I have a bash script (.sh file) that puts weather conditions on an image. I am having problems getting the -30 near the end of the string. The text file that I am geting the info from is fairly large but this is the rows of text I am trying to get.

</dd>
<dt>
<a href="http://ec.gc.ca/meteo-weather/default.asp?lang=En&amp;n=5FBF816A-1" title="Wind Chill">Wind Chill</a>:
</dt>
<dd class="mrgn-bttm-0 wxo-metric-hide">-30</dd>
<dd class="mrgn-bttm-0 wxo-imperial-hide wxo-city-hidden">-22</dd>
</dl>



I have tried the following but can't get my head around what I am doing.


This gets the correct file but not the correct data (-30)


windchillStr=$(grep -A30 "Ottawa Macdonald-Cartier Int'l Airport" "$weatherFile" | grep -A1 "Wind Chill" | tail -1)

windchill=$(echo $windchillStr | cut -d ">" -f 2 | cut -d "</dd" -f 1)

Any help would be appreciated.

I might be inclined to some simple sedlook for text, skip down 2 lines, strip out whatever is between > <.
Kiss.

Does make some assumptions about the layout.

Hi

Thanks for the quick Response but that does not find it either ?

winchill=$(sed -nr '/Wind Chill/{n;n;s/.*>(.*)<.*/\1/p}' "$weatherFile")

I have attached the file I am searching

Attached Files

weather_temp_live.txt (51.3 KB, 21 views)

Did you look at what got assigned ?.
There are two matches on that file, which complicates things a little. Not so much if you (always) want the first occurrence.
I might be inclined to use a bash array to hold all the returned fields.

Yes the query didn't pick up anything as it looked at the first occurrence. I had this to find the correct place to start from

windchillStr=$(grep -A30 "Ottawa Macdonald-Cartier Int'l Airport" "$weatherFile")


This pulls up the following text: <dd class="mrgn-bttm-0">Ottawa Macdonald-Cartier Int'l Airport</dd> <dt>Date: </dt>
I tried this but didn't work

windchill=$(sed -nr '/Wind Chill/{n;n;s/.*>(.*)<.*/\1/p}' "$windchillStr")

Very strange - I get two -30 ("-30 -30") assigned to the variable using your file. As it should.

What commands did you run and how do I get just one -30 ??

I used the command I gave you earlier.

Ahhhh - hang on; are you still using windchillStr ?. Don't.
Use my command is place of both - sorry, I should have been clearer about that. As for only one result, which one ?. What about if there are more - 3, 5, 20, ...
Data providers change format ever so often too.

one thought:
if you want to get content from a html page, why don't you use the same logic that is at work inside your browser?
it's called xpath (ok i'm simplifying things here, but just read the intro to the tutorial) and there's a command line utility called "xmllint" (included in a package usually called "libxml2" iirc).

i was using the same sed/grep-logic for my weather script - until i bit the bullet and changed it all to xmllint.

have a look at my weather conky & shell script in my github stuff link below.

I am just using your code and it does not find the Wind Chill Temperature when run on the file I attached. It return nothing at all ?

The file format is pretty static it changed in the summer and uses Humidex instead of Wind Chill but nothing major in the last few years.

I might have to look into this at some time but at 66 learning new things does not come easy

neither does it at 44, with no IT background.

The answer to my problem is below:


I also found that I could use the .xml file instead of the web page text.

In the US, I would never use a webpage to get weather. That's the hard way. It's easy enough to get actual text weather reports from the NWS for any airport which reports weather, and they're easier to parse. But I don't know about the Great White North, things may be very different up there. :-P