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Posted to user@hadoop.apache.org by Chengi Liu <ch...@gmail.com> on 2013/08/29 22:35:35 UTC
copy files from hdfs to local fs
Ok,
A very stupid question...
I have a large file in
/user/input/foo.txt
I want to copy first 100 lines from this location to local filesystem...
And the data is very sensitive so i am bit hesistant to experiment.
What is the right way to copy sample data from hdfs to local fs.
RE: copy files from hdfs to local fs
Posted by java8964 java8964 <ja...@hotmail.com>.
What's wrong by using old Unix pipe?
hadoop fs -cat /user/input/foo.txt | head -100 > local_file
Date: Thu, 29 Aug 2013 13:50:37 -0700
Subject: Re: copy files from hdfs to local fs
From: chengi.liu.86@gmail.com
To: user@hadoop.apache.org
tail will work as well.. ??? but i want to extract just (say) n lines out of this file?
On Thu, Aug 29, 2013 at 1:43 PM, Kim Chew <kc...@gmail.com> wrote:
hadoop fs -copyToLocal
or
hadoop fs -get
It copies the whole file and won't be able just to copy part of the file, what is interesting is there is a "tail" command but no "head".
Kim
On Thu, Aug 29, 2013 at 1:35 PM, Chengi Liu <ch...@gmail.com> wrote:
Ok,
A very stupid question...
I have a large file in
/user/input/foo.txt
I want to copy first 100 lines from this location to local filesystem...
And the data is very sensitive so i am bit hesistant to experiment.
What is the right way to copy sample data from hdfs to local fs.
RE: copy files from hdfs to local fs
Posted by java8964 java8964 <ja...@hotmail.com>.
What's wrong by using old Unix pipe?
hadoop fs -cat /user/input/foo.txt | head -100 > local_file
Date: Thu, 29 Aug 2013 13:50:37 -0700
Subject: Re: copy files from hdfs to local fs
From: chengi.liu.86@gmail.com
To: user@hadoop.apache.org
tail will work as well.. ??? but i want to extract just (say) n lines out of this file?
On Thu, Aug 29, 2013 at 1:43 PM, Kim Chew <kc...@gmail.com> wrote:
hadoop fs -copyToLocal
or
hadoop fs -get
It copies the whole file and won't be able just to copy part of the file, what is interesting is there is a "tail" command but no "head".
Kim
On Thu, Aug 29, 2013 at 1:35 PM, Chengi Liu <ch...@gmail.com> wrote:
Ok,
A very stupid question...
I have a large file in
/user/input/foo.txt
I want to copy first 100 lines from this location to local filesystem...
And the data is very sensitive so i am bit hesistant to experiment.
What is the right way to copy sample data from hdfs to local fs.
RE: copy files from hdfs to local fs
Posted by java8964 java8964 <ja...@hotmail.com>.
What's wrong by using old Unix pipe?
hadoop fs -cat /user/input/foo.txt | head -100 > local_file
Date: Thu, 29 Aug 2013 13:50:37 -0700
Subject: Re: copy files from hdfs to local fs
From: chengi.liu.86@gmail.com
To: user@hadoop.apache.org
tail will work as well.. ??? but i want to extract just (say) n lines out of this file?
On Thu, Aug 29, 2013 at 1:43 PM, Kim Chew <kc...@gmail.com> wrote:
hadoop fs -copyToLocal
or
hadoop fs -get
It copies the whole file and won't be able just to copy part of the file, what is interesting is there is a "tail" command but no "head".
Kim
On Thu, Aug 29, 2013 at 1:35 PM, Chengi Liu <ch...@gmail.com> wrote:
Ok,
A very stupid question...
I have a large file in
/user/input/foo.txt
I want to copy first 100 lines from this location to local filesystem...
And the data is very sensitive so i am bit hesistant to experiment.
What is the right way to copy sample data from hdfs to local fs.
RE: copy files from hdfs to local fs
Posted by java8964 java8964 <ja...@hotmail.com>.
What's wrong by using old Unix pipe?
hadoop fs -cat /user/input/foo.txt | head -100 > local_file
Date: Thu, 29 Aug 2013 13:50:37 -0700
Subject: Re: copy files from hdfs to local fs
From: chengi.liu.86@gmail.com
To: user@hadoop.apache.org
tail will work as well.. ??? but i want to extract just (say) n lines out of this file?
On Thu, Aug 29, 2013 at 1:43 PM, Kim Chew <kc...@gmail.com> wrote:
hadoop fs -copyToLocal
or
hadoop fs -get
It copies the whole file and won't be able just to copy part of the file, what is interesting is there is a "tail" command but no "head".
Kim
On Thu, Aug 29, 2013 at 1:35 PM, Chengi Liu <ch...@gmail.com> wrote:
Ok,
A very stupid question...
I have a large file in
/user/input/foo.txt
I want to copy first 100 lines from this location to local filesystem...
And the data is very sensitive so i am bit hesistant to experiment.
What is the right way to copy sample data from hdfs to local fs.
Re: copy files from hdfs to local fs
Posted by Chengi Liu <ch...@gmail.com>.
tail will work as well.. ??? but i want to extract just (say) n lines out
of this file?
On Thu, Aug 29, 2013 at 1:43 PM, Kim Chew <kc...@gmail.com> wrote:
> hadoop fs -copyToLocal
> or
> hadoop fs -get
>
> It copies the whole file and won't be able just to copy part of the file,
> what is interesting is there is a "tail" command but no "head".
>
> Kim
>
>
> On Thu, Aug 29, 2013 at 1:35 PM, Chengi Liu <ch...@gmail.com>wrote:
>
>> Ok,
>>
>> A very stupid question...
>>
>> I have a large file in
>>
>> /user/input/foo.txt
>>
>> I want to copy first 100 lines from this location to local filesystem...
>>
>> And the data is very sensitive so i am bit hesistant to experiment.
>>
>> What is the right way to copy sample data from hdfs to local fs.
>>
>>
>
Re: copy files from hdfs to local fs
Posted by Chengi Liu <ch...@gmail.com>.
tail will work as well.. ??? but i want to extract just (say) n lines out
of this file?
On Thu, Aug 29, 2013 at 1:43 PM, Kim Chew <kc...@gmail.com> wrote:
> hadoop fs -copyToLocal
> or
> hadoop fs -get
>
> It copies the whole file and won't be able just to copy part of the file,
> what is interesting is there is a "tail" command but no "head".
>
> Kim
>
>
> On Thu, Aug 29, 2013 at 1:35 PM, Chengi Liu <ch...@gmail.com>wrote:
>
>> Ok,
>>
>> A very stupid question...
>>
>> I have a large file in
>>
>> /user/input/foo.txt
>>
>> I want to copy first 100 lines from this location to local filesystem...
>>
>> And the data is very sensitive so i am bit hesistant to experiment.
>>
>> What is the right way to copy sample data from hdfs to local fs.
>>
>>
>
Re: copy files from hdfs to local fs
Posted by Chengi Liu <ch...@gmail.com>.
tail will work as well.. ??? but i want to extract just (say) n lines out
of this file?
On Thu, Aug 29, 2013 at 1:43 PM, Kim Chew <kc...@gmail.com> wrote:
> hadoop fs -copyToLocal
> or
> hadoop fs -get
>
> It copies the whole file and won't be able just to copy part of the file,
> what is interesting is there is a "tail" command but no "head".
>
> Kim
>
>
> On Thu, Aug 29, 2013 at 1:35 PM, Chengi Liu <ch...@gmail.com>wrote:
>
>> Ok,
>>
>> A very stupid question...
>>
>> I have a large file in
>>
>> /user/input/foo.txt
>>
>> I want to copy first 100 lines from this location to local filesystem...
>>
>> And the data is very sensitive so i am bit hesistant to experiment.
>>
>> What is the right way to copy sample data from hdfs to local fs.
>>
>>
>
Re: copy files from hdfs to local fs
Posted by Chengi Liu <ch...@gmail.com>.
tail will work as well.. ??? but i want to extract just (say) n lines out
of this file?
On Thu, Aug 29, 2013 at 1:43 PM, Kim Chew <kc...@gmail.com> wrote:
> hadoop fs -copyToLocal
> or
> hadoop fs -get
>
> It copies the whole file and won't be able just to copy part of the file,
> what is interesting is there is a "tail" command but no "head".
>
> Kim
>
>
> On Thu, Aug 29, 2013 at 1:35 PM, Chengi Liu <ch...@gmail.com>wrote:
>
>> Ok,
>>
>> A very stupid question...
>>
>> I have a large file in
>>
>> /user/input/foo.txt
>>
>> I want to copy first 100 lines from this location to local filesystem...
>>
>> And the data is very sensitive so i am bit hesistant to experiment.
>>
>> What is the right way to copy sample data from hdfs to local fs.
>>
>>
>
Re: copy files from hdfs to local fs
Posted by Kim Chew <kc...@gmail.com>.
hadoop fs -copyToLocal
or
hadoop fs -get
It copies the whole file and won't be able just to copy part of the file,
what is interesting is there is a "tail" command but no "head".
Kim
On Thu, Aug 29, 2013 at 1:35 PM, Chengi Liu <ch...@gmail.com> wrote:
> Ok,
>
> A very stupid question...
>
> I have a large file in
>
> /user/input/foo.txt
>
> I want to copy first 100 lines from this location to local filesystem...
>
> And the data is very sensitive so i am bit hesistant to experiment.
>
> What is the right way to copy sample data from hdfs to local fs.
>
>
Re: copy files from hdfs to local fs
Posted by Kim Chew <kc...@gmail.com>.
hadoop fs -copyToLocal
or
hadoop fs -get
It copies the whole file and won't be able just to copy part of the file,
what is interesting is there is a "tail" command but no "head".
Kim
On Thu, Aug 29, 2013 at 1:35 PM, Chengi Liu <ch...@gmail.com> wrote:
> Ok,
>
> A very stupid question...
>
> I have a large file in
>
> /user/input/foo.txt
>
> I want to copy first 100 lines from this location to local filesystem...
>
> And the data is very sensitive so i am bit hesistant to experiment.
>
> What is the right way to copy sample data from hdfs to local fs.
>
>
Re: copy files from hdfs to local fs
Posted by Kim Chew <kc...@gmail.com>.
hadoop fs -copyToLocal
or
hadoop fs -get
It copies the whole file and won't be able just to copy part of the file,
what is interesting is there is a "tail" command but no "head".
Kim
On Thu, Aug 29, 2013 at 1:35 PM, Chengi Liu <ch...@gmail.com> wrote:
> Ok,
>
> A very stupid question...
>
> I have a large file in
>
> /user/input/foo.txt
>
> I want to copy first 100 lines from this location to local filesystem...
>
> And the data is very sensitive so i am bit hesistant to experiment.
>
> What is the right way to copy sample data from hdfs to local fs.
>
>
Re: copy files from hdfs to local fs
Posted by Kim Chew <kc...@gmail.com>.
hadoop fs -copyToLocal
or
hadoop fs -get
It copies the whole file and won't be able just to copy part of the file,
what is interesting is there is a "tail" command but no "head".
Kim
On Thu, Aug 29, 2013 at 1:35 PM, Chengi Liu <ch...@gmail.com> wrote:
> Ok,
>
> A very stupid question...
>
> I have a large file in
>
> /user/input/foo.txt
>
> I want to copy first 100 lines from this location to local filesystem...
>
> And the data is very sensitive so i am bit hesistant to experiment.
>
> What is the right way to copy sample data from hdfs to local fs.
>
>