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: `''

Siva · Accepted Answer · 2019-08-07T11:41:03.260

1

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.

edited Aug 07 '19 at 11:41

answered Aug 07 '19 at 11:35

Siva

9,077

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 Aug 07 '19 at 11:56
it' s work when I use directly sed "/$line/d" /home/example/fic Thank you :) – Tsifi Stifen Aug 07 '19 at 12:15
Now when I call the scrit which contente sed -i "/$line/d" /home/example/fic I Have this error: sed: -e expression #1, char 0: no previous regular expression – Tsifi Stifen Aug 07 '19 at 12:44
thank you it's OK know :) – Tsifi Stifen Aug 07 '19 at 12:51
hope u have not declared line – Siva Aug 07 '19 at 12:52
2

Use $(...) instead of backticks -- easier to see that it's different from single quote. – glenn jackman Aug 07 '19 at 23:15

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

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