Initial commit.

.editorconfig

@@ -0,0 +1,7 @@
+[*.go]
+indent_style=tab
+indent_size=4
+trim_trailing_whitespace=true
+insert_final_newline=true
+max_line_length=120
+charset=utf-8

.gitignore

@@ -0,0 +1 @@
+goenvalue

main.go

@@ -0,0 +1,91 @@
+package main
+
+import (
+	"flag"
+	"os"
+	"strings"
+	"text/template"
+)
+
+const envDelimiter string = "="
+const paramsListDelimiter string = ","
+const paramsListSuffix string = "LIST"
+
+type envContainer struct {
+	Value string
+	List  []string
+}
+
+func getArgs() (string, string, string) {
+	inFileName := flag.String("i", "", "Input file name")
+	outFileName := flag.String("o", "", "Output file name")
+	prefix := flag.String("p", "", "Prefix for environment variables")
+	flag.Parse()
+
+	if len(*inFileName) == 0 {
+		os.Stderr.WriteString("Input file name not present\n")
+		os.Exit(1)
+	}
+
+	if len(*outFileName) == 0 {
+		os.Stderr.WriteString("Output file name not present\n")
+		os.Exit(1)
+	}
+
+	if len(*prefix) == 0 {
+		os.Stderr.WriteString("Prefix not present\n")
+		os.Exit(1)
+	}
+
+	return *inFileName, *outFileName, *prefix
+}
+
+func getParams(prefix string, suffix string, delimiter string) map[string]envContainer {
+	prefixShift := len(prefix) + 1
+	suffixLen := len(suffix)
+	tplParams := make(map[string]envContainer)
+
+	for _, e := range os.Environ() {
+		pair := strings.Split(e, envDelimiter)
+		if strings.HasPrefix(pair[0], prefix) {
+			var paramName string
+			var paramValue string
+			var paramList []string
+			if strings.HasSuffix(pair[0], suffix) {
+				suffixShift := len(pair[0]) - suffixLen - 1
+				paramName = pair[0][prefixShift:suffixShift]
+				paramValue = pair[1]
+				paramList = strings.Split(pair[1], delimiter)
+			} else {
+				paramName = pair[0][prefixShift:]
+				paramValue = pair[1]
+				paramList = []string{pair[1]}
+			}
+			tplParams[paramName] = envContainer{paramValue, paramList}
+		}
+	}
+
+	return tplParams
+}
+
+func main() {
+	var inFileName string
+	var outFileName string
+	var prefix string
+
+	inFileName, outFileName, prefix = getArgs()
+
+	tmpl, err := template.ParseFiles(inFileName)
+	if err != nil {
+		panic(err)
+	}
+
+	out, err := os.Create(outFileName)
+	if err != nil {
+		panic(err)
+	}
+
+	tplParams := getParams(prefix, paramsListSuffix, paramsListDelimiter)
+
+	tmpl.Execute(out, tplParams)
+}