dtrace discuss - Sep 2011 - quotes in command arguments (pid provider)

Hi all,

Sorry for a beginner''s question but I can''t find the answer
anywhere and
do not have time to investigate so I decided to exploit this forum. Is 
there a way how to instrument a command which has arguments containing 
whitespace with PID provider ?

I am doing something like this:

dtrace -Z -n ''pid$target::myfunc:return/arg1 == 1/ { ustack();
}'' -c
"/usr/bin/mycmd -a \"foo bar\" -b another"

but everything I tried lead to usage printed by the command or dtrace(1) 
for one reason or another.

Thanks for the answers,


v.

I''ve not tested this but can you try  adding an escape char ( \ )
before the $target as well. Shell can do bad things to it.

So something like?

dtrace -Z -n ''pid\$target::myfunc:return/arg1 == 1/ { ustack();
}'' -c "/usr/bin/mycmd -a \"foo bar\" -b another"

-Angelo


On Sep 1, 2011, at 9:00 AM, Vladimir Kotal wrote:
> 
> Hi all,
> 
> Sorry for a beginner''s question but I can''t find the
answer anywhere and do not have time to investigate so I decided to exploit this
forum. Is there a way how to instrument a command which has arguments containing
whitespace with PID provider ?
> 
> I am doing something like this:
> 
> dtrace -Z -n ''pid$target::myfunc:return/arg1 == 1/ { ustack();
}'' -c "/usr/bin/mycmd -a \"foo bar\" -b another"
> 
> but everything I tried lead to usage printed by the command or dtrace(1)
for one reason or another.
> 
> Thanks for the answers,
> 
> 
> v.
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org

Hey Vladimir,

This is a bug in the way that DTrace composes arguments to the command
it executes as a result of the -c option.

http://src.illumos.org/source/xref/illumos-gate/usr/src/cmd/dtrace/dtrace.c#274

You can see that make_argv() just tokenizes the string based on
whitespace -- it doesn''t use the tokenizing logic that the shell would
use. dtrace(1M) should probably do something like libast`sfnew() of
the command string, followed by an libshell`sh_parse() and
libshell`sh_exec() -- i.e. we want dtrace -c to act like sh -c.

I''ve filed this bug to track the issue:

  https://www.illumos.org/issues/1440

To work around this, you can probably create a shell script that
simply does an exec of the command you want to run with the arguments
you want.

Adam

On Thu, Sep 1, 2011 at 1:00 PM, Vladimir Kotal
<vladimir.kotal at oracle.com> wrote:
>
> Hi all,
>
> Sorry for a beginner''s question but I can''t find the
answer anywhere and do
> not have time to investigate so I decided to exploit this forum. Is there a
> way how to instrument a command which has arguments containing whitespace
> with PID provider ?
>
> I am doing something like this:
>
> dtrace -Z -n ''pid$target::myfunc:return/arg1 == 1/ { ustack();
}'' -c
> "/usr/bin/mycmd -a \"foo bar\" -b another"
>
> but everything I tried lead to usage printed by the command or dtrace(1)
for
> one reason or another.
>
> Thanks for the answers,
>
>
> v.
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org
>


-- 
Adam Leventhal, Delphix
http://dtrace.org/blogs/ahl

275 Middlefield Road, Suite 50
Menlo Park, CA 94025
http://www.delphix.com

On 09/01/11 18:13, Adam Leventhal wrote:
> Hey Vladimir,
>
> This is a bug in the way that DTrace composes arguments to the command
> it executes as a result of the -c option.
>
>
http://src.illumos.org/source/xref/illumos-gate/usr/src/cmd/dtrace/dtrace.c#274
Oh, it''s using strtok() with "\f\n\r\t\v " as separators.
> You can see that make_argv() just tokenizes the string based on
> whitespace -- it doesn''t use the tokenizing logic that the shell
would
> use. dtrace(1M) should probably do something like libast`sfnew() of
> the command string, followed by an libshell`sh_parse() and
> libshell`sh_exec() -- i.e. we want dtrace -c to act like sh -c.
>
> I''ve filed this bug to track the issue:
>
>    https://www.illumos.org/issues/1440
I filed similar bug in Bugster :)
> To work around this, you can probably create a shell script that
> simply does an exec of the command you want to run with the arguments
> you want.
Works fine, thanks.


v.