I am using Runtime.getRuntime().exec() to run a shell script from Java code. The code works fine when I pass the parameter as string
Runtime.getRuntime().exec("sh test.sh")
Since I have to pass additional arguments which are paths with spaces, so I replaced String with String array.
String[] cmd = {"sh test.sh", "/Path/to my/resource file"};
Runtime.getRuntime().exec(cmd)
I also tried with
String[] cmd = {"sh test.sh"};
Runtime.getRuntime().exec(cmd)
But neither of them worked. It's throwing an exception:
java.io.IOException: Cannot run program "sh test.sh":
java.io.IOException: error=2, No such file or directory
Why is the same script file when passed as String worked and when used with String array is throwing exception? How can I make this work with string array as argument to Runtime.exec()?
First string became the command. There is no file 'sh test.sh' to be executed.
Change
String[] cmd = {"sh test.sh", "/Path/to my/resource file"};
to
String[] cmd = {"sh", "test.sh", "/Path/to my/resource file"};
(In general use process builder API)
Related
I have two jar files named test1.jar and test2.jar.
In order to execute a function in in this jar file, I run below command in cmd.
“java getOutput argument1 argument2 argument3 argument4”
As a pre-requisite, I have set the following entries in my system environment variables to execute the java function using the above command.
1.CLASSPATH=C:\Folder\test1.jar;C:\Folder\test2.jar;C:\Program Files\Java\jre1.8.0_181\lib\plugin.jar
2.JAVA_BIN=C:\Program Files\Java\jre1.8.0_181\bin
3.JAVA_HOME=C:\Program Files\Java\jre1.8.0_181
4.PATH = C:\Program Files\Java\jre1.8.0_181\bin
The output of the above command is a string.
I have another java code. I have to capture the above string output in a variable in my java program and I am able to do this by using below java code in eclipse.
String strArgs= strArg1+" "+strArg2+" "+strArg3+" "+strArg4;
Process p=Runtime.getRuntime().exec("cmd /c java getOutput "+strArgs+"");
BufferedReader input =new BufferedReader(new
InputStreamReader(p.getInputStream()));
String strOutput = input.readLine();
if (strOutput != null) {
System.out.println(strOutput);
String strVariable = strOutput;
input.close();
}else {
System.out.println("FAIL- Output not generated");
}
In order to execute the above code on unix, I replace Line 2 with "Process p=Runtime.getRuntime().exec("usr/bin/java getOutput "+strArgs+"");" , convert the eclipse java project into a jar file named automation.jar. And I try to execute this jar file on unix using the below command .
`java -cp automation.jar Package.MainClass.'
When I run the code I get the output as null. But when I run the command on windows command prompt I get the output string.
Could you please help me on how to set the system variables in unix and perform the above operation to generate the string output.
Please let me know if any additional information required.
cmd is windows only. Unix uses a shell. But you shouldn't need either here. Just remove the cmd call.
Process p = Runtime.getRuntime().exec("java getOutput " + strArgs);
If it can't find Java, you can read the JAVA_BIN (or JAVA_HOME) from the environment.
String java_bin = System.getenv("JAVA_BIN");
Process p = Runtime.getRuntime().exec(java_bin + "/java getOutput " + strArgs);
Finally, your environment variables look like Windows path variables. Make sure they're correct for your Unix environment (Unix doesn't have a "C" drive).
I have a java code that execute a powershell script.My parameters are in a string array that I got from user.
String sentence = clientinp.readUTF();
String[] parts = sentence.split(",");
How should I put the parameters to the script every time I execute the code?
I tried this code:
String command = "powershell.exe $Add-DnsServerResourceRecordA -ZoneName -Name -IPv4Address -TimeToLive";
But I don't know how can I pass this array to powershell.What should I do?
Use a ProcessBuilder. You have to put each parameter (including path to the program) as items to an array or list and pass it to the constructor of ProcessBuilder.
for example:
String[] arguments = {"powershell.exe", "$Add-DnsServerResourceRecordA", "-ZoneName", "[your zone name]", "-Name", "[your name]", "-IPv4Address", "[your ipv4 address]", "-TimeToLive", "[your TTL]"};
ProcessBuilder processBuilder = new ProcessBuilder(arguments);
Process process = processBuilder.start();
As an alternative you can use Runtime.getRuntime().exec()
I'm working with the java ProcessBuilder class to start an instance of nmap on my windows workstation.
The following code produces an exception:
java.io.IOException: Cannot run program "C:\Program Files (x86)\Nmap\nmap.exe -T4 -A -v --max-scan-delay 0ms --min-rate 1000000 --max-retries 0 -oX - 192.168.1.1 ": CreateProcess error=2, The system cannot find the file specified
The value of command is:
C:\Program Files (x86)\Nmap\nmap.exe -T4 -A -v --max-scan-delay 0ms --min-rate 1000000 --max-retries 0 -oX - 192.168.1.1
Running the command is generated right in a command window executes properly.
Any ideas?
String command = this.getCommand().toString();
ExecutionResults results = new ExecutionResults();
ProcessBuilder procBuilder = new ProcessBuilder(new String[]{command.toString()});
try {
Process e = procBuilder.start();
results.setErrors(this.convertStream(e.getErrorStream()));
results.setOutput(this.convertStream(e.getInputStream()));
You're passing the whole command (including parameters) as a single parameter of the ProcessBuilder constructor. It takes a String[], where the first item should be the path to the executable, and the other items should be the parameters. Try
command.split(" ")
instead of
new String[]{command.toString()}
Edit: I see that you have spaces in your path, that will break it :( you could try splitting the executable path and the arguments into two strings. And the constructor argument will be a String[] containing the path itself as the first item and then an array of the parameters split by space.
OR: if you don't mind not using the ProcessBuilder.. this is much simpler:
Process e = Runtime.getRuntime().exec(command);
It is simple from the exception itself,
java.io.IOException: Cannot run program "C:\Program Files (x86)\Nmap\nmap.exe -T4 -A -v --max-scan-delay 0ms --min-rate 1000000 --max-retries 0 -oX - 192.168.1.1 ": CreateProcess error=2, The system
Process builder taking the whole line thinking it is as an executable and trying to run that. Just use the below example,
ProcessBuilder procBuilder = new ProcessBuilder(new String[]{"C:\Program Files (x86)\Nmap\nmap.exe"});
procBuilder.start();
This will work fine. So this is not an issue what you think that java is unable to find the executable. It is taking whole line as an executable. Better you do like below,
ProcessBuilder procBuilder = new ProcessBuilder(new String[]{"C:\Program Files (x86)\Nmap\nmap.exe", "-T4", "-A"}); //add all params
procBuilder.start();
Try this, it should work fine
As the other answers have indicated, your immediate problem is that you're passing an entire command line as if it's the name of a program to run. CreateProcess is looking for a program named "C:\Program Files (x86)\Nmap\nmap.exe -T4 -A etc" and failing to find it.
If you have a string containing a command to run (a program name with arguments, redirection, and so on), then the simplest way to run it is to launch it via the command line processor. Here's a simple example of doing that:
public static void main(String[] args) throws IOException, InterruptedException {
String command = "dir /w";
ProcessBuilder procBuilder = new ProcessBuilder(new String[]{"cmd", "/c", command});
procBuilder.redirectInput(Redirect.INHERIT);
procBuilder.redirectOutput(Redirect.INHERIT);
procBuilder.redirectError(Redirect.INHERIT);
Process p = procBuilder.start();
int ecode = p.waitFor();
System.err.println("Exit code " + ecode);
}
It might be because of a couple of reasons from my experience
Firewall would be removed certain files necessary for the installer. So would suggest to uninstall and reinstall
Can also be because of spaces in the folder path, would suggest to install in new folder which does not have spaces in the path.
I am trying to copy a file. Here is the source. Note, des is string variable containing the URL.
Process process = Runtime.getRuntime().
exec("cmd.exe\t/c\tcopy\t"+source+"\t"+des);
Can anyone tell me why it does not work?
I think you should use FileUtils.copyFile() but anyways try this.
String[] command = new String[5];
command[0] = "cmd";
command[1] = "/c";
command[2] = "copy";
command[3] = "test.java";
command[4] = "D:";
Process p = Runtime.getRuntime().exec (command);
Instead of passing your command as a single string construct an array and than pass it to exec.
I tried this
String command = "cmd /c copy test.java D:";
worked fine for me.
Advice:
Use ProcessBuilder to construct the Process.
That automatically takes care of '2' - break the command into parts.
Merge the output streams (not entirely necessary, but makes it simpler to ..).
Consume (and display) the output streams.
But in general, read and implement all the recommendations of When Runtime.exec() won't.
Runtime.exec, I believe, send the string to the command processor cmd.exe. So this is running cmd.exe, running another cmd.exe inside it, and passing your arguments. I don't have a Windows machine to test it on (thank Gods) but I think there are arguments to cmd.exe to tell it to run the arguments as a command line.
Why not just use FileUtils.copyFile()?
I've created a standalone java application in which I'm trying to change the directory using the "cd" command in Ubuntu 10.04 terminal. I've used the following code.
String[] command = new String[]{"cd",path};
Process child = Runtime.getRuntime().exec(command, null);
But the above code gives the following error
Exception in thread "main" java.io.IOException: Cannot run program "cd": java.io.IOException: error=2, No such file or directory
Can anyone please tell me how to implement it?
There is no executable called cd, because it can't be implemented in a separate process.
The problem is that each process has its own current working directory and implementing cd as a separate process would only ever change that processes current working directory.
In a Java program you can't change your current working directory and you shouldn't need to. Simply use absolute file paths.
The one case where the current working directory matters is executing an external process (using ProcessBuilder or Runtime.exec()). In those cases you can specify the working directory to use for the newly started process explicitly (ProcessBuilder.directory() and the three-argument Runtime.exec() respectively).
Note: the current working directory can be read from the system property user.dir. You might feel tempted to set that system property. Note that doing so will lead to very bad inconsistencies, because it's not meant to be writable.
See the link below (this explains how to do it):
http://alvinalexander.com/java/edu/pj/pj010016
i.e. :
String[] cmd = { "/bin/sh", "-c", "cd /var; ls -l" };
Process p = Runtime.getRuntime().exec(cmd);
Have you explored this exec command for a java Runtime, Create a file object with the path you want to "cd" to and then input it as a third parameter for the exec method.
public Process exec(String command,
String[] envp,
File dir)
throws IOException
Executes the specified string command in a separate process with the specified environment and working directory.
This is a convenience method. An invocation of the form exec(command, envp, dir) behaves in exactly the same way as the invocation exec(cmdarray, envp, dir), where cmdarray is an array of all the tokens in command.
More precisely, the command string is broken into tokens using a StringTokenizer created by the call new StringTokenizer(command) with no further modification of the character categories. The tokens produced by the tokenizer are then placed in the new string array cmdarray, in the same order.
Parameters:
command - a specified system command.
envp - array of strings, each element of which has environment variable settings in the format name=value, or null if the subprocess should inherit the environment of the current process.
dir - the working directory of the subprocess, or null if the subprocess should inherit the working directory of the current process.
Returns:
A new Process object for managing the subprocess
Throws:
SecurityException - If a security manager exists and its checkExec method doesn't allow creation of the subprocess
IOException - If an I/O error occurs
NullPointerException - If command is null, or one of the elements of envp is null
IllegalArgumentException - If command is empty
This command works just fine
Runtime.getRuntime().exec(sh -c 'cd /path/to/dir && ProgToExecute)
Using one of the process builder's method we could pass the directory where we expect the cmd to be executed. Please see the below example. Also , you can mention the timeout for the process, using wait for method.
ProcessBuilder builder = new ProcessBuilder("cmd.exe", "/c", cmd).directory(new File(path));
Process p = builder.start();
p.waitFor(timeoutSec, TimeUnit.SECONDS);
In the above code, you can pass the file object of the path[where we expect the cmd to be executed] to the directory method of ProcessBuilder
My preferred solution for this is to pass in the directory that the Runtime process will run in. I would create a little method like follows: -
public static String cmd(File dir, String command) {
System.out.println("> " + command); // better to use e.g. Slf4j
System.out.println();
try {
Process p = Runtime.getRuntime().exec(command, null, dir);
String result = IOUtils.toString(p.getInputStream(), Charset.defaultCharset());
String error = IOUtils.toString(p.getErrorStream(), Charset.defaultCharset());
if (error != null && !error.isEmpty()) { // throw exception if error stream
throw new RuntimeException(error);
}
System.out.println(result); // better to use e.g. Slf4j
return result; // return result for optional additional processing
} catch (IOException e) {
throw new RuntimeException(e);
}
}
Note that this uses the Apache Commons IO library i.e. add to pom.xml
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.10.0</version>
</dependency>
To use the cmd method e.g.
public static void main(String[] args) throws Exception {
File dir = new File("/Users/bob/code/test-repo");
cmd(dir, "git status");
cmd(dir, "git pull");
}
This will output something like this: -
> git status
On branch main
Your branch is up to date with 'origin/master'.
nothing to commit, working tree clean
> git pull
Already up to date.
Try Use:
Runtime.getRuntime.exec("cmd /c cd path");
This worked
Runtime r = Runtime.getRuntime();
r.exec("cmd /c pdftk C:\\tmp\\trashhtml_to_pdf\\b.pdf C:\\tmp\\trashhtml_to_pdf\\a.pdf cat output C:\\tmp\\trashhtml_to_pdf\\d.pdf");
The below did not work
While using array command did NOT WORK
String[] cmd = {"cmd /c pdftk C:\\tmp\\trashhtml_to_pdf\\b.pdf C:\\tmp\\trashhtml_to_pdf\\a.pdf cat output C:\\tmp\\trashhtml_to_pdf\\d.pdf"}; r.exec(cmd);
FYI am using utility to check OS if its windows above will work for other than windows remove cmd and /c
I had solved this by having the Java application execute a sh script which was in the same directory and then in the sh script had done the "cd".
It was required that I do a "cd" to a specific directory so the target application could work properly.