grep -i url='*' file.url | cut -b 5- | xargs firefox
Extract urls from a *.url file and open in Firefox. (Note that *.url files in Windows are basically just text files, so they can be parsed with a few commands.)
grep extracts lines starting with url=-i flag is to ignore casecut extracts the range of characters from the 5th until the end of linesxargs calls Firefox with arguments taken from the output of the pipelinefirefox $(grep -i ^url='*' file.url | cut -b 5-)