hadoop fs

The hadoop fs command runs a generic file system user client that interacts with the MapR file system.

Warning: On the Windows client, make sure that the PATH contains the following directories:
  • C:\Windows\system32
  • C:\Windows

If they are not present, the hadoop fs command might fail silently.

Syntax

hadoop [ Generic Options ] fs 
        [-cat <src>]
        [-chgrp [-R] GROUP PATH...]
        [-chmod [-R] <MODE[,MODE]... | OCTALMODE> PATH...]
        [-chown [-R] [OWNER][:[GROUP]] PATH...]
        [-copyFromLocal <localsrc> ... <dst>]
        [-copyToLocal [-ignoreCrc] [-crc] <src> <localdst>]
        [-count[-q] <path>]
        [-cp <src> <dst>]
        [-df <path>]
        [-du <path>]
        [-dus <path>]
        [-expunge]
        [-get [-ignoreCrc] [-crc] <src> <localdst>]
        [-getfattr [-R] {-n name | -d} [-e <encoding>] <path>]
        [-getmerge <src> <localdst> [addnl]]
        [-help [cmd]]
        [-ls <path>]
        [-lsr <path>]
        [-mkdir <path>]
        [-moveFromLocal <localsrc> ... <dst>]
        [-moveToLocal <src> <localdst>]
        [-mv <src> <dst>]
        [-put <localsrc> ... <dst>]
        [-rm [-skipTrash] <src>]
        [-rmr [-skipTrash] <src>]
        [-setfattr -n name [-v value] | -x name <path>]
        [-stat [format] <path>]
        [-tail [-f] <path>]
        [-test -[ezd] <path>]
        [-text <path>]
        [-touchz <path>]

Parameters

Command Options

The following command parameters are supported for hadoop fs:

Parameter

Description

-cat <src>

Fetch all files that match the file pattern defined by the <src> parameter and display their contents on stdout.

-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 rwxXt. That is, +t,a+r,g-w,+rwx,o=r OCTALMODE Mode specifed in 3 or 4 digits. If 4 digits, the first may be 1 or 0 to turn the sticky bit on or off, respectively. Unlike shell command, it is not possible to specify only part of the mode 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 consists 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 ...

-copyFromLocal <localsrc> ... <dst>

Identical to the -put command.

-copyToLocal [-ignoreCrc] [-crc] <src> <localdst>

Identical to the -get command.

-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

-cp <src> <dst>

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

-df [<path>]

Shows the capacity, free and used space of the filesystem. If the filesystem has multiple partitions, and no path to a particular partition is specified, then the status of the root partitions will be shown.

-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).

-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).

-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. The local option 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.

-get [-ignoreCrc] [-crc] <src> <localdst>

Copy files that match the file pattern <src> to the local name. <src> is kept. When copying multiple files, the destination must be a directory.

getfattr [-R] -n <name> | -d [-e <encoding>] <path> Retrieve all the extended attribute values (if any) for a file or directory. Here:
-R
Recursively list the attributes for all files and directories.
-n <name>
The name of the extended attribute to retrieve.
-d
Retrieve all extended attributes associated with the pathname. Extended attributes to which the calling process does not have access may be omitted from the list.
-e <encoding>
Encode values after retrieving them. Valid encodings are text (enclosed in double quotes), hex (prefixed with 0x), and base64 (prefixed with 0s).
<path>
The file or 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.

-help [cmd]

Displays help for given command or all commands if none is 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.

-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.

-mkdir <path>

Create a directory in specified location.

-moveFromLocal <localsrc> ... <dst>

Same as -put, except that the source is deleted after it's copied.

-moveToLocal <src> <localdst>

Not implemented yet

-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.

-put <localsrc> ... <dst>

Copy files from the local file system into fs. To copy files, user must have write permission on the directory or the addchild, deletechild, and writefile access set using ACEs.

-rm [-skipTrash] <src>

Delete all files that match the specified file pattern. Equivalent to the Unix command rm <src>. The -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> The -skipTrash option bypasses trash, if enabled, and immediately deletes <src>

-setfattr -n <name> [-v <value>] | -x <name> <path> Set or remove an extended attribute name and value. Here:
-n <name>
The name of the extended attribute to set.
-v <value>
The value of the extended attribute to set.
-x <name>
The name of the extended attribute to remove.
<path>
The file or directory.

-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)

-tail [-f] <file>

Show the last 1KB of the file. The -f option shows appended 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.

Generic Options

The following generic options are supported for the hadoop fs command: -conf <configuration file>, -D <property=value>, -fs <local|file system URI>, -jt <local|jobtracker:port>, -files <file1,file2,file3,...>, -libjars <libjar1,libjar2,libjar3,...>, and -archives <archive1,archive2,archive3,...>. For more information on generic options, see Generic Options.

Examples

Set an extended attribute on a file, file1.txt:
hadoop fs -setfattr -n user.key1 -v val1 /xattrs/m7user1/file1.txt
Remove an extended attribute specified by name:
hadoop fs -setfattr -x user.key1 /xattrs/m7user1/dir1
Retrieve an extended attribute for a file encoded in text:
[root@qa-node110 ~]# hadoop fs -getfattr -n user.key1 -e text /xattr/file1
# file: /xattr/file1
user.key1="value1"
Retrieve an extended attribute for a file encoded in hex:
[root@qa-node110 ~]# hadoop fs -getfattr -n user.key1 -e hex /xattr/file1
# file: /xattr/file1
user.key1=0x76616c756531
Retrieve an extended attribute for a file encoded in base64:
[root@qa-node110 ~]# hadoop fs -getfattr -n user.key1 -e base64 /xattr/file1
# file: /xattr/file1
user.key1=0sdmFsdWUx
Retrieve an extended attribute specified by name:
[root@qa-node110 ~]# hadoop fs -getfattr -n user.key1 /xattr/file2
# file: /xattr/file2
user.key1="value1"
Retrieve all the extended attributes associated with the given file:
[root@qa-node110 ~]# hadoop fs -getfattr -d /xattr/file2
# file: /xattr/file2
user.key2="value2"
user.key1="value1"
Retrieve extended attributes recursively:
[root@qa-node110 ~]# hadoop fs -getfattr -R -d /xattr/
# file: /xattr
# file: /xattr/file1
user.key2="value2"
# file: /xattr/file2
user.key2="value2"
user.key1="value1"
Retrieve a specific extended attribute recursively on a directory:
[root@qa-node110 ~]# hadoop fs -getfattr -R -n user.key1 /xattr/
# file: /xattr
user.key1="value1"
# file: /xattr/file1
getfattr: No such attribute
# file: /xattr/file2
user.key1="value1"