basic common app packages

dotenv/write.go

@@ -0,0 +1,62 @@
+package dotenv
+
+import (
+	"fmt"
+	"os"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+//
+// ported from https://github.com/joho/godotenv/blob/main/godotenv.go
+//
+
+const doubleQuoteSpecialChars = "\\\n\r\"!$`"
+
+// Write serializes the given environment and writes it to a file.
+func Write(envMap map[string]string, filename string) error {
+	content, err := marshal(envMap)
+	if err != nil {
+		return err
+	}
+	file, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	_, err = file.WriteString(content + "\n")
+	if err != nil {
+		return err
+	}
+	return file.Sync()
+}
+
+// marshal outputs the given environment as a dotenv-formatted environment file.
+// Each line is in the format: KEY="VALUE" where VALUE is backslash-escaped.
+func marshal(envMap map[string]string) (string, error) {
+	lines := make([]string, 0, len(envMap))
+	for k, v := range envMap {
+		if d, err := strconv.Atoi(v); err == nil {
+			lines = append(lines, fmt.Sprintf(`%s=%d`, k, d))
+		} else {
+			lines = append(lines, fmt.Sprintf(`%s="%s"`, k, doubleQuoteEscape(v)))
+		}
+	}
+	sort.Strings(lines)
+	return strings.Join(lines, "\n"), nil
+}
+
+func doubleQuoteEscape(line string) string {
+	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
+}