Add string after some predefined string

Question

I have one file, eg: hello.txt with the following content in it

Hi Nice

INSERT TEXT MARKER

I want to create a script that enters "Hello World" after ####INSERT TEXT MARKER####.

I have used below code to do it.

<?php
function insert_into_file($file_path, $insert_marker, $text, $after = true) {
    $contents = file_get_contents($file_path);
    $new_contents = preg_replace($insert_marker, ($after) ? '$0' . $text : $text . '$0', $contents);
    return file_put_contents($file_path, $new_contents);
}

$file_path = "hello.txt";
$insert_marker = "####INSERT TEXT MARKER####";
$text = "Hello World";

$num_bytes = insert_into_file($file_path,$insert_marker,$text,true);

if ($num_bytes === false) {
    echo "Could not insert into file $file_path.";
} else {
    echo "Insert successful!";
}
?>

But my file goes empty. Please help!

if there is no pattern matching then why not user str_replace? — Amit Garg
– Amit Garg, Commented Feb 27, 2014 at 3:54

xdazz · Accepted Answer · 2014-02-27 04:00:01Z

1

You need the delimiter.

$new_contents = preg_replace('/'.$insert_marker.'/',  ($after) ? '$0' . $text : $text . '$0', $contents);

And it's better use preg_quote():

$new_contents = preg_replace('/'.preg_quote($insert_marker, '/').'/',  ($after) ? '$0' . $text : $text . '$0', $contents);

edited Feb 27, 2014 at 4:00

answered Feb 27, 2014 at 3:52

xdazz

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Comments

Ja͢ck · Accepted Answer · 2014-02-27 04:24:29Z

0

Besides the fact that your regular expression is missing the delimiters, you don't actually need it in the first place; the following code will do the same thing:

file_put_contents($file_path, str_replace(
    $insert_marker, 
    $after ? $insert_marker . $text : $text . $insert_marker, 
    $contents
));

answered Feb 27, 2014 at 4:24

Ja͢ck

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