[sane-devel] All sane frontends segfault with my HP 5200C

[Douglas Gilbert]

abel deuring wrote:

> Henning Meier-Geinitz wrote:
> 
>>Hi,
>>
>>On Sun, Feb 03, 2002 at 12:10:10PM +0100, Oliver Rauch wrote:
>>
>>>I think we could and should create a function
>>>sanei_identify_device(char *device_file)
>>>
>>>that has some
>>>#IFDEF _LINUX_
>>>test for major/minor number for SCSI/USB/PARALLEL/...
>>>#...
>>>
>>That's a good idea. I propose a little change:
>>
>>Add something like sanei_scsi_is_scsi, sanei_scsi_is_usb etc to the
>>respective sanei files so we don't have to link every backend to yet
>>another file. So the sanei_usb_open etc. functions would test on their
>>own.
>>
>>Maybe something like
>>
>>SANE_Status
>>sanei_scsi_is_scsi (SANE_String_Const device_file) /* or (int fd) */
>>{
>>#if USE == LINUX_INTERFACE /* is this enough or must we check for __linux__ */
>>  /* get major and minor number */
>>  if (major_minor_is_in_range)
>>    return SANE_STATUS_GOOD;
>>  else
>>    return SANE_STATUS_INVAL;
>>#else
>>  return SANE_STATUS_UNSUPPORTED;
>>#endif
>>}
>>
>>How can I get the major/minor number of a device file?
>>
> 
> Something like
> 
> #include <sys/types.h>
> #include <sys/stat.h>
> 
> stat fileinfo;
> 
> stat(filename, &fileinfo);
> 
> if (S_ISCHR(fileinfo.st_mode) && major(fileinfo.st_rdev) == 21) {
> 	/* SG device file found */
> }
> 
> This is just written down -- not tested! (Don't know, if or where a
> macro definition for the major number 21 exists.)


Abel,
SCSI_GENERIC_MAJOR is defined in <linux/major.h> .
These are also defined in there:
     #define USB_ACM_MAJOR           166
     #define USB_ACM_AUX_MAJOR       167
     #define USB_CHAR_MAJOR          180
and
     #define LP_MAJOR        6


Doug Gilbert