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Executing custom Commands in Java

With this, we can execute "build in" commands in java. However if we want to run some custom commands from this, Changing "pwd" to "device_id -l" doesn't work. "device_id -l" should list all the ids of attached devices of currently host. if "device_id -l" is executed in terminal itself. it works fine. There is not a question for the "build in" bash commands. Thank you.
String cmd = "pwd";
Runtime run = Runtime.getRuntime();
Process pr = run.exec(cmd);
pr.waitFor();
BufferedReader buf = new BufferedReader(new InputStreamReader(pr.getInputStream()));
String line = "";
while ((line=buf.readLine())!=null)
System.out.println(line);
We can excuate

You can try using ProcessBuilder.
// create process
ProcessBuilder pb = new ProcessBuilder("/bin/bash", "-c", "device_id", "-l");
// start process
Process p = pb.start();
// wait for process exit
p.waitFor();
// read process output
BufferedReader buf = new BufferedReader(newInputStreamReader(p.getInputStream()));
String line = "";
while ((line=buf.readLine())!=null)
System.out.println(line);

You need to split your command+arguments to a String array. In your case, if you want to execute "device_id -l", split that into an array like this:
String[] cmd = new String[] {"/full/path/to/device_id", "-l"};
Process pr = Runtime.getRuntime().exec(cmd);
And, you might want to use ProcessBuilder.
String[] cmd = new String[] {"/full/path/to/device_id", "-l"};
ProcessBuilder pb = new ProcessBuilder(cmd);
Process pr = pb.start();
Finally, you'll have to take into account that Java does not look for executables in PATH (like command shell does), you'll have to provide full path to the executable/script that you want to execute (or it has to be in the working directory; you can set the working directory with ProcessBuilder.directory(File)).
See also: Difference between ProcessBuilder and Runtime.exec()

How to execute terminal command in specific directory from java

I am trying to execute originate command in specific directory "/usr/local/freeswitch/bin", In bin I have to run executable file fs_cli by ./fs_cli command, In fs_cli I have to execute following command
originate loopback/1234/default &bridge(sofia/internal/1789)
Its working fine from terminal, The same command can be executed from bin
./fs_cli -x "originate loopback/1234/default &bridge(sofia/internal/1789)"
I tried folowing java program to do the above task
Process pr = Runtime.getRuntime().exec("./fs_cli -x \"originate loopback/1234/default &bridge(sofia/internal/1789#192.168.0.198)\"");
BufferedReader br = new BufferedReader(new InputStreamReader(pr.getInputStream()));
String str = null;
while ((str = br.readLine()) != null) {
System.out.println(str);
}
I have creted symbolic link of fs_cli and placed in current location
The above program is showing following output
Output
-ERR "originate Command not found!
As far as I am concerned whwn above command is working fine with terminal it should be the same from java, So it shows I am wrong somewhere
Please help me to sort out this problem.

Use ProcessBuilder and supply a directory path
ProcessBuilder pb = new ProcessBuilder(
"./fs_cli",
"-x",
"originate loopback/1234/default &bridge(sofia/internal/1789#192.168.0.198)");
pb.directory(new File("..."));
Process pr = pb.start();
BufferedReader br = new BufferedReader(new InputStreamReader(pr.getInputStream()));
String str = null;
while ((str = br.readLine()) != null) {
System.out.println(str);
}
Where possible, you should provide the command arguments as separate Strings, this will pass each as a separate argument to the process and take care of those arguments that need to be escaped by quotes for you (unless it's expecting the quotes, then you should include them anyway)

The other way is:
ProcessBuilder processBuilder = new ProcessBuilder( "/bin/bash", "-c", "cd /usr/local/freeswitch/bin && ./fs_cli -x \"originate loopback/1234/default &bridge(sofia/internal/1789)\"" );
processBuilder.start();

How to perform a shell redirection (command > output.txt) using ProcessBuilder?

I wanted to backup a MySQL database using ProcessBuilder and the > character is not being interpreted as I expected. This is my code:
java.util.List<String> cmd = new java.util.ArrayList<>();
cmd.add("mysqldump");
cmd.add("-u");
cmd.add("root");
cmd.add("-p"+password);
cmd.add("DBx");
cmd.add(">");
cmd.add("DBbk.sql");
ProcessBuilder pb = new ProcessBuilder(cmd);
pb.directory(new File("."));
Process p = pb.start();
p.waitFor();
BufferedReader err = new BufferedReader(new InputStreamReader(p.getErrorStream()));
while((line = err.readLine()) != null) {
System.out.println(line);
}
The output is:
Warning: Using a password on the command line interface can be insecure.
mysqldump: Couldn't find table: ">"

The process builder is executing the program directly, not executing it through a shell/command prompt. Therefore, you don't get any nice features of the shell like the > character for redirection. Sorry.

Give this a try (just displaying the significant portion of the solution):
new ProcessBuilder("cmd", "/C", "your_command > DBbk.sql").start()
This way you're explicitly calling cmd. In Linux you could call bash or whatever shell you use.

java Processbuilder - exec a file which is not in path on OS X

Okay i'm trying to make ChucK available in exported Processing sketches, i.e. if i export an app from Processing, the ChucK VM binary will be executed from inside the app. So as a user of said app you don't need to worry about ChucK being in your path at all.
Right now i'm generating and executing a bash script file, but this way i don't get any console output from ChucK back into Processing:
#!/bin/bash
cd "[to where the Chuck executable is located]"
./chuck --kill
killall chuck # just to make sure
./chuck chuckScript1.ck cuckScriptn.ck
then
Process p = Runtime.getRuntime().exec("chmod 777 "+scriptPath);
p = Runtime.getRuntime().exec(scriptPath);
This works but i want to run ChucK directly from Processing instead, but can't get it to execute:
String chuckPath = "[folder in which the chuck executable is located]"
ProcessBuilder builder = new ProcessBuilder
(chuckPath+"/chuck", "test.ck");
final Process process = builder.start();
InputStream is = process.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String line;
while((line = br.readLine()) != null) println(line);
println("done chuckin'! exitValue: " + process.exitValue());
Sorry if this is newbie style :D

ProcessBuilder builder = new ProcessBuilder
(chuckPath+"/chuck", chuckPath+"/test.ck");
the args all need an absolute path.

CMD.exe command in java not terminating

I'm trying to use cmd.exe to search for a file in a specific directory and then display the path in a java program and write it to a file. The problem is that the process never terminates.
Here is my code:
String[] str = new String[] { "cmd.exe ", "cd c:\\",
" dir /b /s documents", "2>&1" };
Runtime rt = Runtime.getRuntime();
try{
Process p = rt.exec(str);
InputStream is =p.getInputStream();
InputStreamReader in = new InputStreamReader(is);
StringBuffer sb = new StringBuffer();
BufferedReader buff = new BufferedReader(in);
String line = buff.readLine();
while( line != null )
{
sb.append(line + "\n");
line = buff.readLine();
}
System.out.println( sb );
File f = new File("test.txt");
FileOutputStream fos = new FileOutputStream(f);
fos.write(sb.toString().getBytes());
fos.close();
}catch( Exception ex )
{
ex.printStackTrace();
}

Please try
cmd /c
instead of simply
cmd
Reference

Runtime.exec doesn't work that way. You can't pass multiple commands like that to cmd.exe.
Runtime.exec allows you to execute a single process with a list of arguments. It does not provide any "shell" operations (like 2>&1 for instance). You must do that sort of IO redirection yourself using the Input/Output streams.
It's similar to calling another program's main function.
You could try `Runtime.exec( new String[] { "cmd.exe", "/c", "dir", "C:\\" } );
But realistically, if you want file listings, you're much better off using the facilities in the java.io.File class, which won't depend on operating system specific features.

why are not using Java to do directory traversal instead of calling external shell command? It makes your code not portable!

You must use the start command in addition to the cmd.exe process with the /C or /K switch BEFORE the start command. Example: to convert the Windows's command interpreter in a bash console (from the mingw prroject) you must invoke the exec method of the Runtime class with the command "C:\Windows\System32\cmd.exe /C start C:\mingw\msys\1.0\bin\bash.exe" (I use an external command rather than an internal because it's more signifiant but you can use internal command like DIR and so on).