escape some other bash-y special chars ($!)

godotenv.go

@@ -24,6 +24,8 @@ import (
 	"strings"
 )
 
+const doubleQuoteSpecialChars = "\\\n\r\"!$`"
+
 // Load will read your env file(s) and load them into ENV for this process.
 //
 // Call this function as close as possible to the start of your program (ideally in main)
@@ -297,9 +299,15 @@ func isIgnoredLine(line string) bool {
 }
 
 func doubleQuoteEscape(line string) string {
-	line = strings.Replace(line, `\`, `\\`, -1)
-	line = strings.Replace(line, "\n", `\n`, -1)
-	line = strings.Replace(line, "\r", `\r`, -1)
-	line = strings.Replace(line, `"`, `\"`, -1)
+	for _, c := range doubleQuoteSpecialChars {
+		toReplace := "\\" + string(c)
+		if c == '\n' {
+			toReplace = `\n`
+		}
+		if c == '\r' {
+			toReplace = `\r`
+		}
+		line = strings.Replace(line, string(c), toReplace, -1)
+	}
 	return line
 }

godotenv_test.go

@@ -346,8 +346,8 @@ func TestWrite(t *testing.T) {
 	writeAndCompare(`key=va"lu"e`, `key="va\"lu\"e"`)
 	//but single quotes are left alone
 	writeAndCompare(`key=va'lu'e`, `key="va'lu'e"`)
-	// newlines and backslashes are escaped
-	writeAndCompare(`foo="ba\n\r\\r!"`, `foo="ba\n\r\\r!"`)
+	// newlines, backslashes, and some other special chars are escaped
+	writeAndCompare(`foo="$ba\n\r\\r!"`, `foo="\$ba\n\r\\r\!"`)
 }
 
 func TestRoundtrip(t *testing.T) {