Get how many public repositories mention a topic for a list of GitHub topics.

github_topic_count.sh

#! /bin/sh
echo "Counting repositories for GitHub topics ($# given)."
for topic in $@; do
    count=`curl https://github.com/topics/$topic -s | grep Counter | cut -d'>' -f2 | cut -d'<' -f 1`
    printf '%-20s: %-6s repos.\n' $topic $count;
done

Example output:

Counting repositories for given GitHub topics (5 given).
foo                 : 6      repos.
bar                 : 160    repos.
java                : 61,853 repos.
fizzbuzz            : 199    repos.
machine-learning    : 22,131 repos.