hadoop系统命令

hadoop fs is the command to execute fs commands. The full syntax is: 


hadoop fs [-fs <local | file system URI>] [-conf <configuration file>]
        [-D <property=value>] [-ls <path>] [-lsr <path>] [-du <path>]
        [-dus <path>] [-mv <src> <dst>] [-cp <src> <dst>] [-rm [-skipTrash] <src>]
        [-rmr [-skipTrash] <src>] [-put <localsrc> ... <dst>] [-copyFromLocal <localsrc> ... <dst>]
        [-moveFromLocal <localsrc> ... <dst>] [-get [-ignoreCrc] [-crc] <src> <localdst>
        [-getmerge <src> <localdst> [addnl]] [-cat <src>]
        [-copyToLocal [-ignoreCrc] [-crc] <src> <localdst>] [-moveToLocal <src> <localdst>]
        [-mkdir <path>] [-report] [-setrep [-R] [-w] <rep> <path/file>]
        [-touchz <path>] [-test -[ezd] <path>] [-stat [format] <path>]
        [-tail [-f] <path>] [-text <path>]
        [-chmod [-R] <MODE[,MODE]... | OCTALMODE> PATH...]
        [-chown [-R] [OWNER][:[GROUP]] PATH...]
        [-chgrp [-R] GROUP PATH...]
        [-count[-q] <path>]
        [-help [cmd]]


-fs [local | <file system URI>]:        Specify the file system to use.
                If not specified, the current configuration is used, 
                taken from the following, in increasing precedence: 
                        core-default.xml inside the hadoop jar file 
                        core-site.xml in $HADOOP_CONF_DIR 
                'local' means use the local file system as your DFS. 
                <file system URI> specifies a particular file system to 
                contact. This argument is optional but if used must appear
                appear first on the command line.  Exactly one additional
                argument must be specified. 


-ls <path>:     List the contents that match the specified file pattern. If
                path is not specified, the contents of /user/<currentUser>
                will be listed. Directory entries are of the form 
                        dirName (full path) <dir> 
                and file entries are of the form 
                        fileName(full path) <r n> size 
                where n is the number of replicas specified for the file 
                and size is the size of the file, in bytes.
                 列出与指定的模式相匹配的的文件。如果路径没有说明，将会列出当前用户目录下的文件。

-lsr <path>:    Recursively list the contents that match the specified
                file pattern.  Behaves very similarly to hadoop fs -ls,
                except that the data is shown for all the entries in the
                subtree.
                迭代的列出指定模式的文件列表。

-du <path>:     Show the amount of space, in bytes, used by the files that 
                match the specified file pattern.  Equivalent to the unix
                command "du -sb <path>/*" in case of a directory, 
                and to "du -b <path>" in case of a file.
                The output is in the form 
                        name(full path) size (in bytes)
以字节的方式显示文件空间大小。

-dus <path>:    Show the amount of space, in bytes, used by the files that 
                match the specified file pattern.  Equivalent to the unix
                command "du -sb"  The output is in the form 
                        name(full path) size (in bytes)


-mv <src> <dst>:   Move files that match the specified file pattern <src>
                to a destination <dst>.  When moving multiple files, the 
                destination must be a directory. 


-cp <src> <dst>:   Copy files that match the file pattern <src> to a 
                destination.  When copying multiple files, the destination
                must be a directory. 


-rm [-skipTrash] <src>:         Delete all files that match the specified file pattern.
                Equivalent to the Unix command "rm <src>"
                -skipTrash option bypasses trash, if enabled, and immediately
deletes <src>
-rmr [-skipTrash] <src>:        Remove all directories which match the specified file 
                pattern. Equivalent to the Unix command "rm -rf <src>"
                -skipTrash option bypasses trash, if enabled, and immediately
deletes <src>
-put <localsrc> ... <dst>:      Copy files from the local file system 
                into fs. 


-copyFromLocal <localsrc> ... <dst>: Identical to the -put command.


-moveFromLocal <localsrc> ... <dst>: Same as -put, except that the source is
                deleted after it's copied.


-get [-ignoreCrc] [-crc] <src> <localdst>:  Copy files that match the file pattern <src> 
                to the local name.  <src> is kept.  When copying mutiple, 
                files, the destination must be a directory. 


-getmerge <src> <localdst>:  Get all the files in the directories that 
                match the source file pattern and merge and sort them to only
                one file on local fs. <src> is kept.


-cat <src>:     Fetch all files that match the file pattern <src> 
                and display their content on stdout.


-copyToLocal [-ignoreCrc] [-crc] <src> <localdst>:  Identical to the -get command.


-moveToLocal <src> <localdst>:  Not implemented yet 


-mkdir <path>:  Create a directory in specified location. 


-setrep [-R] [-w] <rep> <path/file>:  Set the replication level of a file. 
                The -R flag requests a recursive change of replication level 
                for an entire tree.


-tail [-f] <file>:  Show the last 1KB of the file. 
                The -f option shows apended data as the file grows. 


-touchz <path>: Write a timestamp in yyyy-MM-dd HH:mm:ss format
                in a file at <path>. An error is returned if the file exists with non-zero length


-test -[ezd] <path>: If file { exists, has zero length, is a directory
                then return 0, else return 1.


-text <src>:    Takes a source file and outputs the file in text format.
                The allowed formats are zip and TextRecordInputStream.


-stat [format] <path>: Print statistics about the file/directory at <path>
                in the specified format. Format accepts filesize in blocks (%b), filename (%n),
                block size (%o), replication (%r), modification date (%y, %Y)


-chmod [-R] <MODE[,MODE]... | OCTALMODE> PATH...
                Changes permissions of a file.
                This works similar to shell's chmod with a few exceptions.


        -R      modifies the files recursively. This is the only option
                currently supported.


        MODE    Mode is same as mode used for chmod shell command.
                Only letters recognized are 'rwxX'. E.g. a+r,g-w,+rwx,o=r


        OCTALMODE Mode specifed in 3 digits. Unlike shell command,
                this requires all three digits.
                E.g. 754 is same as u=rwx,g=rx,o=r


                If none of 'augo' is specified, 'a' is assumed and unlike
                shell command, no umask is applied.


-chown [-R] [OWNER][:[GROUP]] PATH...
                Changes owner and group of a file.
                This is similar to shell's chown with a few exceptions.


        -R      modifies the files recursively. This is the only option
                currently supported.


                If only owner or group is specified then only owner or
                group is modified.


                The owner and group names may only cosists of digits, alphabet,
                and any of '-_.@/' i.e. [-_.@/a-zA-Z0-9]. The names are case
                sensitive.


                WARNING: Avoid using '.' to separate user name and group though
                Linux allows it. If user names have dots in them and you are
                using local file system, you might see surprising results since
                shell command 'chown' is used for local files.


-chgrp [-R] GROUP PATH...
                This is equivalent to -chown ... :GROUP ...


-count[-q] <path>: Count the number of directories, files and bytes under the paths
                that match the specified file pattern.  The output columns are:
                DIR_COUNT FILE_COUNT CONTENT_SIZE FILE_NAME or
                QUOTA REMAINING_QUATA SPACE_QUOTA REMAINING_SPACE_QUOTA 
                      DIR_COUNT FILE_COUNT CONTENT_SIZE FILE_NAME
-help [cmd]:    Displays help for given command or all commands if none