How to create a csv file of saved search using script

Use the task module

   //Create a task for saved search           

 let searchTask = task.create({                   

taskType: task.TaskType.SEARCH               

});               

searchTask.savedSearchId = saved search internal id;
searchTask.filePath = filePath//where the csv file should stored;
//Submit the process               

let searchTaskId = searchTask.submit();

we can add the related map/reduce or scheduled script to further process. For that add the code mentioned below.

// Create a map/reduce script task               

let mapReduceScript = task.create({                   

taskType: task.TaskType.MAP_REDUCE               

});               

mapReduceScript.scriptId = scriptId;               

mapReduceScript.deploymentId = deploymentId;
                //Create a rask for the dependent script               

let searchTask = task.create({                   

taskType: task.TaskType.SEARCH               

});               

searchTask.savedSearchId = file;
 searchTask.filePath = filePath;
 searchTask.addInboundDependency(mapReduceScript);
 //Submit the process             

searchTask.submit();