CODEWITHSUNDEEP
regexbashshellsed
Brave
Brave

Reputation: 177

White spaces in sed search string

I want to substitute a String from a file which is:

#     - "server1"

My first attempt was something like this:

sed -i 's/#\     -\ "\server1"\.*/ChangedWord/g' file

But I get an error if I try it like this.

So there is to be another way to handle whitespaces, I guess I have to use \s or [[:space:]]. But for some how I am not able to make it work.

Upvotes: 0

Views: 4420

Answers (3)

Brave
Brave

Reputation: 177

The actual fault was the missing escaping from the double quotes:

 ssh -i file root@IP sed 's/^#[[:space:]]*-[[:space:]]*\"server1\".*/ChangedWord/' file

That did it for me. Thanks for all your support

Upvotes: 1

fedorqui
fedorqui

Reputation: 289855

I think you are complicating the expression too much. This should be enough:

sed 's/^#[[:space:]]*-[[:space:]]*"server1".*/ChangedWord/' file

It looks for those lines starting with # followed by 0 to n spaces, then "server1" and then anything. In such case, it replaces the line with ChangedWord.

Note I am using [[:space:]] to match the spaces, since it is a more compatible way (thanks Tom Fenech in comments).

Note also there is no need to use g in the sed expression, because the pattern can occur just once per line.

Test

$ cat a
hello
#     - "server1"
hello#     - "server1"
$ sed 's/^#[[:space:]]*-[[:space:]]*"server1".*/ChangedWord/' a
hello
ChangedWord
hello#     - "server1"

Upvotes: 5

Likeyn
Likeyn

Reputation: 293

rghome is right, you don't need those backslashes in front of spaces as the expression is wrapped in quotes. In fact, they're causing the error: sed is telling you that \<Space> is not a valid option. Just remove them and it should work as expected:

sed -i 's/#     - "server1"/ChangedWord/' file

Upvotes: 0

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