update some for exec command

Author: inhere

src/Exec.php

@@ -51,15 +51,20 @@ public static function exec(string $command, string $workDir = '', bool $outAsSt
      *
      * @return array
      */
-    public static function system(string $command, string $workDir = ''): array
+    public static function system(string $command, string $workDir = '', bool $allReturn = false): array
     {
         if ($workDir) {
             chdir($workDir);
         }
 
-        ob_start();
-        system($command, $status);
-        $output = ob_get_clean();
+        if ($allReturn) {
+            ob_start();
+            system($command, $status);
+            $output = ob_get_clean();
+        } else {
+            // only last line message
+            $output = system($command, $status);
+        }
 
         return [$status, $output];
     }

src/Proc/ProcWrapper.php

@@ -408,6 +408,18 @@ public function setCommand(string $command): self
         return $this;
     }
 
+    /**
+     * @param index $index
+     * @param array $spec
+     *
+     * @return ProcWrapper
+     */
+    public function setDescriptor(int $index, array $spec): self
+    {
+        $this->descriptors[$index] = $spec;
+        return $this;
+    }
+
     /**
      * @param array $descriptors
      *