shell script: File Manipulation

simon_qwl · 10-27-2005, 04:35 AM

hi,everyone!i want write a shell script which can delete certain line in a file based on the user's selection.
user will give the string pattern in command line and the shell script will delete any matched lines in a file.i tried to use 'sed' to achieve this,however sed command considers the '$1' is a string pattern rather than a varaible. it will search the file with string pattern '$1'.
thanks a lot for any helps!

homey · 10-27-2005, 05:10 AM

Hi,
Something like this ...

Code:

#!/bin/bash

echo
echo ""
echo "Enter string: "
read info
echo

file="/home/file.txt"
stuff=`cat $file | grep -n "$info" | cut -d: -f1`
cat $file | sed -e ''$stuff'd'

eddiebaby1023 · 10-29-2005, 03:40 PM

Quote:

Code:

stuff=`cat $file | grep -n "$info" | cut -d: -f1`
cat $file | sed -e ''$stuff'd'

Please don't be a process hog (and your quoting leaves a bit to be desired ;-) ):

Code:

stuff=`grep -n "$info" $file | cut -d: -f1`
sed -e "/$stuff/d" $file

Simon, if you use double quotes around the $1, you'll find sed will work perfectly.

Code:

sed "/$1/d" file

Learn how to use quotes properly and you'll find scripting becomes much easier.