Hadoop FS Shell stat

Introduction

In this lab, we will explore the Hadoop HDFS skill point "FS Shell stat" within the context of a scenario set in the legendary tale of a sunken shipwreck treasure cove. Imagine a scenario where the undiscovered treasures of a sunken ship are said to be buried deep within the ocean floor of the Treasure Cove. You play the role of a renowned narrator of this treasure hunting legend whose task is to guide explorers to uncover the hidden riches.

Exploring FS Shell stat

In this step, we will delve into the hadoop fs -stat command to gather detailed information about a specific file in Hadoop HDFS.

1. switch to the hadoop user:

   su - hadoop
   

2. create a file named treasure.txt in the current directory:

   vim treasure.txt
   

3. the content in treasure.txt is:

   hello world
   

4. put the treasure.txt file into the Hadoop file system:

   hadoop fs -put treasure.txt /user/hadoop/
   

5. Use the following command to display the attributes of a file named treasure.txt in the Hadoop file system:

   hadoop fs -stat %g-%F-%b-%y-%Y-%o /user/hadoop/treasure.txt
   

   the parameters in the command are:

   %g: Group name of owner
   %F: File type
   %b: Length in bytes
   %y: Modification timestamp
   %Y: Access timestamp
   %o: Block size
   

6. The output will provide information such as file permissions, file type, modification time, access time, and block size. like this:

   supergroup-regular file-12-2024-03-08 12:42:00-1709901720659-134217728
   

Analyzing File Permissions

In this step, we will focus on understanding and analyzing the file permissions using the hadoop fs -stat command.

1. Execute the following command to view the file permissions of the treasure.txt file:

   hadoop fs -stat %F-%A /user/hadoop/treasure.txt
   

   the parameters in the command are:

   %F: File type
   %A: File permissions
   

2. The output will display the file type and permissions associated with the file. like this:

   regular file-rw-r--r--
   

Summary

In this lab, we explored the hadoop fs -stat command within the Hadoop HDFS environment to retrieve detailed file information. By following the step-by-step guide, users can gain a better understanding of how to utilize this command for file attribute analysis and permission verification in Hadoop. This lab aims to provide hands-on experience for beginners to familiarize themselves with FS Shell stat operations in Hadoop.