bin/hdfs dfs命令

appendToFile

Usage:?hdfs dfs -appendToFile <localsrc> ... <dst>

追加一個或者多個文件（linux文件）?<localsrc> ...到hdfs制定文件<dst>中.也可以從命令行讀取輸入.

hdfs dfs -appendToFile localfile /user/hadoop/hadoopfile

hdfs dfs -appendToFile localfile1 localfile2 /user/hadoop/hadoopfile

hdfs dfs -appendToFile localfile hdfs://nn.example.com/hadoop/hadoopfile

hdfs dfs -appendToFile - hdfs://nn.example.com/hadoop/hadoopfile?Reads the input from stdin.

當localsrc 是 - ?的時候，從命令行讀數。

?

Exit Code:

Returns 0 on success and 1 on error.

cat

Usage:?hdfs dfs -cat URI [URI ...]

查看內容.

Example:

hdfs dfs -cat hdfs://nn1.example.com/file1 hdfs://nn2.example.com/file2

hdfs dfs -cat file:///file3 /user/hadoop/file4

[hadoop@hello110 hadoop]$ hdfs dfs -cat /wc/output/part-r-00000 /wc/srcdata/word.log

boy ????1

girl ???1

hello ??4

mimi ???1

world ??1

hello world

hello girl

hello boy

hello mimi

Exit Code:

Returns 0 on success and -1 on error.

?

Chgrp【change group】

Usage:?hdfs dfs -chgrp [-R] GROUP URI [URI ...]

修改所屬組.

Options

The -R option will make the change recursively through the directory structure.

-R 修改全部的。不加-R，則只修改當前的。

chmod

Usage:?hdfs dfs -chmod [-R] <MODE[,MODE]... | OCTALMODE> URI [URI ...]

修改權限.

-rwxrwxrwx

- : 文件還是目錄。D：目錄

第一組rwx，文件創建者的權限

第二組rwx，用戶所在組的權限

第三組rwx，其他用戶的權限

Options

The -R option will make the change recursively through the directory structure.

-R 修改全部的。不加-R，則只修改當前的

chown

Usage:?hdfs dfs -chown [-R] [OWNER][:[GROUP]] URI [URI ]

修改所有者.

Options

The -R option will make the change recursively through the directory structure.

copyFromLocal

從本地拷貝

Usage:?hdfs dfs -copyFromLocal <localsrc> URI

Similar to put command, except that the source is restricted to a local file reference.

Options:

The -f option will overwrite the destination if it already exists.

copyToLocal

拷貝到本地

Usage:?hdfs dfs -copyToLocal [-ignorecrc] [-crc] URI <localdst>

Similar to get command, except that the destination is restricted to a local file reference.

count

Usage:?hdfs dfs -count [-q] [-h] <paths>

列出文件夾數量、文件數量、內容大小. The output columns with -count are: DIR_COUNT, FILE_COUNT, CONTENT_SIZE FILE_NAME

The output columns with -count -q are: QUOTA, REMAINING_QUATA, SPACE_QUOTA, REMAINING_SPACE_QUOTA, DIR_COUNT, FILE_COUNT, CONTENT_SIZE, FILE_NAME

The -h option shows sizes in human readable format.

Example:

hdfs dfs -count hdfs://nn1.example.com/file1 hdfs://nn2.example.com/file2

hdfs dfs -count -q hdfs://nn1.example.com/file1

hdfs dfs -count -q -h hdfs://nn1.example.com/file1

Exit Code:

Returns 0 on success and -1 on error.

cp

Usage:?hdfs dfs -cp [-f] [-p | -p[topax]] URI [URI ...] <dest>

復制文件(夾)，可以覆蓋，可以保留原有權限信息

Options:

The -f option will overwrite the destination if it already exists.

The -p option will preserve file attributes [topx] (timestamps, ownership, permission, ACL, XAttr). If -p is specified with no?arg, then preserves timestamps, ownership, permission. If -pa is specified, then preserves permission also because ACL is a super-set of permission. Determination of whether raw namespace extended attributes are preserved is independent of the -p flag.

-p參數，復制時文件權限不變

Example:

hdfs dfs -cp /user/hadoop/file1 /user/hadoop/file2

hdfs dfs -cp /user/hadoop/file1 /user/hadoop/file2 /user/hadoop/dir

Exit Code:

Returns 0 on success and -1 on error.

du

Usage:?hdfs dfs -du [-s] [-h] URI [URI ...]

顯示文件(夾)大小.

Options:

The -s option will result in an aggregate summary of file lengths being displayed, rather than the individual files.

The -h option will format file sizes in a "human-readable" fashion (e.g 64.0m instead of 67108864)

Example:

hdfs dfs -du /user/hadoop/dir1 /user/hadoop/file1 hdfs://nn.example.com/user/hadoop/dir1

Exit Code: Returns 0 on success and -1 on error.

dus

Usage:?hdfs dfs -dus <args>

Displays a summary of file lengths.

Note:?This command is deprecated. Instead use?hdfs dfs -du -s.

expunge

Usage:?hdfs dfs -expunge

清空回收站.

get

Usage:?hdfs dfs -get [-ignorecrc] [-crc] <src> <localdst>

Copy files to the local file system. Files that fail the CRC check may be copied with the -ignorecrc option. Files and CRCs may be copied using the -crc option.

Example:

hdfs dfs -get /user/hadoop/file localfile

hdfs dfs -get hdfs://nn.example.com/user/hadoop/file localfile

Exit Code:

Returns 0 on success and -1 on error.

getfacl

Usage:?hdfs dfs -getfacl [-R] <path>

顯示權限信息.

Options:

-R: List the ACLs of all files and directories recursively.

path: File or directory to list.

Examples:

hdfs dfs -getfacl /file

hdfs dfs -getfacl -R /dir

Exit Code:

Returns 0 on success and non-zero on error.

getfattr

Usage:?hdfs dfs -getfattr [-R]?-n name | -d?[-e en] <path>

Displays the extended attribute names and values (if any) for a file or directory.

Options:

-R: Recursively list the attributes for all files and directories.

-n name: Dump the named extended attribute value.

-d: Dump all extended attribute values associated with pathname.

-e?encoding: Encode values after retrieving them. Valid encodings are "text", "hex", and "base64". Values encoded as text strings are enclosed in double quotes ("), and values encoded as hexadecimal and base64 are prefixed with 0x and 0s, respectively.

path: The file or directory.

Examples:

hdfs dfs -getfattr -d /file

hdfs dfs -getfattr -R -n user.myAttr /dir

Exit Code:

Returns 0 on success and non-zero on error.

getmerge

Usage:?hdfs dfs -getmerge <src> <localdst> [addnl]

合并.

ls

Usage:?hdfs dfs -ls [-R] <args>

Options:

The -R option will return stat recursively through the directory structure.

For a file returns stat on the file with the following format:

permissions number_of_replicas userid groupid filesize modification_date modification_time filename

For a directory it returns list of its direct children as in Unix. A directory is listed as:

permissions userid groupid modification_date modification_time dirname

Example:

hdfs dfs -ls /user/hadoop/file1

Exit Code:

Returns 0 on success and -1 on error.

[hadoop@hello110 hadoop]$ hdfs dfs -help ls

-ls [-d] [-h] [-R] [<path> ...] :

??List the contents that match the specified file pattern. If path is not

??specified, the contents of /user/<currentUser> will be listed.（當hadoop下的user文件夾下沒有當前用戶的文件夾，則會提示沒有文件。）Directory entries

??are of the form:

????????permissions - userId groupId sizeOfDirectory(in bytes)

??modificationDate(yyyy-MM-dd HH:mm) directoryName

??and file entries are of the form:

????????permissions numberOfReplicas userId groupId sizeOfFile(in bytes)

??modificationDate(yyyy-MM-dd HH:mm) fileName ?????????????????????????????????????????????????????????????????

??-d ?Directories are listed as plain files. ????????????????????????????????????

??-h ?Formats the sizes of files in a human-readable fashion rather than a number

??????of bytes. ?????????????????????????????????????????????????????????????????

??-R ?Recursively list the contents of directories. ???????????

lsr

Usage:?hdfs dfs -lsr <args>

Recursive version of ls.

Note:?This command is deprecated. Instead use?hdfs dfs -ls -R

mkdir

Usage:?hdfs dfs -mkdir [-p] <paths>

Takes path uri's as argument and creates directories.

Options:

The -p option behavior is much like Unix mkdir -p, creating parent directories along the path.

Example:

hdfs dfs -mkdir /user/hadoop/dir1 /user/hadoop/dir2

hdfs dfs -mkdir hdfs://nn1.example.com/user/hadoop/dir hdfs://nn2.example.com/user/hadoop/dir

Exit Code:

Returns 0 on success and -1 on error.

moveFromLocal

Usage:?hdfs dfs -moveFromLocal <localsrc> <dst>

Similar to put command, except that the source localsrc is deleted after it's copied.

moveToLocal

Usage:?hdfs dfs -moveToLocal [-crc] <src> <dst>

Displays a "Not implemented yet" message.

mv

Usage:?hdfs dfs -mv URI [URI ...] <dest>。hdfs----->hdfs

Moves files from source to destination. This command allows multiple sources as well in which case the destination needs to be a directory. Moving files across file systems is not permitted.

Example:

hdfs dfs -mv /user/hadoop/file1 /user/hadoop/file2

hdfs dfs -mv hdfs://nn.example.com/file1 hdfs://nn.example.com/file2 hdfs://nn.example.com/file3 hdfs://nn.example.com/dir1

Exit Code:

Returns 0 on success and -1 on error.

put

Usage:?hdfs dfs -put <localsrc> ... <dst>

Copy single src, or multiple srcs from local file system to the destination file system. Also reads input from stdin and writes to destination file system.

hdfs dfs -put localfile /user/hadoop/hadoopfile

hdfs dfs -put localfile1 localfile2 /user/hadoop/hadoopdir

hdfs dfs -put localfile hdfs://nn.example.com/hadoop/hadoopfile

hdfs dfs -put - hdfs://nn.example.com/hadoop/hadoopfile?Reads the input from stdin.

Exit Code:

Returns 0 on success and -1 on error.

rm

Usage:?hdfs dfs -rm [-f] [-r|-R] [-skipTrash] URI [URI ...]

Delete files specified as args.

Options:

The -f option will not display a diagnostic message or modify the exit status to reflect an error if the file does not exist.

The -R option deletes the directory and any content under it recursively.

The -r option is equivalent to -R.

The -skipTrash option will bypass trash, if enabled, and delete the specified file(s) immediately. This can be useful when it is necessary to delete files from an over-quota directory.

Example:

hdfs dfs -rm hdfs://nn.example.com/file /user/hadoop/emptydir

Exit Code:

Returns 0 on success and -1 on error.

rmr

Usage:?hdfs dfs -rmr [-skipTrash] URI [URI ...]

Recursive version of delete.

Note:?This command is deprecated. Instead use?hdfs dfs -rm -r

setfacl

Usage:?hdfs dfs -setfacl [-R] [-b|-k?-m|-x <acl_spec>?<path>]|[--set <acl_spec> <path>]

Sets Access Control Lists (ACLs) of files and directories.

Options:

-b: Remove all but the base ACL entries. The entries for user, group and others are retained for compatibility with permission bits.

-k: Remove the default ACL.

-R: Apply operations to all files and directories recursively.

-m: Modify ACL. New entries are added to the ACL, and existing entries are retained.

-x: Remove specified ACL entries. Other ACL entries are retained.

--set: Fully replace the ACL, discarding all existing entries. The?acl_spec?must include entries for user, group, and others for compatibility with permission bits.

acl_spec: Comma separated list of ACL entries.

path: File or directory to modify.

Examples:

hdfs dfs -setfacl -m user:hadoop:rw- /file

hdfs dfs -setfacl -x user:hadoop /file

hdfs dfs -setfacl -b /file

hdfs dfs -setfacl -k /dir

hdfs dfs -setfacl --set user::rw-,user:hadoop:rw-,group::r--,other::r-- /file

hdfs dfs -setfacl -R -m user:hadoop:r-x /dir

hdfs dfs -setfacl -m default:user:hadoop:r-x /dir

Exit Code:

Returns 0 on success and non-zero on error.

setfattr

Usage:?hdfs dfs -setfattr?-n name [-v value] | -x name?<path>

Sets an extended attribute name and value for a file or directory.

Options:

-b: Remove all but the base ACL entries. The entries for user, group and others are retained for compatibility with permission bits.

-n name: The extended attribute name.

-v value: The extended attribute value. There are three different encoding methods for the value. If the argument is enclosed in double quotes, then the value is the string inside the quotes. If the argument is prefixed with 0x or 0X, then it is taken as a hexadecimal number. If the argument begins with 0s or 0S, then it is taken as a base64 encoding.

-x name: Remove the extended attribute.

path: The file or directory.

Examples:

hdfs dfs -setfattr -n user.myAttr -v myValue /file

hdfs dfs -setfattr -n user.noValue /file

hdfs dfs -setfattr -x user.myAttr /file

Exit Code:

Returns 0 on success and non-zero on error.

setrep

Usage:?hdfs dfs -setrep [-R] [-w] <numReplicas> <path>

Changes the replication factor of a file. If?path?is a directory then the command recursively changes the replication factor of all files under the directory tree rooted at?path.

Options:

The -w flag requests that the command wait for the replication to complete. This can potentially take a very long time.

The -R flag is accepted for backwards compatibility. It has no effect.

Example:

hdfs dfs -setrep -w 3 /user/hadoop/dir1

Exit Code:

Returns 0 on success and -1 on error.

stat

Usage:?hdfs dfs -stat URI [URI ...]

Returns the stat information on the path.

Example:

hdfs dfs -stat path

Exit Code: Returns 0 on success and -1 on error.

tail

Usage:?hdfs dfs -tail [-f] URI

Displays last kilobyte of the file to stdout.顯示最后10KB的內容。

Linux 滾動顯示ToolBox日志：tail?-1000f?start.log

Options:

The -f option will output appended data as the file grows, as in Unix.動態顯示新增的內容

Example:

hdfs dfs -tail pathname

Exit Code: Returns 0 on success and -1 on error.

test

Usage:?hdfs dfs -test -[ezd] URI

Options:

The -e option will check to see if the file exists, returning 0 if true.

The -z option will check to see if the file is zero length, returning 0 if true.

The -d option will check to see if the path is directory, returning 0 if true.

Example:

hdfs dfs -test -e filename

text

Usage:?hdfs dfs -text <src>

Takes a source file and outputs the file in text format. The allowed formats are zip and TextRecordInputStream.

cat

text

touchz

Usage:?hdfs dfs -touchz URI [URI ...]

Create a file of zero length.

Example:

hdfs dfs -touchz pathname

Exit Code: Returns 0 on success and -1 on error.