I am trying to accomplish two things:
I am running cygwin on Windows7 to execute my unix shell commands and I need to automate the process by writing a Java app. I already know how to use the windows shell through Java using the 'Process class' and Runtime.getRuntime().exec("cmd /c dir"). I need to be able to do the same with unix commands: i.e.: ls -la and so forth. What should I look into?
Is there a way to remember a shell's state?
explanation: when I use: Runtime.getRuntime().exec("cmd /c dir"), I always get a listing of my home directory. If I do Runtime.getRuntime().exec("cmd /c cd <some-folder>") and then do Runtime.getRuntime().exec("cmd /c dir") again, I will still get the listing of my home folder. Is there a way to tell the process to remember its state, like a regular shell would?
It seems that the bash command line proposed by Paŭlo does not work:
C:\cygwin\bin>bash -c ls -la
-la: ls: command not found
I am having trouble figuring out the technicalities.
This is my code:
p = Runtime.getRuntime().exec("C:\\cygwin\\bin\\bash.exe -c ls -la");
reader2 = new BufferedReader(new InputStreamReader(p.getInputStream()));
line = reader2.readLine();
line ends up having a null value.
I added this to my .bash_profile:
#BASH
export BASH_HOME=/cygdrive/c/cygwin
export PATH=$BASH_HOME/bin:$PATH
I added the following as well:
System Properties -> advanced -> Environment variables -> user variebales -> variable: BASH, value: c:\cygwin\bin
Still nothing...
However, if I execute this instead, it works!
p = Runtime.getRuntime().exec("c:\\cygwin\\bin\\ls -la ~/\"Eclipse_Workspace/RenameScript/files copy\"");
1. Calling unix commands:
You simply need to call your unix shell (e.g. the bash delivered with cygwin) instead of cmd.
bash -c "ls -la"
should do. Of course, if your command is an external program, you could simply call it directly:
ls -la
When starting this from Java, it is best to use the variant which takes a string array, as then
you don't have Java let it parse to see where the arguments start and stop:
Process p =
Runtime.getRuntime().exec(new String[]{"C:\\cygwin\\bin\\bash.exe",
"-c", "ls -la"},
new String[]{"PATH=/cygdrive/c/cygwin/bin"});
The error message in your example (ls: command not found) seems to show that your bash can't find the ls command. Maybe you need to put it into the PATH variable (see above for a way to do this from Java).
Maybe instead of /cygdrive/c/cygwin/bin, the right directory name would be /usr/bin.
(Everything is a bit complicated here by having to bridge between Unix and Windows
conventions everywhere.)
The simple ls command can be called like this:
Process p = Runtime.getRuntime().exec(new String[]{"C:\\cygwin\\bin\\ls.exe", "-la"});
2. Invoking multiple commands:
There are basically two ways of invoking multiple commands in one shell:
passing them all at once to the shell; or
passing them interactively to the shell.
For the first way, simply give multiple commands as argument to the -c option, separated by ; or \n (a newline), like this:
bash -c "cd /bin/ ; ls -la"
or from Java (adapting the example above):
Process p =
Runtime.getRuntime().exec(new String[]{"C:\\cygwin\\bin\\bash.exe",
"-c", "cd /bin/; ls -la"},
new String[]{"PATH=/cygdrive/c/cygwin/bin"});
Here the shell will parse the command line as, and execute it as a script. If it contains multiple commands, they will all be executed, if the shell does not somehow exit before for some reason (like an exit command). (I'm not sure if the Windows cmd does work in a similar way. Please test and report.)
Instead of passing the bash (or cmd or whatever shell you are using) the commands on the
command line, you can pass them via the Process' input stream.
A shell started in "input mode" (e.g. one which got neither the -c option nor a shell script file argument) will read input from the stream, and interpret the first line as a command (or several ones).
Then it will execute this command. The command itself might read more input from the stream, if it wants.
Then the shell will read the next line, interpret it as a command, and execute.
(In some cases the shell has to read more than one line, for example for long strings or composed commands like if or loops.)
This will go on until either the end of the stream (e.g. stream.close() at your side) or executing an explicit exit command (or some other reasons to exit).
Here would be an example for this:
Process p = Runtime.getRuntime().exec(new String[]{"C:\\cygwin\\bin\\bash.exe", "-s"});
InputStream outStream = p.getInputStream(); // normal output of the shell
InputStream errStream = p.getInputStream(); // error output of the shell
// TODO: start separate threads to read these streams
PrintStream ps = new PrintStream(p.getOutputStream());
ps.println("cd /bin/");
ps.println("ls -la");
ps.println("exit");
ps.close();
You do not need cygwin here. There are several pure Java libraries implementing SSH protocol. Use them. BTW they will solve your second problem. You will open session and execute command withing the same session, so the shell state will be preserved automatically.
One example would be JSch.
Related
I had a Java program running a shell script with a Process, but for some reason when I try to run it it throws an error open terminal failed: missing or unsuitable terminal: unknown. From other SO questions, I think this is a tmux problem, but I'm not really sure how to solve it. Here's the code calling the script:
ProcessBuilder pb = new ProcessBuilder("/Users/user/eclipse-workspace/project/start.sh");
Process p = pb.start();
BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream()));
System.out.println("output: ");
String s;
while ((s = stdInput.readLine()) != null) {
System.out.println(s);
}
And here's the shell script:
#! /bin/sh
ssh -tt -i ~/.ssh/ssh-key.key opc#___._.___.___ tmux attach -d << END
./run.sh
END
exit 0
I have tried running the script from terminal, and it works from the terminal but it doesn't work when I run the Java program.
The problem is that you are attaching to an interactive tmux session, where you need to have a terminal which supports cursor movement codes etc.
The easy workaround is to not attach; just submit the command you want to run into the session.
ssh -tt -i ~/.ssh/ssh-key.key opc#___._.___.___ tmux send-keys './run' C-m
This obviously requires that whatever is running inside the remote tmux session is in a state where you can submit a shell command, i.e. at a shell prompt or similar. For robustness you might want to take additional measures to make sure this is always the case, or refactor your solution to avoid running inside tmux e.g. by having the command redirect its output to a file where you can examine it from any terminal at any time (though this assumes you don't also need to interact with it subsequently).
I'm having the next error when execute a cmd command using Java. I'm working in a mac laptop. This is my code:
private static String exportContainerFromImage(String container) {
//docker export mysql_dummy > ~/Documents/mysql_dummy.tar
String errorMessage = "";
String[] cmdArgs =
{"docker export mysql_dummy > ~/Documents/mysql_dummy.tar", "bash"};
Process process = Runtime.getRuntime().exec(cmdArgs);
}
But I'm getting the error, error=2, No such file or directory, if I execute the command directly on the terminal it runs successfully, I tried also changing the directory to ~\\Documents\\mysql_dummy.tar and got the same result.
But if I run the command with the arguments:
{"docker create -ti --name mysql_dummy mysql", "bash"};
It runs properly
Any ideas?
You're conflating 'shell magic' with 'an OS'. Also, you seem to be wildly confused about what the array form of cmdArgs does, because you've tagged a bash in there at the end. That array is supposed to contain the executable's full path at arr[0], and all arguments at arr[1] and up. docker create -ti ... is clearly not a filename, and bash is clearly not an argument.
Shell magic?
If you type:
docker create -ti --name mysql_dummy mysql
on the command line, bash (or cmd.exe if on windows, or whatever shell you are using) reads it and does a whole bunch of replacement magic and parsing on this. It's the shell that does this, not the OS, and java's processbuilder stuff is not a shell and therefore isn't going to do all that. What you're attempting to do? Run that entire line as if it's a single file name that is executable which it clearly isn't.
This is all shell magic - all things that you CANNOT do with exec. Fortunately, java is a programming language, so you can do all these things by, well, programming it.
Parsing out params by splitting on whitespace.
quoting to avoid that splitting, but then removing the quotes.
Treating ~ as a ref to a homedir.
Replacing * and ? in filename paths.
Variable substitution
Setting up redirects with > somefile.txt or 2> /dev/null or < file.in or whatnot.
You must do those things.
In addition, exec cannot be used to this, period. As usual, the only non-problematic way to run processes is to always use ProcessBuilder, no exceptions. Consider runtime.exec a known-broken method you must never call.
ProcessBuilder lets you redirect the output.
String[] cmdArgs = {
"/bin/docker" // note, FULL PATH!
"export",
"mysql_dummy"
};
File out = new File(System.getProperty("user.home"), "Documents/mysql_dummy.tar");
ProcessBuilder pb = new ProcessBuilder(cmdArgs);
pb.redirectOutput(new File(out));
pb.start();
That does what you want, presumably.
The alternative is to make a script (script.sh or script.bat) and then start bash or cmd.exe and ask it to run that script.
String[] args = { "/bin/bash", "-c", "/fully/qualified/path/to/the/script.sh" }
and then exec that. Now you can pile *.txt, > foobar.txt, ~/homediref, and all the other shellisms in that script as much as you like.
Overall #rzwiterloot's answer is good, but there are some alternatives it leaves out.
First, what I would consider the best solution to this problem: the -o option to docker export.
"docker", "export", "mysql_dummy", "-o", "Documents/mysql_dummy.tar"
Ignoring ~/ here, this set of command and arguments will achieve the same thing as ... > Documents/mysql_dummy.tar but doesn't rely on the shell for the redirection; docker export is perfectly capable of handling that operation itself.
Second, if you wanted to run a shell command from the program, you could. I would not recommend this. But in certain circumstances it might make sense.
The alternative is to make a script
You don't have to put the command in a separate file. Actually this is one inaccuracy in #rzwiterloot's answer; -c allows you to pass command(s) to bash, not the path to a file containing commands.
"bash", "-c", "docker export mysql_dummy > ~/Documents/mysql_dummy.tar"
However, I'd recommend you avoid invoking shells from any program you write. They're quirky and esoteric and there's almost always a simpler way to achieve what you want, such as docker export's -o optiopn, in this case.
The goal of my program is to run an interactive command line executable from Java, so I can add input partway through when required. Basically redirecting input.
I couldn't find anything that worked online because the -c flag does not allow interactivity, but then I saw that the -i flag in the terminal allowed me to run commands with interactive input if I fed it a .sh file.
However, when I tried using this flag in java, it didn't work. I have separate input and output threads, so if I could get this to work it seems like it would be easy.
Relevant code:
ProcessBuilder pb = new ProcessBuilder()
.directory(new File(testDir))
.inheritIO()
.command("bash", "-i"
,"executor.sh");
proc = pb.start();
this is the error i get:
bash: cannot set terminal process group (1469): Inappropriate ioctl for device
bash: no job control in this shell
If there's way I could get this -i option working, then I'd appreciate pointers to something else that would allow me to get interactive input working because nothing else that I've tried seems to solve this problem.
bash -i is completely unrelated to ability to read from the TTY.
Rather, redirect from the TTY, after your script already started:
#!/usr/bin/env bash
exec </dev/tty || { echo "ERROR: Unable to connect stdin to /dev/tty" >&2; exit 1; }
read -r -p "Fill out this prompt please: " value
echo "Read from TTY: $value"
The command exec </dev/tty replaces the script's stdin (FD 0) with a read handle on /dev/tty. If you wanted to do this just for a single command, rather than for the whole script, put </dev/tty on the end of that command.
Of course, this only works if your process is run in a context where it has a controlling terminal at all -- but if that weren't the case, you couldn't read from the user without getting some kind of handle on an I/O device regardless.
I'm using apache-commons-exec to execute some commands in a Java application.
When I execute 'ls -la /home/user' it works great.
But I need to execute something like this
./setEnvsOfTypeXXX.sh; ./setEnvsOfTypeYYY.sh; ls -la /home/user
I enter the command into the CommandLine object and it doesn't work.
It returns an empty string and -559038737 exit code.
Because the nature of the environment and the scripts (the firsts ones sets some needed environment variables); i can not put all the call into a script o
I've tried many solutions (like surround all the command with quotation marks like "'" or use the PumStreamHandlet input stream) but nothing has worked so far...
Anyone has an idea ?
try
sh -c '. ./setEnvsOfTypeXXX.sh; . ./setEnvsOfTypeYYY.sh; ls -la /home/user'
As your command
Two things I'm guessing you need here.
First if you are setting enviroment variables you probably need to use .
Second you want to run a shell and get the shell to exec the shell scripts and then run the following command, all in the same context
I tried this code
cmdLine = new CommandLine("/bin/bash");
cmdLine.addArgument("-c");
cmdLine.addArgument(new StringBuilder().append("'").append(command).append("'").toString());
And even with command = "ls";
There is an error
bash: ls: No such file or directory
fun fact: in windows this works ok !
cmdLine = new CommandLine("cmd.exe");
cmdLine.addArgument("/c");
cmdLine.addArgument(new StringBuilder().append("\"").append(command).append("\"").toString());
logger.info("Command win line: cmd.exe /c \""+command + "\"");
I totally out of options now !!!
I got a workarround: create a temporal sh file with the command, putting shebang on firts line and giving permissions, executing this file in one command line, get result and output, for last delete temporal file...
and it works !
Runtime.getRuntime().exec(new String[] {
"cmd",
"/c",
"start",
"cd",
"M:\\MandNDrives\\mwallace\\PROPHET\\PROPHET\\Prophet2012"
"prpht0912" //shortcut to prpht0912.exe
"eorinput" // eorinput.ind, input sheet that prpht0912.exe processes
Opens a command prompt to the dir I need.
To execute the program contained in that folder, I then need to execute "prpht0912 eorinput" from the command prompt like:
M:\MandNDrives\mwallace\PROPHET\PROPHET\Prophet2012>prpht0912 eorinput
However the space in the entry returns an error in the prompt: "The system cannot find the path specified"
It isn't possible to execute two commands via the command line in a single invocation of cmd.exe: cmd.exe /c is followed by a single command, and another /c afterwards would be interpreted as a parameter to that command.
Furthermore, invoking it twice won't get you what you want either, as changes of directory are forgotten when the process exits, so the second invocation would be run in the default working directory of the Java process, not the directory you changed to with your first invocation.
Also, it is unfortunate, but Java doesn't provide a way to change the current working directory of its own process.
As far as I can see it, you have two options:
Make sure your Java program is started with the working directory set to the one you need your child program to run in
Invoke a single .bat file that contains both of the commands you need to run.
To Execute the following command
M:\MandNDrives\mwallace\PROPHET\PROPHET\Prophet2012>prpht0912 eorinput
You need the following
String[] commands = new String[] { "cmd", "/c", "M:\\MandNDrives\\mwallace\\PROPHET\\PROPHET\\Prophet2012\\prpht0912.exe eorinput" };
Runtime.getRuntime().exec(commands);
Note**
When you pass an array, ProcessBuilder would consider only the first element as program and remaining as arguments for that program.
String prog = cmdarray[0];