I'm looking a way to write running log of python which is executed by java app via script.
Let's say my script is:
import time
for x in range(120):
print("Running ", x)
time.sleep(1)
Here is my current solution:
Trigger script using java
String cmd = "python script.py";
var process = Runtime.getRuntime().exec(cmd, null, new File(sandboxPath));
Write log to new file:
String traceLogCmd = String.format("strace -p %s -s 9999 -e trace=write -o output.txt", process.pid());
Runtime.getRuntime().exec(traceLogCmd, null, new File(sandboxPath));
Now the problem is output.txt only has content whenever the python script is done executing so that I cannot tailf the output file.
Meanwhile if I execute python script.py and strace command dirrectly from terminal, the output is exactly what I expected.
Can someone correct me if I did something wrong or have a another way to get python log?
Thanks in advance.
Use ProcessBuilder instead of Runtime.exec(). More details: When Runtime.exec() won't
The following code will append to StringBuilder object output of the script sb.append(line);. It would not be difficult to write that content to a file.
Process p = new ProcessBuilder("sh", "-c", "python", "path-to-your-script").start();
String result = getCommandResult(p.getInputStream());
private static String getCommandResult(InputStream stream) throws IOException {
StringBuilder sb = new StringBuilder();
try (InputStreamReader isr = new InputStreamReader(stream);
BufferedReader in = new BufferedReader(isr)) {
String line;
while ((line = in.readLine()) != null) {
sb.append(line);
}
}
return sb.toString().trim();
}
Related
I need to start a server using bash, so I had created an UNIX shell , but I am not able to execute it with Java from Eclipse.
I tried the following code which doesn't work :
Process proc = Runtime.getRuntime().exec(./startServer);
Here is content of the startServer file :
#!/bin/bash
cd /Users/sujitsoni/Documents/bet/client
npm start
You can try the following two options.
Option 1
Process proc = Runtime.getRuntime().exec("/bin/bash", "-c", "<Abosulte Path>/startServer");
Option 2
ProcessBuilder pb = new ProcessBuilder("/bin/bash", "-c", "<Absolute Path>/startServer");
pb.directory(new File("<Absolute Path>"));
Process proc = pb.start();
A couple Of things can go wrong:
The path to the file you have given might be wrong for eclipse it can take relative path but from the command line, it will take the absolute path.
error=13, Permission denied - If the script file doesn't have required permissions. In your scenario, that might not the case as you are not getting any error.
At last, you are executing the script by java program so the output of your script will not be printed out. In your scenario, this might be the case. You need to capture the output of script from BufferedReade and print it. ( In your case server might have started but you are not seeing the logs/output of the script.
See the code sample below for printing output.
public static void main(String[] args) throws IOException, InterruptedException {
Process proc = Runtime.getRuntime().exec("./startServer");
proc.waitFor();
StringBuffer output = new StringBuffer();
BufferedReader reader = new BufferedReader(new InputStreamReader(proc.getInputStream()));
String line = "";
while ((line = reader.readLine()) != null) {
output.append(line + "\n");
}
System.out.println(output);
}
I'm currently using ProcessBuilder to run some file like test.out.
Here is some of my code
ArrayList cmd = new ArrayList();
cmd.add("sudo");
cmd.add("./test.out");
String s = "";
try{
ProcessBuilder pb = new ProcessBuilder(cmd);
pb.directory(new File("/myPath"));
pb.redircErrorStream(true);
Process p = pb.start();
InputStream is = p.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferReader br = new BufferReader(isr);
String line = "";
while((line = br.readLine()) !=null)
{
s+=line;
}
System.out.println(s);
}
I output the path which is correct("/myPath").
when I remove line
`cmd.add("sudo")`
the output will give me a String:
oneoflib:must be root. Did you forgot sudo?
But once I add
cmd.add("sudo");
there is nothing output.
Is there anyone whats wrong with it?
I can run sudo ./test.out from terminal which works fine.
I'm using eclipse BTW.
Thank you very much.
I guess that getting the error stream from the process could be beneficial here to help debug the problem.
This should help, consider the following bash script and let's call it yourExecutable. Let's also assume that it has all the proper permissions:
if [ "$EUID" -ne 0 ]
then echo "Please run as root"
exit
fi
echo "You are running as root"
When run without sudo it prints "Please run as root" other wise it prints "You are running as root"
The command, ie first argument in your list should be bash, if that is the shell you are using. The first argument should be -c so the commands will be read from the following string. The string should be echo <password> | sudo -S ./yourExecutable. This isn't exactly the best way to send the password to sudo, but I don't think that is the point here. The -S to sudo will prompt for the password which is written to stdout and piped over to sudo.
public static void main(String[] args) throws IOException {
Process process = new ProcessBuilder("bash", "-c", "echo <password> | sudo -S ./yourExecutable").start();
BufferedReader errorReader = new BufferedReader(new InputStreamReader(process.getErrorStream()));
String string;
while((string = errorReader.readLine()) != null){
System.out.println(string);
}
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
while((string = reader.readLine()) != null){
System.out.println(string);
}
}
Output on my machine looks like:
Password:
You are running as root
I can execute Linux commands like ls or pwd from Java without problems but couldn't get a Python script executed.
This is my code:
Process p;
try{
System.out.println("SEND");
String cmd = "/bash/bin -c echo password| python script.py '" + packet.toString() + "'";
//System.out.println(cmd);
p = Runtime.getRuntime().exec(cmd);
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
String s = br.readLine();
System.out.println(s);
System.out.println("Sent");
p.waitFor();
p.destroy();
} catch (Exception e) {}
Nothing happened. It reached SEND but it just stopped after it...
I am trying to execute a script which needs root permissions because it uses serial port. Also, I have to pass a string with some parameters (packet).
You cannot use the PIPE inside the Runtime.getRuntime().exec() as you do in your example. PIPE is part of the shell.
You could do either
Put your command to a shell script and execute that shell script with .exec() or
You can do something similar to the following
String[] cmd = {
"/bin/bash",
"-c",
"echo password | python script.py '" + packet.toString() + "'"
};
Runtime.getRuntime().exec(cmd);
#Alper's answer should work. Better yet, though, don't use a shell script and redirection at all. You can write the password directly to the process' stdin using the (confusingly named) Process.getOutputStream().
Process p = Runtime.exec(
new String[]{"python", "script.py", packet.toString()});
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(p.getOutputStream()));
writer.write("password");
writer.newLine();
writer.close();
You would do worse than to try embedding jython and executing your script. A simple example should help:
ScriptEngine engine = new ScriptEngineManager().getEngineByName("python");
// Using the eval() method on the engine causes a direct
// interpretataion and execution of the code string passed into it
engine.eval("import sys");
engine.eval("print sys");
If you need further help, leave a comment. This does not create an additional process.
First, open terminal and type "which python3". You will get the complete path of python3. For example "/usr/local/bin/python3"
String[] cmd = {"/usr/local/bin/python3", "arg1", "arg2"};
Process p = Runtime.getRuntime().exec(cmd);
p.waitFor();
String line = "", output = "";
StringBuilder sb = new StringBuilder();
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
while ((line = br.readLine())!= null) {sb = sb.append(line).append("\n"); }
output = sb.toString();
System.out.println(output);
I can execute Linux commands like ls or pwd from Java without problems but couldn't get a Python script executed.
This is my code:
Process p;
try{
System.out.println("SEND");
String cmd = "/bash/bin -c echo password| python script.py '" + packet.toString() + "'";
//System.out.println(cmd);
p = Runtime.getRuntime().exec(cmd);
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
String s = br.readLine();
System.out.println(s);
System.out.println("Sent");
p.waitFor();
p.destroy();
} catch (Exception e) {}
Nothing happened. It reached SEND but it just stopped after it...
I am trying to execute a script which needs root permissions because it uses serial port. Also, I have to pass a string with some parameters (packet).
You cannot use the PIPE inside the Runtime.getRuntime().exec() as you do in your example. PIPE is part of the shell.
You could do either
Put your command to a shell script and execute that shell script with .exec() or
You can do something similar to the following
String[] cmd = {
"/bin/bash",
"-c",
"echo password | python script.py '" + packet.toString() + "'"
};
Runtime.getRuntime().exec(cmd);
#Alper's answer should work. Better yet, though, don't use a shell script and redirection at all. You can write the password directly to the process' stdin using the (confusingly named) Process.getOutputStream().
Process p = Runtime.exec(
new String[]{"python", "script.py", packet.toString()});
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(p.getOutputStream()));
writer.write("password");
writer.newLine();
writer.close();
You would do worse than to try embedding jython and executing your script. A simple example should help:
ScriptEngine engine = new ScriptEngineManager().getEngineByName("python");
// Using the eval() method on the engine causes a direct
// interpretataion and execution of the code string passed into it
engine.eval("import sys");
engine.eval("print sys");
If you need further help, leave a comment. This does not create an additional process.
First, open terminal and type "which python3". You will get the complete path of python3. For example "/usr/local/bin/python3"
String[] cmd = {"/usr/local/bin/python3", "arg1", "arg2"};
Process p = Runtime.getRuntime().exec(cmd);
p.waitFor();
String line = "", output = "";
StringBuilder sb = new StringBuilder();
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
while ((line = br.readLine())!= null) {sb = sb.append(line).append("\n"); }
output = sb.toString();
System.out.println(output);
I'm trying to run a python script during the execution of my java code, because it will depend on the output received from the python script. So far I've tried using jythonc, unfortunately to no success, and now im trying to use the java Runtime and java Process to execute the python script.
Now I've run into a problem when trying to call the python script. I feel as though it doesn't even call the script because it takes less than a couple seconds to get to the next page....
Could the problem be how I am calling the python script?? I am trying to run this through a web application...
Here is some of my code:
String run = "cmd /c python duplicatetestingoriginal.py" ;
boolean isCreated = fwr.writeFile(BugFile, GD, 500, true, 5, "LET");
if(isCreated){
try{
r = Runtime.getRuntime();
p = r.exec(run);
BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream()));
BufferedReader stdError = new BufferedReader(new InputStreamReader(p.getErrorStream()));
String line = "";
while ((line = stdInput.readLine()) != null) {
System.out.println(line);
}
while ((line = stdError.readLine()) != null) {
errorW.write(line);
}
int exitVal = p.waitFor();
arrayList = fwr.readResults();
}catch(Exception e){
}
}
else{
// troubleshoot....
}
Instead of String for the command, split it to chunks and make a String[]. No need to state cmd /c, I think.
This is a sample code from my application:
//Running on windows
command = new String[4];
command[0]=directory.getCanonicalPath()+"/data/ExtenalApp.exe"; //extenal commandline app, not placed in path, but in subfolder
command[1]=directory.getCanonicalPath()+"/data/SomeFile.txt"; //file needed for the external app, sent as an argument
command[2]=arg1; //argument for the app
command[3]=arg2; //argument for the app
//Running on Mac
command = new String[6];
command[0]="python";
command[1]=directory.getCanonicalPath()+"/data/wp.py"; //path to the script
command[2]="-F"; //argument/Flag/option
command[3]="--dir="+path; //argument/option
command[4]="--filename="+filename; //argument/option
command[5]=argument; //argument/option
Process process = Runtime.getRuntime().exec(command);
process.waitFor();
process.destroy();
I don't handle the Input/Output streams because the script/app doesn't require input, and outputs only when finished, nothing important. Which might not be the case for you.