Use built-in function to read env vars from current shell

Author: SimonBaeumer

command.go

@@ -7,7 +7,6 @@ import (
 	"os"
 	"os/exec"
 	"regexp"
-	"strings"
 	"syscall"
 	"time"
 )
@@ -93,19 +92,10 @@ func WithoutTimeout(c *Command) {
 // AddEnv adds an environment variable to the command
 // If a variable gets passed like ${VAR_NAME} the env variable will be read out by the current shell
 func (c *Command) AddEnv(key string, value string) {
-	vars := parseEnvVariableFromShell(value)
-	for _, v := range vars {
-		value = strings.Replace(value, v, os.Getenv(removeEnvVarSyntax(v)), -1)
-	}
-
+	value = os.ExpandEnv(value)
 	c.Env = append(c.Env, fmt.Sprintf("%s=%s", key, value))
 }
 
-// Removes the ${...} characters at the beginng and end of the given string
-func removeEnvVarSyntax(v string) string {
-	return v[2:(len(v) - 1)]
-}
-
 //Read all environment variables from the given value
 //with the syntax ${VAR_NAME}
 func parseEnvVariableFromShell(val string) []string {

command_test.go

@@ -81,8 +81,8 @@ func TestCommand_AddEnvWithShellVariable(t *testing.T) {
 }
 
 func TestCommand_AddMultipleEnvWithShellVariable(t *testing.T) {
-	const TestEnvKeyPlanet = "COMMANDER_TEST_PLANET"
-	const TestEnvKeyName = "COMMANDER_TEST_NAME"
+	const TestEnvKeyPlanet = "CMD_TEST_PLANET"
+	const TestEnvKeyName = "CMD_TEST_NAME"
 	os.Setenv(TestEnvKeyPlanet, "world")
 	os.Setenv(TestEnvKeyName, "Simon")
 	defer func() {