how to replace a line in file with blank line

Shell Programming and Scripting
1

Hi

I nned cmd to which will help me to replace a line in file with blank line
e.g.
file1
a
b
c
d
e

after running cmd I shud get
file1
b
c
d
e

2

You example seems to have deleted the row with "a". This deletes any row that starts with lowercase a

sed '/^a'/d' file1 > tmp
mv tmp file1
3

If I m getting word from some script whose value is $i, where I don't the word likewise here where word a how to approach it ?

4

I did not get it , what your question is ?.

5 
grep -v $i file > new_file
6

superb thxs danmero ,