preg_replace all newlines within quotes [duplicate] - php

Question

This question already has answers here:
How to replace new lines by regular expressions
(2 answers)
Closed 9 years ago.
I am trying to replace any newline characters that are with a quoted string e.g.
$help = '"Hi this is a string and I really want to replace
any newlines that are within that string" "There are multiple strings all within one string that all need
to have their newlines replaces"';
I have tried all sorts. The problem is I can't get rid of the line endings themselves. Otherwise the fgetcsv function returns a single array. It needs to be line endings / newlines within the quotes.
$str = str_replace(PHP_EOL, '', $str);
Okay here's my code. Download the csv file.
<?php
$username = 'username';
$password = 'password';
$loginURL = 'http://www.example.com/login';
$contentURL = 'http://www.example.com/feedback.csv';
// Initialize the curl
$ch = curl_init();
// Pass the curl some options
curl_setopt($ch, CURLOPT_URL, $loginURL);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, 'inp-email=' . $username . '&inp-pass=' . $password);
curl_setopt($ch, CURLOPT_COOKIEJAR, 'cookie.txt');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
// Execute the curl to login
$store = curl_exec($ch);
// Change the URL to the CSV and execute
curl_setopt($ch, CURLOPT_URL, $contentURL);
$content = curl_exec($ch);
// Time to sanitise, first I want to remove any newlines from customers comments
$content = '\"' .implode('"', explode(PHP_EOL, $content)) . '\"';
// Return the file contents
file_put_contents('feedback.csv', $content)
And then the file that grabs the CSV file and prints it out at the moment...
<?php
// Function to loop through CSV and build up array
function readCSV($csvFile){
$file_handle = fopen($csvFile, 'r');
while (!feof($file_handle) ) {
$csvlines[] = fgetcsv($file_handle, 0, "\t");
}
fclose($file_handle);
return $csvlines;
}
// Set path to CSV file
$csvFile = 'feedback.csv';
// Read the CSV file and build array using readCSV function
$csv = readCSV($csvFile);
echo '<pre>';
foreach($csv as $line){
if(count($line) != 16){
print_r($line);
}
}
echo '</pre>';
So to reiterate I am trying to go from this:
$str = '"this string has no new lines" "but this one does have new
lines to strip out"';
to:
$str = '"this string has no new lines" "but this one does have new lines to strip out"';

Answer 1

Here's one possible approach to solve the problem given in the original question (demo): one can remove all the newlines within the double quoted strings (but only those!) by...
preg_replace('#\\n(?=[^"]*"[^"]*(?:"[^"]*"[^"]*)*$)#' , ' ', $help);
The core idea is very simple: for each end of line symbol, we make sure that it's followed by (DQM = ")...
any number of non-DQM symbols, then...
exactly one DQM, then...
any number of non-DQM, then...
any number of single DQM - any number of non-DQM - single DQM - any number of non-DQM combos, then...
the end of string.
For properly formed string, this will result in collecting endlines lying in between double quotation marks, as asked.
There's a caveat to this approach, though. Obviously we won't be able to correct the line if it has an odd number of DQMs (even more, it will work incorrectly in this case). That's easy to check, just count the DQMs in the string. BTW, desired behaviour is a bit unclearly for such strings:
"should "we
replace" endline here
?
In theory, it still can be fixed a bit, by using look-behind instead of look-ahead, something like this...
preg_replace('#(?<=^(?:[^"]*"[^"]*")*[^"]*"[^"]*)\\n#' , ' ', $help);
... but in practice, one can't (still) use look-behind expressions of variable length in PHP. So you have to resort to parsing this string in this case.
If this consideration is not relevant in your case, though, the approach shown might be helpful, I suppose.

Answer 2

Try this:
$str = implode('', explode(PHP_EOL, $str));
If it's not working, try to hardcode the PHP_EOL constant:
$str = implode('', explode("\r\n", $str));
If it is still not working, try to treat your CSV file here:
foreach($csv as $line){
if(count($line) != 16){
print_r(implode('', explode("\n", $line)));
}
}