feat(single): Implement autoescaping

1 files changed, 22 insertions, 1 deletions

diff --git a/single.awk b/single.awk
index e19117d..a27d61c 100644
--- a/single.awk
+++ b/single.awk
@@ -1,6 +1,6 @@
 # Status:
 # [.] Inline HTML
-# [ ] Autoescape
+# [x] Autoescape
 # [.] Block elements
 #     [x] Paragraph
 #     [x] Line break
@@ -155,6 +155,14 @@ blockquote_level > 0 && empty0 {
 		P1 = P1 "<pre><code>"
 		inside_codeblock = 1
 	}
+
+	## Autoescape & and <
+	for (i = 1; match(substr($0, i), /&/); i += RSTART) {
+		RSTART += i - 1
+		sub_match("&amp;")
+	}
+	gsub(/</, "\\&lt;")
+
 	_next()
 }
 inside_codeblock && ! /^[ \t]*$/ {
@@ -192,6 +200,19 @@ inside_codeblock && ! /^[ \t]*$/ {
 	}
 }
 
+# Autoescape &
+/&/ {
+	for (i = 1; match(substr($0, i), /&/); i += RSTART) {
+		RSTART += i - 1
+		if (substr($0, RSTART) ~ /&[A-Za-z0-9#]+;/) { continue }
+		sub_match("&amp;")
+	}
+}
+# Autoescape <
+/ < / {
+	gsub(/ < /, "\\&lt;")
+}
+
 # Line break
 /  $/ {
 	sub(/[ \t]*  $/, "</br>")