When i grep a file and store it in a file it is storing as a zero byte file any way to avoid that.....
Post your command. There is no way to give an accurate answer without that. Here is a thought though. Are you doing something like:
grep "something" arunkumar.txt > arunkumar.txt
This will truncate the file first and then run the grep on that file; which will obviously output a zero byte file.
Thank you but i want to do grep a same file and save in that file is that possible ?? please give some idea
grep pattern filename >> filename
this would append the pattern search into the filename,
is that you want?
Not with grep. However you could do it with sed if you are on a gnu system.
try this command
grep "expression" filename | & tee log
This work for all command , one output will redirected to standard output which is screen and another in the file name log.
rajesh
Two solutions ...
With sed (2 steps):
sed -n '/expression/p' filename > tempfile
mv tempfile filename
With perl (1 step) :
perl -n -i -e 'print if /expression/' filename
Jean-Pierre.