bin/html: Add new working utility

1 files changed, 96 insertions, 0 deletions

diff --git a/bin/html b/bin/html
new file mode 100755
index 0000000..f3f23de
--- /dev/null
+++ b/bin/html
@@ -0,0 +1,96 @@
+#!/bin/sh
+set -eu
+
+
+usage() {
+	cat <<-'EOF'
+		Usage:
+		  html [-e|d]
+		  html -h
+	EOF
+}
+
+help() {
+	cat <<-'EOF'
+
+		Options:
+		  -e            escape the string (the default action)
+		  -d            unescape (de-escape?) the string
+		  -h, --help    show this message
+
+
+		Get a string from STDIN and convert it to/from HTML escaping.
+
+
+		Examples:
+
+		  oij
+
+		    $ printf 'a > 5 && !b' | html
+		    a &gt; 5 &amp;&amp; !b
+
+
+		  Unescape the content from a file:
+
+		    $ html -d < file.html
+	EOF
+}
+
+
+for flag in "$@"; do
+	case "$flag" in
+		--)
+			break
+			;;
+		--help)
+			usage
+			help
+			exit
+			;;
+		*)
+			;;
+	esac
+done
+
+ENCODE=false
+DECODE=false
+while getopts 'edh' flag; do
+	case "$flag" in
+		e)
+			ENCODE=true
+			;;
+		d)
+			DECODE=true
+			;;
+		h)
+			usage
+			help
+			exit
+			;;
+		*)
+			usage >&2
+			exit 2
+			;;
+	esac
+done
+shift $((OPTIND - 1))
+
+if [ "$ENCODE" = true ] && [ "$DECODE" = true ]; then
+	printf 'Both -e and -d given.  Pick one.\n' >&2
+	usage >&2
+	exit 2
+elif [ "$DECODE" = true ]; then
+	sed \
+		-e 's|&amp;|\&|g'  \
+		-e 's|&lt;|<|g'   \
+		-e 's|&gt;|>|g'   \
+		-e 's|&quot;|"|g' \
+		-e "s|&#39;|'|g"
+else
+	sed \
+		-e 's|&|\&amp;|g'  \
+		-e 's|<|\&lt;|g'   \
+		-e 's|>|\&gt;|g'   \
+		-e 's|"|\&quot;|g' \
+		-e "s|'|\&#39;|g"
+fi