-2

I tried below command in my script and got error,

sed -i -e 's/\(dataTable\)/$replace \1/' file.txt

Error Message,

sed: -e expression #1, char 22: unknown option to `s'

Please help me in correcting the command to avoid error.

Thanks!

Kusalananda
  • 333,661
Regnard Viven
  • 1
  • 1
    I can't get that error, not on Linux nor on macOS. Character 22 would also be in the middle of the word replace, so it doesn't look like it would be taken as an option to s, like the x in s/.../.../x would. You may want to double-check that's the actual command you used. – ilkkachu Aug 25 '21 at 20:55
  • 3
    ... I can imagine it happening if you'd used double quotes rather than single quotes, and $replace contains a forward slash character (like replace=some/thing) – steeldriver Aug 25 '21 at 22:03

1 Answers1

1

I'm assuming that you are actually using double quotes around your sed expression rather than single quotes, or you would not get that error.

I'm also assuming that you are using a string in your $replace value that contains a slash (/). When the variable is expanded, its value is injected into the sed statement and since it contains a slash, it breaks the syntax for the s/// command.

You can solve this by changing the delimiter that you use in the sed command to some other character that is not present in $replace.

If you choose @, for example,

sed -i -e 's@\(dataTable\)@'"$replace"' \1@' file.txt

Note that you will still have issue is your $replace string contains the substrings \x (where x is any digit), or & (which would be replaced by the part of the string that matches the expression). You will have to escape these special strings.

See e.g.

As a special case, if you plan on replacing a single whole line with new (static) contents, you could do that as follows:

printf '%s\n' "$replace" | sed -e '/some pattern/{ r /dev/stdin' -e 'd; }' file.txt

This finds the line matching /some pattern/ and then reads in the replacement text from standard input (from printf). It then deletes the old line.

Kusalananda
  • 333,661