Output a file to itself ??

[dbeez]

Hi,

I am trying to make the output of a command on a file, feed itself into the same file ... in other words

sed -e -n 's/text//g' file1 > file1

... instead of getting an updated file1, containing only the new sorted text. I get a blank file1

I guess this must be a fairly simple question ... anyone have any ideas ???

 

[KenCunningham]

sed doesn't work like that (as you've found out). Best thing to do is output to a temp file and then rename that to your original at the end.

 

[feherke]

Hi

GNU [tt]sed[/tt] version 4.1.2 :

-i[SUFFIX], --in-place[=SUFFIX] edit files in place (makes backup if extension supplied)

sed -i 's/text//g' file1

By the way. If you put -n, without a [tt]p[/tt] command of course your output file will be empty.

Feherke.

http://rootshell.be/~feherke/

 

[KenCunningham]

Interesting feherke, thanks.

 

[PHV]

One portable way:
echo "1,\$s/text//g\nw" | ed -s file1

Hope This Helps, PH.
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