Format line as CSV and write to file pointer

Description

fputcsv(
    resource $stream,
    array $fields,
    string $separator = ",",
    string $enclosure = "\"",
    string $escape = "\\",
    string $eol = "\n"
): int|false

fputcsv() formats a line (passed as a fields array) as CSV and writes it (terminated by a eol) to the specified stream.

Parameters

stream: The file pointer must be valid, and must point to a file successfully opened by fopen() or fsockopen() (and not yet closed by fclose()).
fields: An array of strings.
separator: The separator parameter sets the field separator. It must be a single byte character.
enclosure: The enclosure parameter sets the field enclosure character. It must be a single byte character.
escape: The escape parameter sets the escape character. It must be a single byte character or the empty string. The empty string ("") disables the proprietary escape mechanism.

Warning
In the input stream, the enclosure character can always be escaped by doubling it inside a quoted string, resulting in a single enclosure character in the parsed result. The escape character works differently: If a sequence of escape and enclosure characters appear in the input, both characters will be present in the parsed result. So for the default parameters, a CVS line like "a""b","c\"d" will have the fields parsed as a"b and c\"d, respectively.

Warning
As of PHP 8.4.0, depending on the default value of escape is deprecated. It needs to be provided explicitly either positionally or by the use of named arguments.
eol: The optional eol parameter sets a custom End of Line sequence.

Warning

When escape is set to anything other than an empty string ("") it can result in CSV that is not compliant with » RFC 4180 or unable to survive a roundtrip through the PHP CSV functions. The default for escape is "\\" so it is recommended to set it to the empty string explicitly. The default value will change in a future version of PHP, no earlier than PHP 9.0.

Note:
If an enclosure character is contained in a field, it will be escaped by doubling it, unless it is immediately preceded by an escape.

Return Values

Returns the length of the written string or false on failure.

Errors/Exceptions

Throws a ValueError if separator or enclosure is not one byte long.

Throws a ValueError if escape is not one byte long or the empty string.

Changelog

Version	Description
8.4.0	Relying on the default value of `escape` is now deprecated.
8.1.0	The optional `eol` parameter has been added.
7.4.0	The `escape` parameter now also accepts an empty string to disable the proprietary escape mechanism.

Examples

Example #1 fputcsv() example

<?php

$list = [
    ['aaa', 'bbb', 'ccc', 'dddd'],
    ['123', '456', '789'],
    ['"aaa"', '"bbb"']
];

$fp = fopen('file.csv', 'w');

foreach ($list as $fields) {
    fputcsv($fp, $fields, ',', '"', '');
}

fclose($fp);
?>

The above example will write the following to file.csv:

aaa,bbb,ccc,dddd
123,456,789
"""aaa""","""bbb"""

fputcsv