Hello,
I would like to extract a line from every 3 lines from a file.
the files looks like

1.1
1.2
1.3
1.4
1.5
1.6

I only want to extract 1.1 and 1.4 and put them in a different file,
thanks for
your !

Zhengquan

zhengquan scrisse:

> I would like to extract a line from every 3 lines from a file.


With GNU sed:


sed -n '1~3' infile > outfile

On 5/2/2008 4:40 PM, zhengquan wrote:
> Hello,
> I would like to extract a line from every 3 lines from a file.
> the files looks like
>
> 1.1
> 1.2
> 1.3
> 1.4
> 1.5
> 1.6
>
> I only want to extract 1.1 and 1.4 and put them in a different file,
> thanks for
> your !
>
> Zhengquan

awk '!((NR-1)%3)' file > newfile

Ed.

On 5/2/2008 4:59 PM, mallin.shetland wrote:
> zhengquan scrisse:
>
>
>>I would like to extract a line from every 3 lines from a file.
>
>
>
> With GNU sed:
>
>
> sed -n '1~3' infile > outfile

ITYM:

sed -n '1~3p' infile > outfile

Ed.

On May 2, 5:08 pm, Ed Morton <mor...@lsupcaemnt.com> wrote:
> On 5/2/2008 4:59 PM, mallin.shetland wrote:
>
> > zhengquan scrisse:
>
> >>I would like to extract a line from every 3 lines from a file.
>
> > With GNU sed:
>
> > sed -n '1~3' infile > outfile
>
> ITYM:
>
> sed -n '1~3p' infile > outfile
>
> Ed.

Thank you guys!

Zhengquan

On Friday 2 May 2008 23:59, mallin.shetland wrote:

> zhengquan scrisse:
>
>> I would like to extract a line from every 3 lines from a file.
>
>
> With GNU sed:
>
>
> sed -n '1~3' infile > outfile


You need to print the line:

sed -n '1~3p' infile > outfile

and, you can do the same just as easily with standard sed:

sed -n '1,${p;n;n}' infile > outfile

--
D.