Why does it add the text at the beginning of next line, and not the end of the right one?

Question

Needed solution:

I am working with a simple PHP script that should:

1. Add "value4:::" at the end of the first line in a file
2. Add ":::" at the end of all the next lines

I am novise in programming, and have sit here for two days trying to figure this out. Might be a little detail, or it might be totally wrong way of doing this task.

It might be wrong way to do this, or may be a regex problem? I really don't know.

I kindly ask you to help me with the solution.

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Information:

The file newstest.db looks like this:

ID:::value1:::value2:::value3:::
1:::My:::first:::line:::
2:::My:::second:::line:::
3:::Your:::third:::line:::

And using this php script I'd like to make it look like this:

ID:::value1:::value2:::value3:::value4:::
1:::My:::first:::line::::::
2:::My:::second:::line::::::
3:::Your:::third:::line::::::

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Problem:

So far I have almost got it, but I am confused to why it adds the "value4:::" to the beginning of the second line, and then add ":::" at the beginning (not end) of all of the rest of the lines.

So I get a file that looks like this:

ID:::value1:::value2:::value3:::
value4:::1:::My:::first:::line:::
:::2:::My:::second:::line:::
:::3:::Your:::third:::line:::

I thought that:

$lineshere = 'Some text here:::';    
$lines1 = $linehere.'value4:::';

would output "Some text here:::value4:::"

May be the problem is due to this way of adding line after line?

$lines = '';
$lines.= 'My test';
$lines.= ' is here';
echo $lines;

I am a novise in programming, so I might have used totally wrong functions tec to make this work.

But in this case it seams to add a space or line break/ line end in the wrong place.

---

My try on this solution:

<?php
// specify the file
$file_source="newstest.db";

// get the content of the file
$newscontent = file($file_source, true);

//set a start value (clear memory)
$lines ='';

// get each line and treat it line by line. 

foreach ($newscontent as $line_num => $linehere) {  

    // add "value4:::" at the end of FIRST line only, and put it in memory $lines 
    if($line_num==0) {
        $lines.= $linehere.'value4:::';

        // Just to see what the line looks like
        //echo 'First line: '.$lines.'<br /><br />';
    }

    // then add ":::" to the other lines and add them to memory $lines
    if($line_num>0) {
        $lines1 = $linehere.':::';
        $lines.= $lines1;

        //just look at the line
        //echo 'Line #'.$line_num.': '.$lines1.'<br /><br />';
    }
}

//Write new content to $file_source
$f = fopen($file_source, 'w');
fwrite($f,$lines);
fclose($f);

echo "// to show the results ar array<br /><br />";

$newscontentlook = file($file_source, true);
print_r(array_values($newscontentlook));
?>

Answer 1

the function file() gives you the file in an array with each line being an element of the array. Each ending of the line (EOL) is included in the elements. So appending text to that line will be after the EOL, and thus effectively on the beginning of the next line.

You can either choose to not use file() and explode the text yourself on the EOL, so the EOL is no longer part of the array element. Then edit the elements, and implode the array again.

Or fopen() the file, and fread() through it yourself. The latter option is preferred, as it won't load the entire file into memory at once.

Answer 2

This is actually very easy to achieve with file_get_contents and preg_replace, i.e:

$content = file_get_contents("newstest.db");
$content = preg_replace('/(^ID:.*\S)/im', '$1value4:::', $content);
$content = preg_replace('/(^\d+.*\S)/im', '$1:::', $content);
file_put_contents("newstest.db", $content);

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Output:

ID:::value1:::value2:::value3:::value4:::
1:::My:::first:::line::::::
2:::My:::second:::line::::::
3:::Your:::third:::line::::::

---

Ideone Demo

Answer 3

I think the problem is in your loop through the lines read by file() function:

foreach ($newscontent as $line_num => $linehere) {
  ...

$linehere contains a newline at the end, so you should simply chop it before using it:

foreach ($newscontent as $line_num => $linehere) {
  $linehere = chop($linehere);
  ...

If you don't chop the line contents, when you concatenate a string to it, you'll get:

LINE_CONTENTS\nSTRING_ADDED

which, when printed, will be:

LINE_CONTENTS
STRING_ADDED

Hope this helps...