如何从php中的数组回显？

Question

I have a text file, with digits in it like the following:

12345678901234567890
123456789012345678901
123456789012345678902
1234567890123456789012
1234567890123456789023
12345678901234567890123
12345678901234567890234

I wrote a script to read this file line by line. I want to count the characters in the line, not just the bytes, and and only select the lines that contain 21 or 22 characters.

Using the script below works. Don't ask me why it read 21 characters when I said 23. I think it's something to do with file encoding since strlen only got me the bytes.

After selecting the lines that are of length 21 or 22 characters, I need to split the line. If it's 21, it should become two strings (a 15 character string and a 6 character string), and if it is 22 characters should be split into a 16 character string and a 6 character string.

I tried making it in an array, but the array shows something like this:

Array ( [0] => 123456789012345 [1] => 678901 ) Array ( [0] => 123456789012345 [1] => 678903 )

I want it to show like this instead:

123456789012345=678901
123456789012345=678903

Any idea how I can echo from an array?

$filename = "file.txt";
$fp = fopen($filename, "r") or die("Couldn't open $filename");

while (!feof($fp)){
    $line = fgets($fp);
    $str = strlen($line);
    if($str == 23){
        $str1=str_split($line, 15);
        print_r($str1);
        foreach ($str1 as $value)
        {
           echo $value . "=" ;
        }
    }
    if($str == 24){
        $str1=str_split($line, 16);

        foreach ($str1 as $value)
        {
            echo $value . "=" ;
        }
    }

}

Answer 1

Just some pointers:

$filename = "file.txt";
$lines    = file($filename, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
if ($lines === FALSE) {
   die "Couldn't open $filename";
}

foreach ($lines as $line)
{
    $length = strlen($line);

    if ($length < 21 || $length > 22)  {
        continue;
    }

    $start = 15;
    if ($length === 22) {
        $start = 16;
    }

    echo substr($line, 0, $start), '=', substr($line, $start), "\n";
}

That is using file and substr . In PHP a character is one byte.

---

A different example:

$filename = "file.txt";
$lines    = file($filename, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
if ($lines === FALSE) {
   die "Couldn't open $filename";
}

foreach ($lines as $line)
{
    $start = strlen($line) - 6;

    if ($start === 15 || $start === 16)
    {
        echo substr_replace($line, '=', $start, 0), "\n";
    }

}

This example is using substr_replace and does the $start calculation directly upfront.