Shell脚本中的if语句-声明性管道

Question

我在外壳脚本声明性管道中使用以下if语句：

def currTaskDef = sh (
returnStdout: true,
script:  """
         #!/bin/bash
         RESULT=`(aws ecs describe-task-definition --task-definition ${env.TASK_FAMILY} | egrep 'revision' | tr ',' ' ' | awk '{print \$2}') 2> /dev/null`
         if ( ! "\$RESULT" ) then
            echo 1
         else                                                                    
              aws ecs describe-task-definition  --task-definition ${env.TASK_FAMILY} \
                                              | egrep 'revision'                     \
                                              | tr ',' ' '                           \
                                              | awk '{print \$2}'
         fi
         """
).trim()

我正在关注以下权限被拒绝

：

/home/jenkins/workspace/dev-test-local@tmp/durable-28ccc40c/script.sh: 4: /home/jenkins/workspace/dev-test-local@tmp/durable-28ccc40c/script.sh: : Permission denied
...
Finished: SUCCESS

如果我使用bash if语句if不起作用：

if [[ ! "\$RESULT" ]]; then
  echo 1 
else                                                                   
    aws ecs describe-task-definition  --task-definition ${env.TASK_FAMILY} \
                                    | egrep 'revision'                     \
                                    | tr ',' ' '                           \
                                    | awk '{print \$2}'                    \
fi

输出：

+ [[ !  ]]
/home/jenkins/workspace/dev-test-local@tmp/durable-d7af8721/script.sh: 4: /home/jenkins/workspace/dev-test-local@tmp/durable-d7af8721/script.sh: [[: not found

如何摆脱被拒绝的权限以及为什么bash if语句不起作用？