working epics ioc and tested

pkg/ca/client.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"fmt"
 	"os"
-	"path/filepath"
+	"os/user"
 	"strings"
 	"sync"
 
@@ -42,11 +42,18 @@ type Config struct {
 //	EPICS_CA_ADDR_LIST        — space-separated list of server addresses
 //	EPICS_CA_AUTO_ADDR_LIST   — "NO" disables automatic broadcast addresses
 func ConfigFromEnv() Config {
-	name := filepath.Base(os.Args[0])
+	// CA security ACLs match on the client username, not the program name.
+	// Use the OS username (same as libca), falling back to $USER, then "user".
+	clientName := "user"
+	if u, err := user.Current(); err == nil && u.Username != "" {
+		clientName = u.Username
+	} else if v := os.Getenv("USER"); v != "" {
+		clientName = v
+	}
 	host, _ := os.Hostname()
 	cfg := Config{
 		AutoAddrList: true,
-		ClientName:   name,
+		ClientName:   clientName,
 		HostName:     host,
 	}
 	if v := os.Getenv("EPICS_CA_ADDR_LIST"); v != "" {
@@ -103,7 +110,13 @@ func NewClient(ctx context.Context, cfg Config) (*Client, error) {
 	}
 
 	if cfg.ClientName == "" {
-		cfg.ClientName = filepath.Base(os.Args[0])
+		if u, err := user.Current(); err == nil && u.Username != "" {
+			cfg.ClientName = u.Username
+		} else if v := os.Getenv("USER"); v != "" {
+			cfg.ClientName = v
+		} else {
+			cfg.ClientName = "user"
+		}
 	}
 	if cfg.HostName == "" {
 		cfg.HostName, _ = os.Hostname()