Shell Programming and Scripting

Hi gurus,

i'm trying to remove a number of lines from a large file using the following command:

sed '1,5000d' oldfile > newfile

Somehow the lines in the old file are not deleted...

Am I doing this wrongly? Any suggestions?

Thanks!

wee

What do you expect ?
If you want to delete in original file read man sed for -i option.

like this:

Code:

sed -i '1,5000 d' oldfile

from the GNU sed manual:

Code:

       -i[SUFFIX], --in-place[=SUFFIX]

              edit files in place (makes backup if extension supplied)

hey gurus...

perhaps i did not make myself clear...

well i have this really huge file which i cannot open up using vi (due to the constraint in which /tmp buffer could not hold)

so i need to extract out the oldest information within the file (say maybe the first 10000 lines) and pipe out to another file while at the same time the 10000 lines will be removed from the old file.

which is why i'm using sed to do it but somehow it's not matching my ideal results...

please advise. thanks.

wee

first check wthether you have latest version of sed which comes with -i option
you can check this in man page if you have that you can do

Code:

sed -i '1,10000d' huge_file > temp_file

if you don't have the -i option

Code:

sed -n '1,10000p' huge_file > file1
sed -n '10001,$p' huge_file > temp_file
cat temp_file >huge_file

sorry i dont have the -i option for sed...probably this is the older version.

will try out the other option.

update later. thanks.

wee

hi what does $p stands for? variable?

somehow it does not seem to do what i'm expected it to do...

supposed i have this file with 200000 lines in it, so what i'm trying to do is to remove the first 100000 lines and pipe it to another file so that i can use vi to open the original file.

hmm...sounds complicated?

thanks gurus.

wee