PHP: How to replace a segment of a string with some random text from a list

Question

I have a string with a URL in it and I wish to find and replace a predictable part of the URL with something else.

Basically, how to randomise a choice of subdomain.

For example, $file contains: https://url.foo.com/w_Path/File.doc how do I check if $file contains url.foo.com, and if so, replace the url.foo.com portion with either differentsubdomain.foo.com or anotherplace.foo.com or someotherplace.foo.com?

Input:

$file = "https://url.foo.com/w_Path/SomeFile.ext";
$params['file'] = $file

Desired output:

$file = "https://url.foo.com/w_Path/SomeFile.ext";
 // list of subdomains = "differentsubdomain", "anotherplace", "someotherplace";
 // find 'url.foo.com' part of $file and replace with random subdomain choice from list
 // $file = "https://someotherplace.foo.com/w_Path/SomeFile.ext";
$params['file'] = $file

Qirel · Accepted Answer · 2019-07-27 20:21:00Z

1

Put the values you randomly want to select into an array, use array_rand() to pick a random element (this returns the key, so you have to select the value from the array again based on the key you got), then use str_replace() to replace the value.

If the search-string ("needle", in your case url.foo.com) is not found, no replacement will happen. Beware, that this will replace all instances of that needle if it occurs more than once.

$random_values = ['differentsubdomain.foo.com', 'anotherplace.foo.com', 'someotherplace.foo.com'];
$random = $random_values[array_rand($random_values)];


$file = "https://url.foo.com/w_Path/SomeFile.ext";
$file = str_replace('url.foo.com', $random, $file);

Live demo at https://3v4l.org/um719

You can also use array_flip(), and use array_rand() on that to achieve the same result.

$random = array_rand(array_flip($random_values));

Live demo of that at https://3v4l.org/X5KA3

answered Jul 27, 2019 at 20:21

Qirel

26.6k7 gold badges54 silver badges71 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Qirel Over a year ago

Yes, just put that code in a loop that loops over all the relevant files (which is represented by elements in the array)

Qirel Over a year ago

Can't really be more specific without seeing the structure of the array.

Qirel Over a year ago

Just loop over it, pass by reference (the & in the foreach) and edit. 3v4l.org/TcP5S

Collectives™ on Stack Overflow

PHP: How to replace a segment of a string with some random text from a list

Input:

Desired output:

1 Answer 1

3 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

Input:

Desired output:

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related