On 03/19/2021 03:25 PM, Leon Fauster via CentOS wrote:
> Am 19.03.21 um 17:40 schrieb Fabian Arrotin:
>> On 18/03/2021 22:08, H wrote:
>>> On 03/18/2021 04:30 PM, Paul Heinlein wrote:
>>>> On Thu, 18 Mar 2021, H wrote:
>>>>
>>>>> I have a challenge I am interested in getting feedback on.
>>>>>
>>>>> I will on a regular basis download a series of data files from the web where the data is in XML-format. The format is known in advance but is different between the various data files. I then plan to extract the various data items ("elements?") from each data file, do some light formatting and then save desired parts of each original data file as a formatted CSV-file for later importing into a database.
>>>>>
>>>>> As the plan is to use a bash shell script using curl to get the files, I have begun looking at external XML parsers that I can call from my script, perhaps specify which elements I want, get the data back in some kind of bash data structure and finally format and save as CSV-files.
>>>>>
>>>>> There seems to be a number of XML parsers available but perhaps someone on the list has a recommendation for which one might suit my needs best? I should add that I am running CentOS 7.
>>>>
>>>> Will you be using an XSLT stylesheet to do the work? There's a somewhat steep learning curve, but in my experience it's the most reliable method for parsing XML except in the very simplest of cases.
>>>>
>>>> In that case, the libxslt stuff may be what you want:
>>>>
>>>> http://xmlsoft.org/libxslt/
>>>>
>>>> The command-line tool is xsltproc.
>>>>
>>>> Again, it's not easy to use, but once you've built a toolchain, it will be reliable and fairly easy to modify if the source XML schema change.
>>>>
>>> I just checked and I cannot see that the organization publishing these data files offer any XSLT stylesheet. IOW, I am, perhaps incorrectly, assuming that the publisher of the data would be one with said stylesheet. (Although perhaps that is something an end-user could put together as well??)
>>>
>>> Although the data format of each data series is unique, it is simple and could conceivably be parsed using grep but I am looking for a more "forward-looking" solution for other applications in the future.
>>>
>>> If XSLT stylesheets are not available - would you suggest another tool? Or, would you suggest I design sheets, presumably one for for each data series?
>>>
>>
>> I used in the past xmlstarlet (available in epel) for quick parsing from
>> within bash scripts.
>> For something more robust, maybe switch to python ? (ymmv)
>>
>
>
>
> just for a value grep use xmllint (its in libxml2 package):
>
> Example:
>
> XML input:
>
> <?xml version="1.0" encoding="utf-8" ?><methodResponse><params><param><value><string>OK</string></value></param></params></methodResponse>
>
>
> bash var:
>
> STATUS=$(echo ${RESPONSE} | xmllint --format --xpath "//methodResponse/params/param/value/string/text()" - 2>/dev/null)
>
>
> --
> Leon
>
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> https://lists.centos.org/mailman/listinfo/centos
Thank you, I decided to put together an XSLT stylesheet for each data file format, I think this might be the best for the future.