Plucking variables from a text file in PHP - php

I've had a good search and not found anything relevant to my issue, so please dont down vote without showing me where you have a relevant example...
Trying to build template files as a text document to simplify it for others to modify later, but I can't work out how to get PHP to recognize the variables in it.
What I want to work:
//template.txt
Every time I find $foo,
I get a little $bar,
template text.
note: The line breaks are critical for position.
//handler.php
$foo = 'Beer';
$bar = 'Excited';
$file = file('template.txt');
foreach ($file as $line) {
echo $line;
}
What I want this to return:
Every time I find Beer,
I get a little Excited,
template text.
but it is escaping the variable mark ($),
and is returning:
Every time i find $foo,
I get a little $bar,
template text.
I tried to do a str replace with:
if (strpos($line, '\$foo')) {
str_replace('\$foo', $foo, $line);
}
(tried with and without the $ symbol, and many variations on this)
at best I can get it to recognise the variable name but it is not replacing.
Has anyone had any experience with this?
Really not finding much info on this online.
Any help will be greatly appreciated.

When you're using single quote it's auto escaping everything in there, so you're telling it to replace \$foo not $foo
str_replace('$foo', $foo, $line);
Also you don't really need the if statement, if it can't find it it's not going to do anything anyway.
If you're going to have more variables you could set up a pair of arrays and instead of iterating through it line by line just throw the whole string at it at once
$file = file('template.txt');
$search = array('$foo', '$bar');
$replace = array('Beer', 'Excited');
$file = str_replace($search, $replace, $file);
foreach ($file as $i) {
echo $i;
}

Related

PHP: Check URL against array of badwords, and output any found

I have a database which contains the results of logged network traffic, and I'm building a simple log viewer frontend in PHP. I need to check each URL and see if it contains any of the 'bad words' in an external 'badwords.txt' file, then echo which ones, and color the table row red (the easy bit!)
Thus far I have loaded the badwords.txt file into an array, and fetched the URL from the database. Here is the portion of my code where I am trying to get a positively identified 'bad' url. I ideally want to output which badwords were found, but have simplified everything to just try and get it to work for now.
// Load the badwords file into an array
$words = file('badwords.txt');
//$row[3] is the URL fetched from the database
$testURL = $row[3];
foreach ($words as $phrase) {
if (strrpos($testURL, $phrase)) {
echo "FOUND";
}
}
This is not working for me, and never outputs FOUND, even when the url definitely contains a bad word. I have checked that my $words array is populated correctly with all the badwords, and I have checked that the $testURL is not empty etc.
Can anyone help please? :) I'd be really grateful for any assistance - I have read through so many StackExchange posts on similar topics, but none seem to work for my case.
Thank you!
Words array contains newline symbol, so strpos never works. Remove them
$words = file('badwords.txt', FILE_IGNORE_NEW_LINES);
Since strrpos() returns numeric position of needle, and boolean false, so code should be
<?php
// Load the badwords file into an array
$words = file('words.txt', FILE_IGNORE_NEW_LINES);
//$row[3] is the URL fetched from the database
$testURL = row[3];
foreach ($words as $phrase) {
if (strrpos($testURL, $phrase)>-1) {
echo "FOUND";
}
}

PHP preg_replace inside for loop

I'm currently trying out this PHP preg_replace function and I've run into a small problem. I want to replace all the tags with a div with an ID, unique for every div, so I thought I would add it into a for loop. But in some strange way, it only do the first line and gives it an ID of 49, which is the last ID they can get. Here's my code:
$res = mysqli_query($mysqli, "SELECT * FROM song WHERE id = 1");
$row = mysqli_fetch_assoc($res);
mysqli_set_charset("utf8");
$lyric = $row['lyric'];
$lyricHTML = nl2br($lyric);
$lines_arr = preg_split('[<br />]',$lyricHTML);
$lines = count($lines_arr);
for($i = 0; $i < $lines; $i++) {
$string = preg_replace(']<br />]', '</h4><h4 id="no'.$i.'">', $lyricHTML, 1);
echo $i;
}
echo '<h4>';
echo $string;
echo '</h4>';
How it works is that I have a large amount of text in my database, and when I add it into the lyric variable, it's just plain text. But when I nl2br it, it gets after every line, which I use here. I get the number of by using the little "lines_arr" method as you can see, and then basically iterate in a for loop.
The only problem is that it only outputs on the first line and gives that an ID of 49. When I move it outside the for loop and removes the limit, it works and all lines gets an <h4> around them, but then I don't get the unique ID I need.
This is some text I pulled out from the database
Mama called about the paper turns out they wrote about me
Now my broken heart´s the only thing that's broke about me
So many people should have seen what we got going on
I only wanna put my heart and my life in songs
Writing about the pain I felt with my daddy gone
About the emptiness I felt when I sat alone
About the happiness I feel when I sing it loud
He should have heard the noise we made with the happy crowd
Did my Gran Daddy know he taught me what a poem was
How you can use a sentence or just a simple pause
What will I say when my kids ask me who my daddy was
I thought about it for a while and I'm at a loss
Knowing that I´m gonna live my whole life without him
I found out a lot of things I never knew about him
All I know is that I´ll never really be alone
Cause we gotta lot of love and a happy home
And my goal is to give every line an <h4 id="no1">TEXT</h4> for example, and the number after no, like no1 or no4 should be incremented every iteration, that's why I chose a for-loop.
Looks like you need to escape your regexp
preg_replace('/\[<br \/\]/', ...);
Really though, this is a classic XY Problem. Instead of asking us how to fix your solution, you should ask us how to solve your problem.
Show us some example text in the database and then show us how you would like it to be formatted. It's very likely there's a better way.
I would use array_walk for this. ideone demo here
$lines = preg_split("/[\r\n]+/", $row['lyric']);
array_walk($lines, function(&$line, $idx) {
$line = sprintf("<h4 id='no%d'>%s</h4>", $idx+1, $line);
});
echo implode("\n", $lines);
Output
<h4 id="no1">Mama called about the paper turns out they wrote about me</h4>
<h4 id="no2">Now my broken heart's the only thing that's broke about me</h4>
<h4 id="no3">So many people should have seen what we got going on</h4>
...
<h4 id="no16">Cause we gotta lot of love and a happy home</h4>
Explanation of solution
nl2br doesn't really help us here. It converts \n to <br /> but then we'd just end up splitting the string on the br. We might as well split using \n to start with. I'm going to use /[\r\n]+/ because it splits one or more \r, \n, and \r\n.
$lines = preg_split("/[\r\n]+/", $row['lyric']);
Now we have an array of strings, each containing one line of lyrics. But we want to wrap each string in an <h4 id="noX">...</h4> where X is the number of the line.
Ordinarily we would use array_map for this, but the array_map callback does not receive an index argument. Instead we will use array_walk which does receive the index.
One more note about this line, is the use of &$line as the callback parameter. This allows us to alter the contents of the $line and have it "saved" in our original $lyrics array. (See the Example #1 in the PHP docs to compare the difference).
array_walk($lines, function(&$line, $idx) {
Here's where the h4 comes in. I use sprintf for formatting HTML strings because I think they are more readable. And it allows you to control how the arguments are output without adding a bunch of view logic in the "template".
Here's the world's tiniest template: '<h4 id="no%d">%s</h4>'. It has two inputs, %d and %s. The first will be output as a number (our line number), and the second will be output as a string (our lyrics).
$line = sprintf('<h4 id="no%d">%s</h4>', $idx+1, $line);
Close the array_walk callback function
});
Now $lines is an array of our newly-formatted lyrics. Let's output the lyrics by separating each line with a \n.
echo implode("\n", $lines);
Done!
If your text in db is in every line why just not explode it with \n character?
Always try to find a solution without using preg set of functions, because they are heavy memory consumers:
I would go lke this:
$lyric = $row['lyric'];
$lyrics =explode("\n",$lyrics);
$lyricsHtml=null;
$i=0;
foreach($lyrics as $val){
$i++;
$lyricsHtml[] = '<h4 id="no'.$i.'">'.$val.'</h4>';
}
$lyricsHtml = implode("\n",$lyricsHtml);
An other way with preg_replace_callback:
$id = 0;
$lyric = preg_replace_callback('~(^)|$~m',
function ($m) use (&$id) {
return (isset($m[1])) ? '<h4 id="no' . ++$id . '">' : '</h4>'; },
$lyric);

PHP Writing long strings on separate lines

I wanted to write a line of code that contains a long string such as:
addError("This is a really really really really really really really long text");
however I wanted to split the text into multiple lines. How can this be possible aside from this way:
addError("This is a really really really really really really" .
"really long text");
EDIT: I need it such that it dosen't do line breaks either. (forget about that SQL thing i said earlier)
If SQL syntax highlighting is your problem, you can probably format it properly using a heredoc, and still get the IDE's syntax highlighting working:
$query = <<<EOD
select *
from foo
where bar
EOD;
do_query($query);
http://www.php.net/manual/en/language.types.string.php#language.types.string.syntax.heredoc
If you don't want line breaks, your way of doing it now seems right. With the above, you'd need to remove the line breaks afterwards, e.g. str_replace("\n", " ", $str).
Try this :-
$t = 'This is a really really really really really really';
$t .= ' really really really really really really';
$t .= ' really really really really really really';
$t .= ' long string';
addError( $t );
Assuming you are trying to break the output to rows, you can use str_split( $string, $chunk_length ).
This will split the long text into array of strings with a fixed length.
$array_of_strings = str_split($str, 100);//100 represents the length of the chunk
foreach ($array_of_strings as $line) {
echo $line . '<br>';
}
You can also use chunck_split();
Hope this helps!

How to expand variables in a string

Problem
I'd like to expand variables in a string in the same manner that variable in a double quoted string get expanded.
$string = '<p>It took $replace s</>';
$replace = 40;
expression_i_look_for;
$string should become '<p>It took 40 s</>';
I see a obvious solution like this:
$string = str_replace('"', '\"', $string);
eval('$string = "$string";');
But I really don't like it, because eval() is insecure. Is there any other way to do this ?
Context
I'm building a simple templateing engine, that's where I need this.
Example Template (view_file.php)
<h1>$title</h1>
<p>$content</p>
Template rendering (simplified code):
$params = array('title' => ...);
function render($view_file, $params)
extract($params)
ob_start();
include($view_file);
$text = ob_get_contents();
ob_end_clean();
expression_i_look_for; // this will expand the variables in the template
return $text;
}
The expansion of the variables in the template simplifies it's syntax. Without it, the above example template would be:
<h1><?php echo $title;?></h1>
<p><?php echo $content;?></p>
Do you think this approach is good ? Or should I look in another direction ?
Edit
Finally I understand that there is no simple solution due to flexible way PHP expands variables (even ${$var}->member[0] would be valid.
So there are only two options:
Adopt an existing full fledged templating system
Stick with something very basic that essentially is limited to including the view files via include.
I would rather suggest using some existing template engines, like for example Smarty, but if you really want to do it by yourself you can use the simple regular expression to match all variables constructed with for example letters and numbers and then replace them with correct variables:
<?php
$text = 'hello $world, what is the $matter? I like $world!';
preg_match_all('/\$([a-zA-Z0-9]+)/',
$text,
$out, PREG_PATTERN_ORDER);
$world = 'World';
$matter = 'matter';
foreach(array_unique($out[1]) as $variable){
$text=str_replace('$'.$variable, $$variable, $text);
}
echo $text;
?>
prints
hello World, what is the matter? I like World!
Parse
Parse the string look for $ followed by valid variable name (i.e. \[a-zA-Z_\x7f-\xff\]\[a-zA-Z0-9_\x7f-\xff\]*)
Variable²
Use variable variables syntax (i.e. $$var notation).
Are you trying to do this?
templater.php:
<?php
$first = "first";
$second = "second";
$third = "third";
include('template.php');
template.php:
<?php
echo 'The '.$first.', '.$second.', and '.$third.' variables in a string!';
When templater.php is run, produces:
"The first, second, and third variables in a string!"
Do you want something like this ?
$replace = 40;
$string = '<p>It took {$replace}s</p>';
Instead of using single quotes
$string = '<p>It took $replace s</>';
$replace = 40;
use double quotes
$replace = 40;
$string = "<p>It took $replace s</>";
However, for readability and to enable you to remove the space between $replace and the s I would use:
$replace = 40;
string = '<p>It took ' . $replace . 's</>';
The correct way is probably to parse your document as a tree, identify your parser tags ( because you are managing your own parser they don't have to follow php conventions if you don't want them to ) and then add in your values from an associative array or other data structure as the opportunity arises.
This is a more complex solution but will make it far easier when you realise that you want to be able to display lists whose length is unknown ahead of time using some kind of looping structure based on a standard display option. In the long run, you won't find many serious templating systems that aren't parsing the documents into some kind of in-memory tree where the placeholders can be inserted and then the document constructed as required. This also offers many opportunities for cacheing. Also, if you are unafraid of recursion you will be able to perform a lot of operations on it fairly simply.
However, this is not an uncommon problem to solve and as I commented on the question, there are almost guaranteed to be libraries and extensions around that provide most of the functionality you need. Unless this is a purely academic process for you, I would find some existing solutions and either use one of those or get a solid understanding of how it works so you have a starting point for adapting your own solution.
This is a snippet I pulled out from Lejlot's answer. I tested it and it works fine.
function resolve_vars_in_str( $input )
{
preg_match_all('/\$([a-zA-Z0-9]+)/', $input, $out, PREG_PATTERN_ORDER);
foreach(array_unique($out[1]) as $variable) $input=str_replace('$'.$variable, $GLOBALS["$variable"], $input);
return $input ;
}

How can this routine be better optimized?

The routine below does two scans over an input stream of hypertext. The first pass is a spin replacement on user defined phrase options. The second pass is a find replace on the tags collection in the doReplace function below.
I'm just looking for suggestions on how it might be optimized. I'm having no performance issues as is. But I want to build for scalability.
/* FIND REPLACE SPIN
--------------------------------------------------------------------*/
function doReplace($content)
{
// content is a precompiled text document formatted with html and
// special using replacement tags matching the $tags array collection below
$tags = array('[blog-name]', '[blog-url]', '[blog-email]');
$replacements = array('value1', 'value2', 'value3');
$content = str_replace($tags, $replacements, $content);
return $content;
}
function doSpin($content) {
// the content also has phrase option tags denoted by [%phrase1|phrase2_|phrase3%]
// delimiters throughout the text.
return preg_replace_callback('!\[%(.*?)%\]!', 'pick_one', $content);
}
function pick_one($matches) {
$choices = explode('|', $matches[1]);
return $choices[rand(0, count($choices)-1)];
}
$my_source_page = file_get_contents('path/to/source';}
$my_source1_spin = doSpin($my_source_page);
$my_source1_replace = doReplace($my_source1_spin);
$my_source1_final = addslashes($my_source1_replace);
//Now do something with $my_source1_final
To be honest, I don't see anything wrong with the code you've posted. The main bottleneck in the code is likely going to be the file_get_contents call.
The only thing I can see myself is that you're allocating the string to different variables (four variables beginning $my_source) which will use more memory than if you just used 1 or 2 variables.
But unless you're reading a large amount of text into memory very frequently on a busy site, then I don't think you need to worry about the code you've posted. And you said yourself, you're not having any performance issues at the moment ;)

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