Endline after certain number of characters - php

Question

I have a text file with a lot of inserts that looks like this:
INSERT INTO yyy VALUES ('1','123123','da,sdadwa','6.7','24f,5','f5,5','dasdad,fsdfsdfsfsasada dasdasd','aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa','dasdasd','q231e','','0','','g','1','123123','dasdadwa','6.7','24f,5','f5,5','dasdad,fsdfsdfsfsasada dasdasd','','','q231e','','0','','a','1','123123','dasdadwa','655.755','24f,5','f5,5','dasdad,fsdfsdfsfsasada dasdasd','','','q231e','','','','a');
INSERT INTO yyy VALUES ('2','123123','dasdadwa','6.8','24f,6','f5,5','dasdad,fsdfsdfsfsasada dasdasd','aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa','dasdasd','q231e','','0','','g','2','123123','dasdadwa','6.8','24f,6','f5,5','dasdad,fsdfsdfsfsasada dasdasd','','','q231e','','0','','a','2','123123','dasdadwa','6.8','24f,6','f5,5','dasdad,fsdfsdfsfsasada dasdasd','','','q231e','','','','a');
INSERT INTO yyy VALUES ('3','123123','dasdadwa','6.9','24f,7','f5,5','dasdad,fsdfsdfsfsasada dasdasd','aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa','dasdasd','q231e','','0','','g','3','123123','dasdadwa','6.9','24f,7','f5,5','dasdad,fsdfsdfsfsasada dasdasd','','','q231e','','0','','a','3','123123','dasdadwa','6.9','24f,7','f5,5','dasdad,fsdfsdfsfsasada dasdasd','','','q231e','','','','a');
INSERT INTO yyy VALUES ('4','123123','dasdadwa','6.10','24f,8','f5,5','dasdad,fsdfsdfsfsasada dasdasd','aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa','dasdasd','q231e','','0','','g','4','123123','dasdadwa','6.10','24f,8','f5,5','dasdad,fsdfsdfsfsasada dasdasd','aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa','','q231e','','0','','a','4','123123','dasdadwa','6.10','24f,8','f5,5','dasdad,fsdfsdfsfsasada dasdasd','aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa','','q231e','','','','a');
INSERT INTO yyy VALUES ('5','123123','dasdadwa','6.11','24f,9','f5,5','dasdad,fsdfsdfsfsasada dasdasd','aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa','dasdasd','q231e','','0','','g','5','123123','dasdadwa','6.11','24f,9','f5,5','dasdad,fsdfsdfsfsasada dasdasd','aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa','','q231e','','0','','a','5','123123','dasdadwa','6.11','24f,9','f5,5','dasdad,fsdfsdfsfsasada dasdasd','aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa','','q231e','','','','a');
I must modify this text file so that each line can have a maximum of 50 characters. The problem is that I cannot simply put an endline after 50 characters because that would break the elements in those inserts, so I need to put the endline before the last comma.
For the first row it needs to be something like this:
INSERT INTO yyy VALUES ('1','123123','da,sdadwa',
'6.7','24f,5','f5,5',
'dasdad,fsdfsdfsfsasada dasdasd',
'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa',
'dasdasd','q231e','','0','','g','1','123123',
'dasdadwa','6.7','24f,5','f5,5',
'dasdad,fsdfsdfsfsasada dasdasd','','','q231e','',
'0','','a','1','123123','dasdadwa','655.755',
'24f,5','f5,5','dasdad,fsdfsdfsfsasada dasdasd',
'','','q231e','','','','a');
As you can see there can be commas even inside the elements('da,sdadwa') which makes this a tad more difficult. I tried putting everything into arrays but I ran into some problems and couldn't get it to work.
What i tried:
if(is_array($testFileContents))
{
foreach($testFileContents as $line)
{
$j=0;
for($i=0;$i<=strlen($line);$i++)
{
//echo $line[$i];
$ct=1;
if($j==50)
{
if($line[$j]==",")
{
//$line[$j]=$line[$j].PHP_EOL;
}
else
{
$temporaryJ = $j;
while($line[$temporaryJ]!=",")
{
$temporaryJ--;
}
//$line[$temporaryJ] = $line[$temporaryJ].PHP_EOL;
//$j=$i-$ct*50;
$j=0;
$ct=$ct+1;
echo $ct." ";
}
}
else
{
$j++;
}
}
}
}
I know there has to be a much more simple way of going around this without using arrays but I cannot figure it out.

Answer 1

You can use preg_split() to split the lines. I found a pattern another user posted in this answer for matching values for an INSERT statement:
"~'(?:\\\\'|[^'])*'(*SKIP)(*F)|,~". This utilizes Special Backtracking Control Verbs.
You can play with the PHP code in this PhpFiddle.
foreach($lines as $line) {
$matches = preg_split("~'(?:\\\\'|[^'])*'(*SKIP)(*F)|,~",$line);
$currentIndex = 0;
$currentLine = '';
$outputLines = array();
$delimeter = ',';
while($currentIndex < count($matches)) {
if ($currentIndex == count($matches)-1 ) {
$delimeter = '';
}
$tempLine = $currentLine . $matches[$currentIndex] . $delimeter;
if (strlen($tempLine) <= 50) {
$currentLine .= $matches[$currentIndex] . $delimeter;
}
else {//push current line into array and start a new line
$outputLines[] = $currentLine;
$currentLine = $matches[$currentIndex] . $delimeter;
}
if ($currentIndex == count($matches)-1 ) {
$outputLines[] = $currentLine;
}
$currentIndex++;
}
//can use implode("\n",$outputLines) to write out to file
//or whatever your needs are
}