1 files changed, 117 insertions, 0 deletions
diff --git a/bin/rfc b/bin/rfc
new file mode 100755
index 0000000..a483595
--- /dev/null
+++ b/bin/rfc
@@ -0,0 +1,117 @@
+#!/bin/sh
+set -eu
+
+TARBALL_URL='https://www.rfc-editor.org/in-notes/tar/RFC-all.tar.gz'
+
+usage() {
+	cat <<-'EOF'
+		Usage:
+		  rfc [-w] RFC_NUMBER
+		  rfc -h
+	EOF
+}
+
+help() {
+	cat <<-'EOF'
+
+		Options:
+		  -w            Show the path to the RFC file instead of displaying
+		                its contents.
+		  -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 $XDG_DATA_HOME/doc/rfc/ directory doesn't exist, it tries to
+		create it by downloading the latest RFC tarball [0] and placing all .txt
+		files there.
+	EOF
+
+	printf '\n[0]: %s\n' "$TARBALL_URL"
+}
+
+for flag in "$@"; do
+	case "$flag" in
+		--)
+			break
+			;;
+		--help)
+			usage
+			help
+			exit
+			;;
+		*)
+			;;
+	esac
+done
+
+while getopts 'wh' flag; do
+	case "$flag" in
+		w)
+			WHERE=true
+			;;
+		h)
+			usage
+			help
+			exit
+			;;
+		*)
+			usage >&2
+			exit 2
+			;;
+	esac
+done
+shift $((OPTIND - 1))
+
+RFC_NUMBER="${1:-}"
+if [ -z "$RFC_NUMBER" ]; then
+	echo 'Missing argument RFC_NUMBER' >&2
+	usage >&2
+	exit 2
+fi
+
+D="${XDG_DATA_HOME:-$HOME/.local/share}/doc/rfc"
+if [ ! -e "$D" ]; then
+	printf 'RFC directory does not exist:\n\t%s/\n\n' "$D"
+	printf 'Do you want to download the files to create it? [Y/n] '
+	read -r yesno
+	if [ "$yesno" != 'n' ] && [ "$yesno" != 'N' ]; then
+		CACHE_DIR="${XDG_CACHE_HOME:-$HOME/.cache}/rfc-cli"
+		mkdir -p "$CACHE_DIR"
+		wget -cO "$CACHE_DIR"/RFC-all.tar.gz "$TARBALL_URL"
+		rm -rf "$CACHE_DIR/tmp"
+		mkdir -p "$CACHE_DIR/tmp"
+		tar \
+			-C "$CACHE_DIR/tmp"              \
+			-xvf "$CACHE_DIR"/RFC-all.tar.gz \
+			--wildcards                      \
+			'rfc*.txt'
+		mkdir -p "$(dirname "$D")"
+		mv "$CACHE_DIR/tmp" "$D"
+	fi
+fi
+
+F="$D/rfc${RFC_NUMBER}.txt"
+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
+fi
+
+view() {
+	if [ -t 1 ]; then
+		${PAGER:-cat}
+	else
+		cat
+	fi
+}
+
+view < "$F"