deleting N lines of many files

deleting N lines of many files

[Fabio Zyserman]

Hi all,

I have about eighty directories,
called data-nn, where nn=00,01,02,....
in each of these directories I have
among others, an (ascii) data file with many thousends
lines. This data file has the same name in all
directories.

I would like to know if it is possible,
via a bash script, to delete the first N
lines in this data file in all directories.
The modified file can overwrite the old one.

Many thanks in advance,

Fabio Zyserman

Re: deleting N lines of many files

[zavandi]

Fabio Zyserman <zyserman@fcaglp.unlp.edu.ar> wrote:
> I have about eighty directories,
> called data-nn, where nn=00,01,02,....
> in each of these directories I have
> among others, an (ascii) data file with many thousends
> lines. This data file has the same name in all
> directories.
> 
> I would like to know if it is possible,
> via a bash script, to delete the first N
> lines in this data file in all directories.
> The modified file can overwrite the old one.

Maybe you want something along the lines of (not tested!):

for i in `seq -w 0 80`; do sed -i "1,${N}d" $i/filename; done

Re: deleting N lines of many files

[Yu Chen]

you can try this, in the parent directory of all these directories, type

find ./ -name "DATA_File_name" -exec sed "1,${N}d" {} > NEW_file_name \;

should be enough, you will have both new and old files, after 
confirmation, you can move new ones to overwrite old ones.

Chen

On Fri, 17 Dec 2004, Fabio Zyserman wrote:

> Hi all,
>
> I have about eighty directories,
> called data-nn, where nn=00,01,02,....
> in each of these directories I have
> among others, an (ascii) data file with many thousends
> lines. This data file has the same name in all
> directories.
>
> I would like to know if it is possible,
> via a bash script, to delete the first N
> lines in this data file in all directories.
> The modified file can overwrite the old one.
>
> Many thanks in advance,
>
> Fabio Zyserman
>
> -
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===========================================
Yu Chen
Howard Hughes Medical Institute
Chemistry Building, Rm 182
University of Maryland at Baltimore County
1000 Hilltop Circle
Baltimore, MD 21250

phone: 	(410)455-6347 (primary)
 	(410)455-2718 (secondary)
fax: 	(410)455-1174
email: 	chen@hhmi.umbc.edu
===========================================

Re: deleting N lines of many files

[Jeff Woods]

At 12/17/2004 09:33 AM -0300, Fabio Zyserman wrote:
>I have about eighty directories, called data-nn, where nn=00,01,02,.... in 
>each of these directories I have among others, an (ascii) data file with 
>many thousends lines. This data file has the same name in all directories.
>
>I would like to know if it is possible, via a bash script, to delete the 
>first N lines in this data file in all directories. The modified file can 
>overwrite the old one.

Something like:

for file in data-[0-9][0-9]/filename
do
temp="${file}-temp"
tail +N "$file" > "$temp" && mv "$temp" "$file"
done

--
Jeff Woods <kazrak+kernel@cesmail.net>