Question

I’m writing the following script:

v="1,pop";
sed "$v/d" dir/file1

It gives me this error:

char 3: unexpected `,'

How to solve this? Note: the value of $v cannot be controlled.

Answer 1

You are using sed in a wrong way.

$ v="1,pop";
$ cat file 
1,pop
Suku
JohnGeorge
stackoverflow
serverfault

$ sed '/'$v'/d' file
Suku
JohnGeorge
stackoverflow
serverfault

$ sed "/"$v"/d" file
Suku
JohnGeorge
stackoverflow
serverfault

If you want to substitute a bash variable inside sed, you need to surround it with quotes like I showed above. Also if you want to write modification to file, you need to use sed with -i.