Hadoop Command reference - Apache 3.0.0 Commands | W3schools

The Hadoop commands follow a similar structure and hence are easy to implement. The command structure is:

shellcommand [SHELL_OPTIONS] [COMMAND] [GENERIC_OPTIONS] [COMMAND_OPTIONS]

Also Read: Hadoop Environment Setup

Shellcommand

The shellcommand defines the command of a project that is being executed. HDFS framework uses hdfs as shellcommand and the YARN framework uses yarn as the shellcommand and the Hadoop common uses Hadoop as shellcommand.

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Shell Options

This contains the options that the shell script has to process before executing Java. Most of the shell commands have a common option set. For executing some commands these options can be ignored. Few Shell options are:

1. –buildpaths: used to enable Java version.

2. –config confdir: used to change the default config directory.

3. –debug: provides debugging information

4. –help: provides support documents for Shell script.

5. –loglevel loglevel: used to override the log levels.

6.–hostname: define the hostnames to run a multi-host command.

Generic Options

These are the common set of configuration options supported by many commands.

1. –archives: user can give a comma separated archive list to unarchive on the server.

2. -conf <configuration file>: used to specify the configuration file.

3. -files <comma separated list of files>: to specify comma separated files to be copied to map reduce cluster.

4. -jt <local> or <resourcemanager:port>: to define a resource manager.

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Basic user commands

1. ls <path>: Displays the contents of the folder or directory with details like name, permissions, size etc.

2. du <path>: Displays the disk usage in bytes for the specified directory.

4. mv <src><dest>: Moves a file indicated by src to dest.

5. cp <src> <dest>: Copies a file indicated by src to dest.

6. rm <path>: Removes a file from a location.

7. mkdir <path>: creates a directory in the defined path.

8. test -[ezd] <path>: If path exists the command returns 1, else 0.

19. touchz <path>: creates a file with the current time as a timestamp in the path location.