将电子邮件地址与给定的字符串格式分开

Question

I have the following type of data in txt format and there are hundreds of lines as below. How to only fetch emails from them.

email1@yahoo.com,US,Wolterman,http://www.example.com/profile.php?id=12
email2@yahoo.com,UK,superman,http://www.example.com/profile.php?id=21

Answer 1

If your file is in text file and, each is in one line then you could extract each line and get email....

$array = array(); // Array where emails are stored

$handle = fopen("textfile.txt", "r");  
if ($handle) {
    while (($line = fgets($handle)) !== false) {

        $array[] = explode(",",$line)[0]; // stores email in the array

    }
} else {
    // error opening the file.
} 
fclose($handle);

print_r($array);

Answer 2

try explode()

$str = 'email1@yahoo.com,US,Wolterman,http://www.example.com/profile.php?id=12';
$res = explode(',', $str);
echo $res[0]; //email1@yahoo.com

Answer 3

Just use the below regex

/.*?@.*?(?=,)/g

DEMO

Or another option would be to split the text on \\n and then iterating on each line, split on , and capture the first element. This however is a bit over kill, when you can match it wasily with the above regex.

Answer 4

Here is one way you could do this if the addresses are always first.

$text = <<<DATA
email1@yahoo.com,US,Wolterman,http://www.example.com/profile.php?id=12
email2@yahoo.com,UK,superman,http://www.example.com/profile.php?id=21
email3@yahoo.com,US,Wolterman,http://www.example.com/profile.php?id=12
email4@yahoo.com,UK,superman,http://www.example.com/profile.php?id=21
email5@yahoo.com,US,Wolterman,http://www.example.com/profile.php?id=12
email6@yahoo.com,UK,superman,http://www.example.com/profile.php?id=21
DATA;

preg_match_all('~^[^,]+~m', $text, $matches);
echo implode("\n", $matches[0]);

Output

email1@yahoo.com
email2@yahoo.com
email3@yahoo.com
email4@yahoo.com
email5@yahoo.com
email6@yahoo.com

Answer 5

It can also be nice sometimes to use native implementations of things, like fgetcsv :

<?php
$emails = [];
if (($handle = fopen("emails.txt", "r")) !== FALSE) {
    while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) {
        $emails[] = array_shift($data);
    }
    fclose($handle);
}