Rewrite scr of all images - php

Question

I change hosting and some of images are linked to old hosting account and have 403 status. How can I rewrtite all of their src in functions.php?
For example I have image with scr https://dsweb.su/wp-content/uploads/2018/06/Main_demo.png and I want to change first part so path will be https://artweb.su/wp-content/uploads/2018/06/Main_demo.png. All images that have this part https://dsweb.su/ should be changed to have this part instead https://artweb.su/. I think I can do this with htaccess rewriting but I don't know how to do this.

Answer 1

If you have access to SSH, the easiest way is to use the official WP CLI's search-replace command. Installation instructions are at the previous link and are system-dependent, so I won't go into them here.
First, make sure that you have a database backup, and that you know how to restore it, just in case. (I do this process several times a week but at the end of the day, it is your database and I'm just a random stranger on the internet.)
Next, cd into your site's root and we'll be running the following command. The first parameter (after search-replace) is the original string and the second is the new string. Keep reading my notes below on that before making any changes. The third parameter, --recurse-objects (which actually appears to be the default now, but I still manually type it) handles serialized data which is very common in WordPress. The fourth parameter, --all-tables, tells the searcher to use every table in the database, even if it isn't registered with WordPress. It is pretty rare to not use this flag. The last parameter, --dry-run, means "don't actually do it, just test and tell me the results.
wp search-replace "https://dsweb.su" "https://artweb.su" --recurse-objects --all-tables --dry-run
Once that completes, take note of the last message which will be something like:
Success: 1,234 replacements to be made.
If it says 0 replacements, the string we are searching for could not be found. You'll need to handle that or post something here.
If it says an actual number, you can re-run the command removing the --dry-run parameter, and you should be all set.
A note on the first two parameters
The first two parameters are NOT URLs and they are NOT domains! I cannot stress this enough. They are just arbitrary strings that happen to look like URLs.
If your database also has your domain with a WWW in the front, such as https://www.dsweb.su, that will not be found. Similarly, if your database has URLs that are not secure, such as http://dsweb.su, those won't be found. Because of this, I recommend running the search and replace a couple of times.
# secure, no www
wp search-replace "https://dsweb.su" "https://artweb.su" --recurse-objects --all-tables --dry-run
# secure, www
wp search-replace "https://www.dsweb.su" "https://artweb.su" --recurse-objects --all-tables --dry-run
# not secure, no www
wp search-replace "http://dsweb.su" "https://artweb.su" --recurse-objects --all-tables --dry-run
# not secure, www
wp search-replace "http://www.dsweb.su" "https://artweb.su" --recurse-objects --all-tables --dry-run
For the replacement, always use the same string, we're only changing what is searched for. These examples all include the --dry-run parameter which I always recommend so that you know what it is about to do.
Your opinion of your site's domain isn't important, by the way. You'd be surprised what you can find in there. Somehow, some way, these extra versions get stuck in there.
There's two other potential cases that can crop up, but one is pretty rare but the other is not uncommon.
The rare one is a protocol-less URL //example.com, but that's easy to search for.
The not uncommon one is a regular domain, example.com. You can search for that, but remember that email addresses start with that as well, so you have to be very careful when doing that replacement, and I really don't recommend running it.