[sane-devel] PIXMA TS8300 Series not working

[Alexander Pevzner]

On 10/7/20 11:29 PM, Till Kamppeter wrote:
> Alex, you could suppress the stderr output of libxml.
> 
> Enclose the call of the libxml function(s) with the following code:

Till, it will affect all threads of the calling process, which is not 
very good.

> ----------
>    int fd1, fd2;
> 
>    /* Eliminate any output to stderr, to get rid of the error
>       message output of the functions of libxml */
>    fd1 = dup(2);
>    fd2 = open("/dev/null", O_WRONLY);
>    dup2(fd2, 2);
>    close(fd2);
> 
>    /* Put any code using functions of libxml here: */
>    ...
> 
>    /* Re-activate stderr output */
>    dup2(fd1, 2);
>    close(fd1);
> ----------
> 
> This redirects the stderr into /dev/null. After you are done with the 
> libxml funxtions you can return to normal behavior, if you actually need 
> to output something to stderr later.
> 
> Alternatively, you could use the receiving end of a pipe instead of fd2 
> in the "dup2(fd2, 2)" if you want to capture libxml's stderr output (you 
> would need to fork() before to create a process for receiving the stderr 
> output, which reads the other end of the pipe).
> 
>     Till
> 
> 
> On 07/10/2020 21:55, Alexander Pevzner wrote:
>> On 10/7/20 10:39 PM, Yoann Le Montagner wrote:
>>> Please find the log for 'SANE_DEBUG_AIRSCAN=1 scanimage -L' in 
>>> attachment.
>>
>> Now I see. sane-airscan discovers some IPP device "bbox Ippos Printer" 
>> with the address 192.168.1.254 and attempts to check it for WSD 
>> support. It does it by sending some HTTP request to that address. This 
>> request is redirected to https://mabbox.bytel.fr:443/login.html and 
>> response from there is not valid XML, so XML parser complains.
>>
>> Unfortunately, libxml complains directly to stderr, and it cannot be 
>> silenced.
>>
>> So this problem is cosmetical, though annoying.
>>
>>> Thanks for your work.
>>>
>>> Le 07/10/2020 à 21:35, Alexander Pevzner a écrit :
>>>> On 10/7/20 10:29 PM, Yoann Le Montagner wrote:
>>>>> The parser error is always there.
>>>>
>>>> Please, rerun scanimage with the following options:
>>>>
>>>> SANE_DEBUG_AIRSCAN=1 scanimage -L
>>>>
>>>>> Le 07/10/2020 à 21:27, Alexander Pevzner a écrit :
>>>>>> Hi Yoann,
>>>>>>
>>>>>> On 10/7/20 6:38 PM, Yoann Le Montagner wrote:
>>>>>>> 1) Start the PC
>>>>>>> 2) scanimage -L -> OK, both drivers are here:
>>>>>>>
>>>>>>> yoann at yoann-desktop:~$ scanimage -L
>>>>>>> Entity: line 1: parser error : Start tag expected, '<' not found
>>>>>>> �
>>>>>>> ^
>>>>>> Do you see this "parser error" message every time you call 
>>>>>> "scamimage -L", or it is hard to reproduce?
>>>>>>
>>>>>> If you can reproduce this message, I want to better investigate it.
>>>>>>
>>>>
>>>>
>>
>>


-- 

	Wishes, Alexander Pevzner (pzz at apevzner.com)