Rewrite mklesskey to fix #13

bollux

@@ -1181,31 +1181,66 @@ less_prompt_escape() { # less_prompt_escape STRING
 	printf '\n'
 }
 
-# generate a lesskey(1) file for custom keybinds
+## Generate a lesskey(1) file for custom keybinds
+# After less 582, less itself can read lesskey configuration files, rendering
+# the lesskey *program* deprecated.  The exact message is, apparently, this:
+#
+#    NOTE: lesskey is deprecated.
+#         It is no longer necessary to run lesskey,
+#         when using less version 582 and later.
+#
+# Now I don't have less 582 available on my machine (Debian of course!), so I'm
+# relying on a report from 'bencollver' on tildegit.  (Thanks for the report,
+# ben!)
+#
+# That being said, this may not work.  *Please test!* --- acdw 2022-08-09
 mklesskey() { # mklesskey
 	if [[ -f "$BOLLUX_CUSTOM_LESSKEY" ]]; then
 		log d "Using custom lesskey: '$BOLLUX_CUSTOM_LESSKEY'"
 		BOLLUX_LESSKEY="${BOLLUX_CUSTOM_LESSKEY}"
-	elif [[ -f "$BOLLUX_LESSKEY" ]]; then
-		log d "Found lesskey: '$BOLLUX_LESSKEY'"
+		return
+	fi
+
+	less_version="$(less --version | awk '{print $2;exit;}')"
+	lesskey_ft="$(file -i "$BOLUX_LESSKEY")"
+	lesskey_make=false
+
+	if [[ "$lesskey_ft" =~ .*application.* && less_version -lt 582 ]] ||
+		[[ "$lesskey_ft" =~ .*text.* && less_version -ge 582 ]]; then
+		mv "$BOLLUX_LESSKEY" "${BOLLUX_LESSKEY}.bak"
+		log e "Moved incompatible lesskey '$BOLLUX_LESSKEY' to '${BOLLUX_LESSKEY}.bak'."
+		lesskey_make=true
+	fi
+
+	if [[ ! -f "$BOLLUX_LESSKEY" ]]; then
+		lesskey_make=true
+	fi
+
+	if "$lesskey_make"; then
+		log d "Generating lesskey..."
+		cat >/tmp/bollux_lesskey <<-EOF
+			#command
+			${KEY_OPEN} quit 0 # 48 open a link
+			${KEY_GOTO} quit 1 # 49 goto a url
+			${KEY_BACK} quit 2 # 50 back
+			${KEY_FORWARD} quit 3 # 51 forward
+			${KEY_REFRESH} quit 4 # 52 re-request / download
+			${KEY_GOTO_FROM} quit 5 # 53 goto a url (pre-filled)
+			${KEY_CYCLE_PRE} quit 6 # 54 cycle T_PRE_DISPLAY and refresh
+			# other keybinds
+			\\40 forw-screen-force
+			h left-scroll
+			l right-scroll
+			? status   # 'status' will show a little help thing.
+			= noaction
+		EOF
+		if ((less_version >= 582)); then
+			mv /tmp/bollux_lesskey "$BOLLUX_LESSKEY"
+		else
+			lesskey -o "$BOLLUX_LESSKEY" /tmp/bollux_lesskey
+		fi
 	else
-		log d "Generating lesskey: '$BOLLUX_LESSKEY'"
-		lesskey -o "$BOLLUX_LESSKEY" - <<END
-#command
-${KEY_OPEN} quit 0 # 48 open a link
-${KEY_GOTO} quit 1 # 49 goto a url
-${KEY_BACK} quit 2 # 50 back
-${KEY_FORWARD} quit 3 # 51 forward
-${KEY_REFRESH} quit 4 # 52 re-request / download
-${KEY_GOTO_FROM} quit 5 # 53 goto a url (pre-filled)
-${KEY_CYCLE_PRE} quit 6 # 54 cycle T_PRE_DISPLAY and refresh
-# other keybinds
-\\40 forw-screen-force
-h left-scroll
-l right-scroll
-? status   # 'status' will show a little help thing.
-= noaction
-END
+		log d "Lesskey found: $BOLLUX_LESSKEY"
 	fi
 }