sed: -e expression #1, char 1: unknown command: `''

Question

I have already read a similar question, but there is no solution to my problem.

I want to delete some line in some file I use sed in the script this is the code.

line="this"
del='echo "'/"$line"/d'"' #it's a AltGr+7 on AZERTY keyboard but for readability of the code I use '
sed -i $del /home/example/fic.txt

I also try:

line="this"
del='echo "/"$line"/d"'
sed $del /home/example/fic > /home/example/fic

but I have the same error:

sed: -e expression #1, char 1: unknown command: `''

Solution

Try this,

line="this"
del=`echo "/"$line"/d"`
sed $del /home/example/fic > /home/example/fic

In your code, you are single quotes while assigning value to variable del. which will consider as a static string rather than executing it. We can use backticks or $() to execute it.

better way,

line="this"
sed -i "/$line/d" /home/example/fic

• -i edit in line.

Comments

[Tsifi Stifen]

Thank you for your answer, I already note in the comment, I don't know how to add ` in the code and I use ' only for example. I use ` in my script but it doesn't work :)

[Tsifi Stifen]

it' s work when I use directly sed "/$line/d" /home/example/fic Thank you :)

[Tsifi Stifen]

thank you it's OK know :)

[Siva]

hope u have not declared line

[Angel Todorov]

Use $(...) instead of backticks -- easier to see that it's different from single quote.