Partial code rewriting + history

hncomments.sh

@@ -0,0 +1,58 @@
+#!/bin/bash
+#
+# Requires: jq, recode, sed, curl, mail
+#
+# Copyright (c) 2017 John Graham-Cumming
+
+# Name of file in which to store the timestamp of the last comment downloaded
+f="$HOME/.hnlast"
+
+# The query string to be found in comments (e.g. q="cloudflare")
+q="Cloudflare"
+
+# Email to send found comments to (e.g. e="[email protected]")
+e=""
+
+if [[ -e $f ]]
+then
+  l=$( <$f )
+else
+  l=0
+  touch $f
+fi
+
+j=$( curl -s https://hn.algolia.com/api/v1/search_by_date?query=$q&tags=comment&numericFilters=created_at_i\>$l )
+
+if [[ -z $j ]]
+then
+  # This shouldn't happen.
+  # Even if there is not result, the API returns a JSON object along with the query parameters.
+  # $j is undefined if the server is unreachable.
+  exit
+fi
+
+h=$( jq ' .nbHits ' <( echo $j ) )
+
+if [[ $h -eq 0 ]]
+then
+  # The query result is empty.
+  exit 0
+else
+
+  t=$( jq ' .hits | .[] | .created_at_i ' <( echo $j ) | sort -rn | head -n 1 )
+
+  grep -q $q $f
+
+  if [[ $? -eq 1 ]]
+  then
+    # No entry for this query, create one.
+    echo "$q|$t" >> $f
+  fi
+
+  # We update the existing entry with the latest timestamp
+  grep  $q $f | sed -ie "s/|.*/|$t/g" $f
+  # As mentioned here http://stackoverflow.com/a/12887319,
+  # sed doesn't support case-insensitive matching on OSX.
+fi
+
+jq -r '.hits | .[] | .author + "\nhttps://news.ycombinator.com/item?id=" + .objectID + "\n\n" + .comment_text + "\n\n---\n\n"' <(echo $j) | sed -e 's/<[^>]*>/ /g;' | recode -f html..ascii | mail -s "Latest $q HN comments" $e