
}
Have you tried putting a section like
StringBuilder builder = new StringBuilder();
String line = null;
while ((line = in.readLine()) != null) {
builder.append(line).append("\n");
}
String commandOutput = builder.toString();
after each command? Is that roughly what you are trying to achieve?
I am now on a linux machine. I have a Java program which would run some linux command, for example ps, top, list or free -m.
The way to run a command in Java is as follows:
Process p = Runtime.getRuntime().exec("free -m");
How could I collect the output by Java program? I need to process the data in the output.
Use Process.getInputStream() to get an InputStream that represents the stdout of the newly created process.
Note that starting/running external processes from Java can be very tricky and has quite a few pitfalls.
They are described in this excellent article, which also describes ways around them.
To collect the output you could do something like
Process p = Runtime.getRuntime().exec("my terminal command");
p.waitFor();
BufferedReader buf = new BufferedReader(new InputStreamReader(
p.getInputStream()));
String line = "";
String output = "";
while ((line = buf.readLine()) != null) {
output += line + "\n";
}
System.out.println(output);
This would run your script and then collect the output from the script into a variable. The link in Joachim Sauer's answer has additional examples of doing this.
As for some command need to wait for a while, add p.waitFor(); if necessary.
public static void main(String[] args) {
CommandLineHelper obj = new CommandLineHelper();
String domainName = "google.com";
//in mac oxs
String command = "ping -c 3 " + domainName;
String output = obj.executeCommand(command);
System.out.println(output);
}
private String executeCommand(String command) {
StringBuffer output = new StringBuffer();
Process p;
try {
p = Runtime.getRuntime().exec(command);
p.waitFor();
BufferedReader reader =
new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = "";
while ((line = reader.readLine())!= null) {
output.append(line + "\n");
}
} catch (Exception e) {
e.printStackTrace();
}
return output.toString();
}
The technicalities of calling an external process are quite involved. The jproc library helps abstracting over these by automatically consuming the output of the command and providing the result as a string. The example above would be written like this:
String result = ProcBuilder.run("free", "-m");
It also allows to set a timeout, so that your application isn't blocked by an external command that is not terminating.
public String RunLinuxGrepCommand(String command) {
String line = null;
String strstatus = "";
try {
String[] cmd = { "/bin/sh", "-c", command };
Process p = Runtime.getRuntime().exec(cmd);
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
while ((line = in.readLine()) != null) {
strstatus = line;
}
in.close();
} catch (Exception e) {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
e.printStackTrace(pw);
pw.flush();
String stackTrace = sw.toString();
int lenoferrorstr = stackTrace.length();
if (lenoferrorstr > 500) {
strstatus = "Error:" + stackTrace.substring(0, 500);
} else {
strstatus = "Error:" + stackTrace.substring(0, lenoferrorstr - 1);
}
}
return strstatus;
}
This functioin will give result of any linux command