How to remove CSV file lines using PHP?

Question

I need to remove the first two lines of a CSV file, it has some function for this in PHP?

Answer 1

I like to use the function SplFileObjectPHP. You can open the file and point to the line from which you want to read the file through the function seek.

Example relatorio.csv:

a1,b1,c1
a2,b2,c2
a3,b3,c3
a4,b4,c4
a5,b5,c5

The code would look like this:

$file = new \SplFileObject('relatorio.csv', 'r');

// Coloca o ponteiro na segunda linha do arquivo
$file->seek(1);

// continue o laço até que seja o fim da linha
while ($file->eof() === false) {
    // obtém o dado de uma linha do CSV
    var_dump($file->fgetcsv());
}

The result would be this:

array(3) {
  [0]=>
  string(2) "a3"
  [1]=>
  string(2) "b3"
  [2]=>
  string(2) "c3"
}
array(3) {
  [0]=>
  string(2) "a4"
  [1]=>
  string(2) "b4"
  [2]=>
  string(2) "c4"
}
array(3) {
  [0]=>
  string(2) "a5"
  [1]=>
  string(2) "b5"
  [2]=>
  string(2) "c5"
}

Remark: THE fseek puts the reading of the file from the informed line. PHP counts the file lines from the 0.

You can also use the function array_slice combined with file to get all lines from the file in the array. The file opens each line in a array, and the array_slice "cuts" the array at the indicated value.

Behold:

 var_dump(array_slice(file('relatorio.csv'), 2));

Observing: Only use the second example if the size of the CSV is small, because depending on the amount of line, it may overload the memory, because file reads each line for one array.

The first solution reads line by line, saving processing/memory.

Answer 2

It is possible to do this in PHP although it is not a single function as you asked:

// Leia o arquivo
$arquivo = fopen('seu_arquivo.csv', 'r');

// Pega todas as linhas do arquivo
while (($linha = fgetcsv($arquivo)) !== FALSE) {
  // Armazena as linhas em um array de dados
  $dados[] = $linha;
}
fclose($arquivo);

// Remove o primeiro elemento do array (ou seja, a primeira linha do arquivo que foi salva)
array_shift($dados);

// Faz novamente para removera segunda
array_shift($dados);

// Abre arquivo para escrita
$arquivo = fopen('seu_arquivo.csv', 'w');

// Escreve no arquivo as linhas salvas no array
foreach ($dados as $dado) {
    fputcsv($arquivo, $dado);
}
fclose($arquivo);

If you just want the data and don’t want to over-write the file, just ignore the last 7 lines of code and use the array $dados.