Runtime.exec() is not parsing properly when a argument contains space

It is the shell that interprets escaping so you need

String[] command = {"sh","-c","YourExecutable hai \"how r u\""};

Process p = Runtime.exec(command);

or you can use

String[] command = {"YourExecutable", "hai", "how r u"};

Process p = Runtime.exec(command);

Message was edited by:

sabre150

sabre150a at 2007-7-12 9:59:04 >

> Use the exec(String[]) method instead of the

> exec(String) method.

>

> Edit: Man, am I slow. And (partially) wrong.

No. You are right if you don't try to specify escaping. By specifying the arguments as separate elements of the array, no escaping is required.

sabre150a at 2007-7-12 9:59:04 >

> folks thanks for your reply..

>

> But I think will not solve my problem. These things

> will surely work, but our customer have this running

> in the their work place and facing this problem only

> in solaris and not in windows.. so we can fix this in

> the next release.. but want could be the solution now

> !

You could prefix the command with "sh -c " so that the shell is active once again but on some shells this does not work. Must be worth a try.

>

> We need to give a reply to them, saying whether it is

> our bug or a problem in Java API since it's working

> fine in Windows.

Behind the scenes, Windows (or really DOS) has created frigged version of the Unix 'C' exec() calls library so that they behave similar but not the same a the Unix version. I suspect Java just uses this library.

>

> Question : Why passing whole command with argument as

> a single works in windows and not in solaris/unix ?

> Can I conclude and say this is due to a bug in Java

> API?

Definitely NOT.

Edit : I have been racking my brains and I think you need the command string to be

"sh -c \"YourExecutable hai \"how r u\"\""

because the -c option says treat the next argument as a command to the shell.

Message was edited by:

sabre150

sabre150a at 2007-7-12 9:59:04 >

>> As single quotes should work just well for the shell

>> as the double quotes.

>

> Single quotes have different meaning when it comes to

> the expansion of environment variables.

True, but if it is only to provide an argument (that does not contain any kind of variable that the shell should interpret) that contains spaces, it would work, and simplify the escaping. (assuming, of course, that you can get the single string version to work at all).

I made that statement on the assumption that shell variables would not be included in the (inner) quoted string.

Then again, you know what they about the word assume.

;-)

masijade.a at 2007-7-12 9:59:04 >

> using sh -c doesn't seem to work....

It does for me so you are using it wrong.

>

> This is what's happening..

> we give a input box to the user to type the

> executable (user may include arguments to that also..

> ) , and we simply use

> Runtime.getRuntime().exec(txt.getValue());

So where is "sh -c" involved here?

sabre150a at 2007-7-12 9:59:04 >

> Ok, let me give u more details..

As I said in reply #7, I don't know how to use "sh -c command" as a single string. I do know and understand how to use it as String[] command = {"sh","-c","command"};

You said in one post that you can't modify you code but I suspect that if you don't supply an update to your customer then you will loose him.

sabre150a at 2007-7-21 21:13:01 >

> > Ok, let me give u more details..

>

> As I said in reply #7, I don't know how to use "sh -c

> command" as a single string. I do know and understand

> how to use it as String[] command =

> {"sh","-c","command"};

>

exec("sh -c '/bin/ls a b c'");

works, but if you need to escape or quote something in the arg list, it gets hairy.

Edit....

Actually, not that bad.

exec("sh -c '/bin/ls a b \"c d e\"'");

lists

a

b

c d e

Message was edited by:

jverd

jverda at 2007-7-21 21:13:01 >

> are you sure that worked for you?

>

> it doesn't work for me...

>

> bash-2.05# sh -c './a.out a b c \"asdf asd\"'

> bash-2.05# cat data.txt

> ./a.out

> a

> b

> c

> "asdf

> asd"

> bash-2.05#

>

> even directly trying to execute it on the shell

> doesn't work ...

Look, when you execute it in the Runtime.exec() call, the \" will be interpreted by Java to be a simple quote. Your

sh -c './a.out a b c \"asdf asd\"'

will become

sh -c './a.out a b c "asdf asd"'

once interpreted and passed to the shell. Try running that one.

kevjavaa at 2007-7-21 21:13:01 >

> ok, sorry for that.. I should n't have given \" when

> executing in shell.. really sorry..

>

> but when I do the same from runtime.exec().. it

> doesn't work...

>

> watch me..

> > Runtime.getRuntime().exec("sh -c './a.out a b c \"x y

> z\" ' ");

>

>

> argument to shell will be './a.out a b c "x y z" '

No, it will be

./a.out a b c "x y z"

without the 'single quotes' around the whole thing.

> but still I couldn't get the output I want..

What did you get?

The exact command I ran was Runtime.getRuntime().exec("C:/cygwin/bin/sh -c 'ls -l /tmp / > \"/tmp/zzz www\"'");

and it did exactly what I'd expect, the same as

ls -l /tmp / > "/tmp/zzz www"

in a terminal window. It put the results of the ls in a file in /tmp called zzz www.

jverda at 2007-7-21 21:13:01 >

> Can we file a bug for this?

I don't think so! I think it is most probably a feature of the underlying 'C' exec() call.

>

> if it is not possible to make it work a single

> string, I will have to take array approach..

In my view the best solution. The user should be able to specify ALL the elements of the array, not just the command to be executes with the shell. You could easily create a simple language that would allow you to specify the array elements. Regular expressions are your friend.

>

> now I have this question:

>

> 1. what will have if the machine doesn't have bourne

> shell (assuming I use sh -c command to execute)

bsh, bash, csh and tcsh ALL have the -c option. I'm not sure about ksh. It is normal for /bin/sh to be linked to one of the shells.

> 2. How to find the default shell in solaris? If

> something like a system variable which will give me

> the default shell, so that I can use it to execute

> the script be sure that it exist in the mahine..

When one adds a user one specifies which shell he should use.

Instead of using String[] command = {"sh","-c","......."}; you can explicitly use a particular shell. For example String[] command = {"csh","-c","......."}; . If I had to allow my users to specify a command for Runtime.exec() I would create a syntax that would let the user define which shell is being used and the option that defines the script location. I consider it a VERY VERY dangerous approach and would try to find some way round using it.

sabre150a at 2007-7-21 21:13:02 >