How to validate zero or more image names, allowing spaces, separated by commas or empty

Question

I need to validate images with regular expressions, with the following conditions:

$string may be empty
I can receive a single image with this format, for example: 2017-06-01-03-55-00-5930782c5c0b1.jpg
I can get several image names separated by commas example: 2017-06-01-03-55-00-5930782c5c0b1.jpg, 2017-06-01-03-55-00-5930782c5c0b1.jpg
Avoid other special characters other than these: A-Za-z0-9\-

I have managed to do this with my knowledge in regular expressions, but I have to validate, if the estring is empty, if there are several images separated by commas, and if there are no other characters than the string.

$pattern = '/[a-zA-Z0-9]\.(jpg|jpeg|png|gif)$/';
$string = '2017-06-01-03-55-00-5930782c5c0b1.jpg';

if( preg_match($pattern, $string) ) {
    echo "TRUE";
} else {
    echo "FALSE";
}

Thank you very much for your help, please.

check `empty()` then `explode()` on commas, then regular expression in array loop — , Jun 01 '17 at 23:23

mickmackusa · Accepted Answer · 2017-06-02T00:41:58.707

1

This will do all those things:

/^(?:[\dA-Za-z-]+\.(?:jpe?g|png|gif))?(?:, (?:[\dA-Za-z-]+\.(?:jpe?g|png|gif)))*$/

It will match the 2nd, 3rd, and 5th line of the following:

bad_image.jpg

2017-06-01-03-55-00-5930782c5c0b1.jpg
2017-06-01-03-55-00-5930782c5c0b1.jpeg, bad_image.jpg
2017-06-01-03-55-00-5930782c5c0b1.png, 2017-06-01-03-55-00-5930782c5c0b1.gif

Here is the Demo. My pattern will match zero or more valid image filenames which must be separated by comma-space

edited Jun 02 '17 at 00:41

answered Jun 01 '17 at 23:43

mickmackusa

43,625
12
83
136

Hello @mickmackusa, thank you very much for your answer, I have tested the sample code in PHP and it works with empty space, but not functional names of the images, look here: https://eval.in/809859 – Learning and sharing Jun 02 '17 at 00:11
This works perfect, thank you very much @mickmackusa. – Learning and sharing Jun 02 '17 at 00:24
This works perfectly in PHP, but I just added this to the Codeigniter Framework, and it shows me the following message: Message: preg_match(): No ending delimiter '/' found, reference documentation: https://codeigniter.com//user_guide/libraries/form_validation.html#rule-reference – Learning and sharing Jun 02 '17 at 00:33
@Learningandsharing You can just swap back in the lowercase characters then... `/^(?:[\dA-Za-z-]+\.(?:jpe?g|png|gif))?(?:, (?:[\dA-Za-z-]+\.(?:jpe?g|png|gif)))*$/` – mickmackusa Jun 02 '17 at 00:35
Your example works fine in PHP, but in Codeigniter it shows me the following message: Message: preg_match(): No ending delimiter '/' found – Learning and sharing Jun 02 '17 at 00:48
@Learningandsharing Hmm, curious. please post your code. – mickmackusa Jun 02 '17 at 00:50
@Learningandsharing How about this page: https://stackoverflow.com/questions/21439805/codeigniters-regex-match – mickmackusa Jun 02 '17 at 00:58
Perfect, I will use this method, thank you very much – Learning and sharing Jun 02 '17 at 01:52

Eddy Jones · Answer 2 · 2017-06-01T23:19:50.273

0

I think you might be looking for the following, since your regex pattern didn't account for the dashes.

/[a-z0-9-]+\.(jpg|jpeg|png|gif)/gi

A great resource for perfecting your regex can be found at Regexr.com

The /g at the end of the expression makes the pattern global, looking at the whole string passed to it rather than finding the first match and stopping.

The /i at the end of the expression means case insensitive so that you don't have to include both a-z and A-Z.

edited Jun 01 '17 at 23:19

answered Jun 01 '17 at 23:16

Eddy Jones

43
5

Hello Eddy, I need to know if the string is empty, if there is a comma, or more than one filename. – Learning and sharing Jun 01 '17 at 23:19
Ahhh... sorry, I missed that part. It's been too long since I've worked with PHP, so I can't help you out with that part. – Eddy Jones Jun 01 '17 at 23:32
Actually.. check this out. Found it here on StackOverflow. https://stackoverflow.com/questions/15007777/php-regex-how-to-get-an-array-of-matches – Eddy Jones Jun 01 '17 at 23:33
Hi Eddy Jones, @mickmackusa's response is very good, let's see her. – Learning and sharing Jun 02 '17 at 00:12

How to validate zero or more image names, allowing spaces, separated by commas or empty

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