I once tried to quickly hack together some bash using "Copy as curl" in firebug to do something similar and got this shameful monstrosity after a minute or two of fighting with awk:

       for i in {10..14};do for j in 1 7; do date -d "20$i-0$j-01T00:11:20.000Z" "+%s000";date -d "20$i-0$j-01T00:11:20.000Z" "+%s000"|tr "\n" " "; done;done|sed '1d;$d'|awk '{system("curl \047https://maps.google.com/locationhistory/b/0/kml?startTime=" $1 "&endTime=" $2 "\047 -H \047Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\047 -H \047Accept-Encoding: gzip, deflate\047 -H \047Accept-Language: en-US,en;q=0.5\047 -H \047Connection: keep-alive\047 -H \047Cookie:cookie-stuff\047 -H \047Host: maps.google.com\047 -H \047User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:30.0) Gecko/20100101 Firefox/30.0\047 -o " $1 ".kml")}'

(And the above doesn't look quite as bad as what I was doing without the actual cookie data there, so that's saying something.)

At which point I took a few minutes to think deeply about life and what possessed me to write such an obscenity, and decided to use Takeout to get the data instead.

Edit: That's not to say it didn't work, it gave me all the data. It was just a bad way to do it.

Thank you. I also spent a lot of time looking for a programmatic way to access the data after Latitude's demise, and decided that using another app was easier.

You can just use Google Takeout, IIRC.

Takeout does not provide an API.