HDFS - Command 1

HDFS is used to store the files of different size and will be very useful for the data set which are very big in size.

We will have a look into the some of the basic commands that can be used in HDFS.

Directory Creation (mkdir):- The directory in HDFS can be created with the help of 'mkdir' command.

Syntax :- hdfs fs -mkdir dirname

we can also create the directory by giving the path .

Syntax :- hdfs fs -mkdir pathname/dirname

Listing directory and files( ls ) :- The files and directory can be viewed via 'ls' command in the HDFS.

Syntax :- hdfs fs -ls

We can list the files and directory by giving the specified path.

Syntax :- hdfs fs -ls pathname

Displaying the file (cat ) :- 'cat' command is used to display the contents of the file.

We will create a file in our local filesystem.

Syntax :- cat > file,txt

Now we will display the contents of the file after sending the file in HDFS using the command cat.

Syntax :- hdfs fs -cat file.txt

Sending the file via put command :- We can send the file from local filesystem to the hdfs via 'put' command.

Note :- put command can be used to transfer file from one location to another.

Syntax :- hdfs fs -put path1 path2

If we want to send the same file to the hdfs , we will get an error “File exists” .

To avoid this error , we can send the file using the option -f .

Syntax :- hdfs fs -put -f path1 path2

Copying File in HDFS :- We can copy the file from one location to another via 'cp' command .

Syntax :- hdfs fs -cp path1 path2

Moving file in HDFS :- We can transfer the file from one location to another via 'mv' command .

Syntax :- hdfs fs -mv path1 path2