Replacing string having forward slash in sed

Question

I wish to replace

x.y.z.zz=/a/b/c/d/

with

x.y.z.zz=/a/b/e/d/

i know x.y.z.zz in advance.I also know the line number in advance. I have tried this

sed  "11s/.*/x.y.z.zz=\/a\/b\/e\/d\/" filename

but this is giving error. Is there a better way to directly search and replace the string ?

Answer 1

You can just replace c with e if you know your input will always have "x.y.z.zz=/a/b/c/d".
e.g. just executing sed s/c/e/
will just replace c with e in the line. Also, you don't need to change the complete line always. You can just change a character or a word in the text.

Additionally, if a line contains more than one occurrence of character/word, this command will only change the first one
e.g. if input string is x.y.z.zz=/a/b/c/d/c, executing sed s/c/e/ will have output x.y.z.zz=/a/b/e/d/c

If all the occurrences need to be changed g (global) needs to be added in sed command
e.g. sed s/c/e/g will give output x.y.z.zz=/a/b/e/d/e

If sed needs to be executed only for a particular line, line number shall be mentioned in the sed command itself, as done in the question.

This is the link (http://www.grymoire.com/Unix/Sed.html), I always refer when in question with sed

Answer 2

sed replaces by using the sed 's/pattern/replacement/' syntax. In your case, you were missing the last /. So by saying this it will work:

sed '11s/.*/x.y.z.zz=\/a\/b\/e\/d\//' file
                                   ^

However, it may be cleaner to use another delimiter, so that the syntax is more clear. What about #? (It can also be ~, _, etc.):

sed '11s#.*#x.y.z.zz=/a/b/e/d/#' file

Test

$ cat a
a
x.y.z.zz=/a/b/c/d/
b
c

Let's replace line 2:

$ sed '2s#.*#x.y.z.zz=/a/b/e/d/#' a
a
x.y.z.zz=/a/b/e/d/
b
c