How to loop line by line.

[Nyla]

I'm so sorry to ask such a "newbee question," but believe me I have been on Google for the better part of the week trying to find an answer.

 

I'll start with the brief question.

Then I'll give an example to show what I mean.

Then, I'll give the BESTEST "pseudo-code" I could come up with (to PROVE that I've really given it my best).

 

Question:

How do I make PHP loop through a big file, make the changes line by line, and to save the resultant file.

 

Example: I have a 100mb text file ("animals.txt") with 500,000 lines. If any lines have the word "cat" in it, I want to add "Be careful with cats!" to the end of the line:

 

From this:

A fish and his tank.

A cat and his toy.

A bird and her cage.

A frog and his lilly.

A cat and her friend.

 

To this:

A fish and his tank.

A cat and his toy. Be careful with cats!

A bird and her cage.

A frog and his lilly.

A cat and her friend. Be careful with cats!

 

The best "pseudo-code" I can come up with is:

 

<?php

$data = file_get_contents("animals.txt");

$lines = explode(PHP_EOL,$data);

foreach($lines as $line){

if(stristr($line,'cat')) { $line = $line.' Be careful with cats!'; }

$result .= $line;

fwrite($result,'MyNewFixedFile.txt')

?>

 

I know this looks like a long drawn out question, but I worked really hard on trying to figure it out myself, and I worked really hard on making it concise and easy to understand. Would someone please tell me what to do to make this work? Hopefully, my "pseudo-code" is close to being correct. But if it's totally horrible, I don't have any ego in this one, so you can tell me it is horrible and I won't take it personally.

 

THANK YOU!!!

 

 

 

 

 

[requinix]

If you used file_put_contents instead of fwrite(), you'd have yourself a winner.

 

But I'd do it a bit differently:

$lines = file("animals.txt");
foreach ($lines as $n => $line) {
    if (stripos($line, "cat") !== false) {
        $line = rtrim($line) . " Be careful with cats!" . PHP_EOL;
    }
}
file_put_contents("animals.txt", $lines);

If the file was much larger, though, (and 100MB may be too large already,) you'd need to use a different tactic: you'd run out of memory to store the entire file in PHP's memory.

[Nyla]

Uh-oh, for some reason, your code doesn't work (none of the lines get changed).

 

I thought it was because you have "$lines" plural, (so I made it $line), but it still doesn't work. 

 

I'm staring at it and staring at it, but my mind is as blank as a cloud right now, I can't figure it out?

Edited November 20, 2014 by Nyla

[Barand]

Change

$line = rtrim($line) . " Be careful with cats!" . PHP_EOL;

to

$lines[$n] = rtrim($line) . " Be careful with cats!" . PHP_EOL;

[requinix]

Change

$line = rtrim($line) . " Be careful with cats!" . PHP_EOL;

to

$lines[$n] = rtrim($line) . " Be careful with cats!" . PHP_EOL;

I blame my sick boss for making me sick too and thus not quite in my right mind. But at least I did get the $n=>.

[Barand]

I know the feeling. I can always fall back on "senility" when the need arises.

[Nyla]

Thank you, y'all! The code actually works:

 

<?php

$lines = file("animals.txt");

foreach ($lines as $n => $line) {

    if (stripos($line, "cat") !== false) {

        

        $lines[$n] = rtrim($line) . " Be careful with cats!" . PHP_EOL;

    }

}

file_put_contents("animals.txt", $lines);

 

This is the FIRST forum I have ever asked a question to where it just gets answered, I cannot believe it! Thank you all so much!

 

Usually, well, NOT "usually".... ALWAYS, this is what happens:

 

Me: How do I make PHP loop line through line?

1st response: "Why do you need to loop line by line?"

2nd response: "Google FOPEN"

3rd response: "This can be done in Perl"

4th response: "It's just simple loops"

Me: I cannot figure out how to loop line by line.

5th response: "What kind of project are you working on?"

Me: It's complicated, I just can't figure out how to loop.

6th response: "This isn't a 'free coding' help center, you need not be rude.

Me: I wasn't rude.

7th response [moderator]: Saying you're not rude, is rude. You are now banned

 

So, I think I've finally found a decent forum!

 

Thank you, everybody!