Replace string using sed command

bloodstreetboy · 07-05-2012, 07:47 AM

I want to replace a particular data in text file.
Ex- a1@b44, a2@b90, a3@b76 and there are several entries like this between 1 to 100. I mean maximum number is 100. i.e. a100@b73 or a7@b100.
I want to add .com with every entry.
It means a1@b44 should be a1@b44.com
a2@b90 should be a2@b90.com
a3@b76 should be a3@b76.com
a100@b73 should be a100@b73.com
a7@b100 should be a7@b100.com

Please help. If you can give solution using sed, it will be greatest help from your side.
Ask anything if I am not able to explain completely.

sycamorex · 07-05-2012, 08:18 AM

If there's only one entry per line and nothing else, you could do:

Code:

sed 's/$/.com/' file.txt

If that's not the case, you'll have to provide more details. Ideally, a sample of the input file.

sycamorex · 07-05-2012, 08:23 AM

Alternatively, this might be a better solution. Here there can be more text after the email address.

Code:

sed 's/@.[^ ]*/&.com/g' aba.txt

Still, to be sure you'd have to provide a sample of the file.

bloodstreetboy · 07-05-2012, 09:13 AM

Thanks for the perfect solution.
No, it was not the only string in line. There are many words before and after the particular string.
But your second solution is fit for my text file.
I want to ask something. If we put or do not put backslash before @, it does not affect the result. why? Is @ not the meta character?
If we remove [^ ] from the command. what does it mean?
sed 's/@.*/&.com/g' aba.txt
Because it is giving the correct result too. Does it mean, single and multiple occurrences of character @.
Then how will we write that single and multiple occurrences of other characters after @?

sycamorex · 07-05-2012, 09:52 AM

Quote:

want to ask something. If we put or do not put backslash before @, it does not affect the result. why? Is @ not the meta character?

I don't think @ has any special meaning here.

Glad it worked for you.

Quote:

If we remove [^ ] from the command. what does it mean?
sed 's/@.*/&.com/g' aba.txt
Because it is giving the correct result too. Does it mean, single and multiple occurrences of character @.

If there are other characters and spaces after the email address, it can't give you the same result.

@.* means @ and 0 or more of any character

@.[^ ]* means @ and 0 or more of any character until you reach a blank space

Quote:

Then how will we write that single and multiple occurrences of other characters after @?

Again, you must be more specific. I have no idea what you mean.

Please, provide at least one line of the actual file. Otherwise, we might be wasting a lot of time trying to guess what you mean. If you can please provide examples of those multiple occurrences as well so that it's clear what you mean.

bloodstreetboy · 07-06-2012, 02:11 AM

Quote:

Originally Posted by sycamorex

If there are other characters and spaces after the email address, it can't give you the same result.
@.* means @ and 0 or more of any character
@.[^ ]* means @ and 0 or more of any character until you reach a blank space

Thanks for the specification.Now I got difference between @.[^ ]* & @.*
Actually I was confused between occurrences of same characters and any character after the particular character.
Ex- @@@@ - four occurrences of same character.
@.5yBW - more than one occurrence of any character after @.

The command you gave was perfect for my issue.

Code:

sed 's/@.[^ ]*/&.com/g' untitled.csv

But if we remove [^ ], it adds the .com at last of the line, the same result given by your first command.

I am not able to give my complete text file but it is exactly like this.

Code:

InfoKey: a15@b74 Creator
InfoValue: LaTeX  a44@b89 with hyperref package
InfoKey: a1@b7 Producer
InfoValue: dvips + a13@b78 GNU Ghostscript 7.07
NumberOfPages: a22@b88 190
BookmarkTitle:  Table of Contents
BookmarkLevel: a42@b39 1
BookmarkPageNumber: a92@b68 3 Table of Contents

sycamorex · 07-06-2012, 03:03 PM

Quote:

But if we remove [^ ], it adds the .com at last of the line, the same result given by your first command.

That's correct. It'll add the suffix .com to the end of a line.

I guess the line below is your question:

Quote:

Then how will we write that single and multiple occurrences of other characters after @?

Not sure what you mean by that? Write where? Do you mean match? See below:

Code:

InfoKey: a15@b74 Creator
InfoValue: LaTeX  a44@b89 with hyperref package
InfoKey: a1@b7 Producer
InfoValue: dvips + a13@b78 GNU Ghostscript 7.07
NumberOfPages: a22@b88 190
BookmarkTitle:  Table of Contents
BookmarkLevel: a42@b39 1
BookmarkPageNumber: a92@b68 3 Table of Contents
Boodafa adf: a08@b100 dfadaadfa; afdad df
dadfa adfaf a09@b1 blah blahblah

Code:

sed -n 's/.*@\(b[0-9][0-9]*\).*/\1/p' file
b74
b89
b7
b78
b88
b39
b68
b100
b1

It also works for strings with .com added.

Hope that helps.