fix!: Use %b in generated printf statements (vs %s)

%b is a posix printf standard, so this should just be an improvement, correcting behavior for shells like DASH.

Adds new function, escape_string, which creates a string compatible with %b

bash-tpl

@@ -352,6 +352,7 @@ function escape_string {
 	# Escape '\' first since we'll be adding more later
 	local e="${!1//$'\\'/\\}"
 	# Some man pages mention \0NNN but in practice it seems \NNN is also works.
+	e="${e//\\/\\\\}"
 	e="${e//\'/\\0047}"
 	e="${e//$'\a'/\\a}"
 	e="${e//$'\b'/\\b}"
@@ -575,7 +576,7 @@ function process_tags() {
 		# Assume next character is TEXT - extract and process remainder
 		#
 		elif [[ "${line}" =~ (.)(.*) ]]; then
-			# echo "# DEFAULT: Assuming first char is TEXT: $(declare -p line)"
+			# echo "# DEFAULT: Assuming first char is TEXT: $(declare -p line)" >&2
 			quoted="${BASH_REMATCH[1]}"
 			escape_string quoted
 			#printf -v quoted "%q" "${BASH_REMATCH[1]}"

test/tpl/text_with_dollar.sh

@@ -0,0 +1,5 @@
+printf "%b\n" '$Hello'
+printf "%b\n" '<$Hello'
+printf "%b%b\n" '<' '%$Hello'
+printf "%b%b\n" '<' '<$Hello'
+printf "%b\n" '%$Hello'

test/tpl/text_with_dollar.tpl

@@ -0,0 +1,5 @@
+$Hello
+<$Hello
+<%$Hello
+<<$Hello
+%$Hello

test/tpl/text_with_dollar.txt

@@ -0,0 +1,5 @@
+$Hello
+<$Hello
+<%$Hello
+<<$Hello
+%$Hello

test/tpl/text_with_escapes.sh

@@ -1,5 +1,5 @@
-printf "%b\n" '\tHello'
-printf "%b\n" '<\tHello'
-printf "%b%b\n" '<' '%\tHello'
-printf "%b%b\n" '<' '<\tHello'
-printf "%b\n" '%\tHello'
+printf "%b\n" '\\tHello'
+printf "%b\n" '<\\tHello'
+printf "%b%b\n" '<' '%\\tHello'
+printf "%b%b\n" '<' '<\\tHello'
+printf "%b\n" '%\\tHello'

test/tpl/text_with_escapes.txt

@@ -1,5 +1,5 @@
-	Hello
-<	Hello
-<%	Hello
-<<	Hello
-%	Hello
+\tHello
+<\tHello
+<%\tHello
+<<\tHello
+%\tHello

test/tpl/text_with_quotes.sh

@@ -0,0 +1,12 @@
+printf "%b\n" '\0047Hello'
+printf "%b\n" '<\0047Hello'
+printf "%b%b\n" '<' '%\0047Hello'
+printf "%b%b\n" '<' '<\0047Hello'
+printf "%b\n" '%\0047Hello'
+printf "%b\n" '"Hello'
+printf "%b\n" '<"Hello'
+printf "%b%b\n" '<' '%"Hello'
+printf "%b%b\n" '<' '<"Hello'
+printf "%b\n" '%"Hello'
+printf "%b\n" 'Hello \0047World\0047'
+printf "%b\n" 'Hello "World"'

test/tpl/text_with_quotes.tpl

@@ -0,0 +1,12 @@
+'Hello
+<'Hello
+<%'Hello
+<<'Hello
+%'Hello
+"Hello
+<"Hello
+<%"Hello
+<<"Hello
+%"Hello
+Hello 'World'
+Hello "World"

test/tpl/text_with_quotes.txt

@@ -0,0 +1,12 @@
+'Hello
+<'Hello
+<%'Hello
+<<'Hello
+%'Hello
+"Hello
+<"Hello
+<%"Hello
+<<"Hello
+%"Hello
+Hello 'World'
+Hello "World"

test/tpl/text_with_tabs.sh

@@ -0,0 +1,5 @@
+printf "%b\n" '\tHello'
+printf "%b\n" '<\tHello'
+printf "%b%b\n" '<' '%\tHello'
+printf "%b%b\n" '<' '<\tHello'
+echo Hello

test/tpl/text_with_tabs.tpl

@@ -0,0 +1,5 @@
+	Hello
+<	Hello
+<%	Hello
+<<	Hello
+%	echo Hello

test/tpl/text_with_tabs.txt

@@ -0,0 +1,5 @@
+	Hello
+<	Hello
+<%	Hello
+<<	Hello
+Hello