commons-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Siegfried Goeschl <siegfried.goes...@it20one.at>
Subject Re: Why execute a ping unavailable address will raise exception?
Date Wed, 07 Nov 2012 08:05:25 GMT
Hi folks,

this works as expected - you start an external application and this 
application returns an exit value.

Under many OS an non-zero exit value is considered as an error code 
hence commons-exec throws an exception (please note that the "good" exit 
values are  OS-specific). So in your use case the behavior is perfectly 
reasonable since "ping NOEXISTINGHOST" does indeed not work properly. If 
you would like to consider certain exit values as success than checkout 
"DefaultExecutor#setExitValue()"

Cheers,

Siegfried Goeschl

On 07.11.12 08:38, Yi Huang wrote:
> I did not use exec for a while but from what I remember, you had better set
> the default exit value. For example, if default exit value is set to 1,
> then exec will return 1 if it think the command is ok. Then your system
> will say there is an error because the system exit value 1 is an error
> while 0 is normal.
>
> Hope that helps somehow.
>
> --Yi Huang
>
> 2012/11/7 nie fei <teclusky@gmail.com>
>
>> I'm a new learner for this API. Sorry for the last mail, my mistake with
>> wrong button.
>>
>> CommandLine cmdLine = CommandLine.parse("ping 10.80.41.171 -n 1");
>>
>>          ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
>>          DefaultExecutor exec = new DefaultExecutor();
>>          PumpStreamHandler streamHandler = new PumpStreamHandler(
>> outputStream);
>>          exec.setStreamHandler(streamHandler);
>>          exec.execute(cmdLine);
>>          System.out.println(outputStream.toString());
>>
>>
>> Normally, if the address is available, then there will be no exception
>> raised. Otherwise, the exec.execute(cmdLine) will raise exception:
>>
>> Process exited with an error: 1 (Exit value: 1)
>>
>> Is it normal? Can anyone explain why?
>>
>
>


---------------------------------------------------------------------
To unsubscribe, e-mail: user-unsubscribe@commons.apache.org
For additional commands, e-mail: user-help@commons.apache.org


Mime
View raw message