explode csv file on delimiter (;) and delimiter(,)? - php

Question

when I explode csv file on delimiter (;)
the explode successfully in some excel program and failed in others
also when I explode csv file on delimiter (,)
the explode successfully in some excel program and failed in others
How can I do explode in all versions of excel?
How can I know the perfect delimiter to explode?
yes there is code..
if (!function_exists('create_csv')) {
function create_csv($query, &$filename = false, $old_csv = false) {
if(!$filename) $filename = "data_export_".date("Y-m-d").".csv";
$ci = &get_instance();
$ci->load->helper('download');
$ci->load->dbutil();
$delimiter = ";";
$newline = "\r\n";
$csv = "Data:".date("Y-m-d").$newline;
if($old_csv)
$csv .= $old_csv;
else
$csv .= $ci->dbutil->csv_from_result($query, $delimiter, $newline);
$columns = explode($newline, $csv);
$titles = explode($delimiter, $columns[1]);
$new_titles = array();
foreach ($titles as $item) {
array_push($new_titles, lang(trim($item,'"')));
}
$columns[1] = implode($delimiter, $new_titles);
$csv = implode($newline, $columns);
return $csv;
}
}
sometimes I put $delimiter = ";";
and sometims $delimiter = ",";
thanks..

Answer 1

You can use helper function to detect best delimiter like:
public function find_delimiter($csv)
{
$delimiters = array(',', '.', ';');
$bestDelimiter = false;
$count = 0;
foreach ($delimiters as $delimiter)
if (substr_count($csv, $delimiter) > $count) {
$count = substr_count($csv, $delimiter);
$bestDelimiter = $delimiter;
}
return $bestDelimiter;
}

Answer 2

If you have an idea of the expected data (number of columns) then this might work as a good guess, and could be a good alternative to comparing which occurs the most (depending on what kind of data you're expecting).
It would work even better if you have a header record, I'd imagine. (You could put in a check for specific header values)
Sorry for not fitting it into your code, but I am not really sure what those calls you are making do, but you should be able to fit it around.
$expected_num_of_columns = 10;
$delimiter = "";
foreach (array(",", ";") as $test_delimiter) {
$fid = fopen ($filename, "r");
$csv_row = fgetcsv($fid, 0, $test_delimiter);
if (count($csv_row) == $expected_num_of_columns) {
$delimiter = $test_delimiter;
break;
}
fclose($fid);
}
if (empty($delimiter)) {
die ("Input file did not contain the correct number of fields (" . $expected_num_of_columns . ")");
}
Don't use this if, for example, all or most of the fields contain non-integer numbers (e.g. a list of monetary amounts) and has no header record, because files separated by ; are most likely to use , as the decimal point and there could be the same number of commas and semi-colons.

Answer 3

The short answer is, you probably can't unless you can apply some heuristic to determine the file format. If you don't know and can't detect the format of the file you're parsing, then parsing it is going to be difficult.
However, once you have determined (or, required a particular one) the delimiter format. You will probably find that php's built-in fgetcsv will be easier and more accurate than a manual explode based strategy.

Answer 4

There is no way to be 100% sure you are targeting the real delimiter. All you can do is guessing.
You should start by finding the right delimiter, then explode the CSV on this delimiter.
To find the delimiter, basically, you want a function that counts the number of , and the number of ; and that returns the greater.
Something like :
$array = explode(find_delimiter($csv), $csv);
Hope it helps ;)
Edit : Your find_delimiter function could be something like :
function find_delimiter($csv)
{
$arrDelimiters = array(',', '.', ';');
$arrResults = array();
foreach ($arrDelimiters as $delimiter)
{
$arrResults[$delimiter] = count(explode($delimiter, $csv));
}
$arrResults = rsort($arrResults);
return (array_keys($arrResults)[0]);
}

Answer 5

Well, it looks like you exactly know that your delimiter will be "," or ";". This is a good place to start. Thus, you may try to replace all commas (,) to semicolons (;), and then explode by the semicolon only. However, in this approach you would definitely have a problem in some cases, because some lines of your CSV files could be like this:
"name,value",other name,other value,last name;last value
In this way delimiter of your CSV file will be comma if there will be four columns in your CSV file. However, by changing commas to semicolons you would get five columns which would be incorrect. So, changing some delimiter to another is not a good way.
But still, if your CSV file is correctly formatted, then you may find correct delimiter in any of the lines. So, you may try to create some function like find_delimiter($csvLine) as proposed by #johnkork, but the problem with this is that the function itself can't know which delimiter to search for. However, you exactly know all the possible delimiters, so you may try to create another, quite similar, function like delimiter_exists($csvLine, $delimiter) which returns true or false.
But even the function delimiter_exists($csvLine, $delimiter) is not enough. Why? Because for the instance of CSV line provided above you would get that both "," and ";" are delimiters that exists. For comma it would CSV file with four columns, and for semicolon it would be two columns.
Thus, there is no universal way which would get you exactly what you want. However, there may be another way you can check for - the first line of CSV file which is the header assuming your CSV files have a header. Mostly, headers in CSV file have (not necessarily) no other symbols, except for the alphanumeric names of the columns, which are delimited by the specific delimiter. So, you may try to create function like delimiter_exists($csvHeader, $delimiter) whose implementation could be like this:
function delimiter_exists($csvHeader, $delimiter) {
return (bool)preg_match("/$delimiter/", $csvHeader);
}
For you specific case you may use it like this:
$csvHeader = "abc;def";
$delimiter = delimiter_exists($csvHeader, ',') ? ',' : ';';
Hope this helps!