Hadoop in Action

Appendix A. HDFS file commands

This appendix lists the HDFS commands for managing files. They’re in the form of

hadoop fs -cmd <args>

where cmd is the specific file command and <args> is a variable number of arguments.

You can see the command usage in the following convention. Parameters inside brackets ([]) are optional and ellipsis (. . .) means the optional parameter can be repeated. FILE is for filenames whereas PATH can be either filenames or directory names. SRC and DST are path names but they function specifically as source and destination, respectively. LOCALSRC and LOCALDST are further required to be on the local filesystem.

Command	Usage and description
cat	hadoop fs –cat FILE [FILE ...] Displays the files’ content. For reading ...