1 files changed, 150 insertions, 0 deletions
diff --git a/bin/rfc b/bin/rfc
new file mode 100755
index 0000000..9c71ebc
--- /dev/null
+++ b/bin/rfc
@@ -0,0 +1,150 @@
+#!/bin/sh
+set -eu
+
+D="${XDG_DATA_HOME:-$HOME/.local/share}/doc/rfc"
+PROMPT_DB="$(
+	cat <<-EOF
+		RFC directory does not exist:
+		  $D/
+
+		Do you want to download the files to create it?
+	EOF
+)"
+
+usage() {
+	cat <<-'EOF'
+		Usage:
+		  rfc [-w] RFC_NUMBER
+		  rfc -u
+		  rfc -h
+	EOF
+}
+
+help() {
+	cat <<-'EOF'
+
+		Options:
+		  -w            show the path to the RFC file instead of displaying
+		                its contents
+		  -u            update the local RFC database
+		  -h, --help    show this message
+
+		Lookup the given RFC
+		in $XDG_DATA_HOME/doc/rfc/ (defaults to ~/.local/share),
+		and feed it into the $PAGER, akin to doing:
+
+		  $ $PAGER $XDG_DATA_HOME/doc/rfc/rfc$RFC_NUMBER.txt
+
+		If the $XDG_DATA_HOME/doc/rfc/ directory doesn't exist, it gets
+		created it by downloading the latest RFC files and placing all .txt
+		files there.
+
+
+		Examples:
+
+
+		  Show RFC 1234 in $PAGER:
+
+		    $ rfc 1234
+
+
+		  Print path to RFC 2222:
+
+		    $ rfc 2222
+
+
+		  Download the latest RFCs:
+
+		    $ rfc -u
+	EOF
+}
+
+view() {
+	if [ -t 1 ]; then
+		${PAGER:-cat}
+	else
+		cat
+	fi
+}
+
+update() {
+	rsync -avzP --delete ftp.rfc-editor.org::rfcs-text-only "$D"
+	STATUS=$?
+	if [ "$STATUS" != 0 ]; then
+		exit "$STATUS"
+	fi
+}
+
+check_local_db() {
+	if [ ! -e "$D" ]; then
+		if prompt "$PROMPT_DB"; then
+			update
+		else
+			echo 'No local RFC database to operate on.' >&2
+			exit 1
+		fi
+	fi
+}
+
+
+for flag in "$@"; do
+	case "$flag" in
+		--)
+			break
+			;;
+		--help)
+			usage
+			help
+			exit
+			;;
+		*)
+			;;
+	esac
+done
+
+while getopts 'wuh' flag; do
+	case "$flag" in
+		w)
+			WHERE=true
+			;;
+		u)
+			UPDATE=true
+			;;
+		h)
+			usage
+			help
+			exit
+			;;
+		*)
+			usage >&2
+			exit 2
+			;;
+	esac
+done
+shift $((OPTIND - 1))
+
+RFC_NUMBER="${1:-}"
+F="$D/rfc${RFC_NUMBER}.txt"
+
+check_local_db
+
+if [ "${UPDATE:-}" = true ]; then
+	update
+	exit
+fi
+
+eval "$(assert-arg "$RFC_NUMBER" 'RFC_NUMBER')"
+
+if [ ! -e "$F" ]; then
+	printf 'Given RFC_NUMBER "%s" does not exist at:\n%s\n' \
+		"$RFC_NUMBER" "$F" >&2
+	exit 2
+fi
+
+if [ "${WHERE:-}" = true ]; then
+	printf '%s\n' "$F"
+	exit
+else
+	view < "$F"
+	exit
+fi