PHP fgetcsv Function

last modified April 3, 2025

The PHP fgetcsv function reads a line from a file pointer and parses it as CSV data. It’s essential for working with comma-separated values files.

Basic Definition

The fgetcsv function parses a line from an open file as CSV format. It returns an array containing the fields read or false on failure.

Syntax: fgetcsv(resource $stream, int $length = 0, string $separator = “,”, string $enclosure = ‘"’, string $escape = “\”): array|false. The function handles various CSV formats with customizable delimiters.

Basic fgetcsv Example

This shows the simplest usage of fgetcsv to read a CSV file.

basic_fgetcsv.php

<?php

declare(strict_types=1);

$file = fopen(‘data.csv’, ‘r’);

if ($file !== false) { while (($row = fgetcsv($file)) !== false) { print_r($row); } fclose($file); }

This reads and parses each line of data.csv. Each row becomes a numerically indexed array. The function automatically handles quoted fields and commas.

Custom Delimiter Example

fgetcsv can work with different field separators, not just commas.

custom_delimiter.php

<?php

declare(strict_types=1);

$file = fopen(‘pipe_delimited.txt’, ‘r’);

if ($file !== false) { while (($row = fgetcsv($file, 0, ‘|’)) !== false) { print_r($row); } fclose($file); }

Here we parse a pipe-delimited file by specifying ‘|’ as the separator. The second parameter (0) means no length limit. Other common delimiters include tabs.

Handling Headers

This example demonstrates reading a CSV with headers and processing data rows.

csv_with_headers.php

<?php

declare(strict_types=1);

$file = fopen(‘users.csv’, ‘r’);

if ($file !== false) { $headers = fgetcsv($file);

while (($data = fgetcsv($file)) !== false) {
    $row = array_combine($headers, $data);
    print_r($row);
}
fclose($file);

}

We first read the header row, then combine it with each data row using array_combine. This creates associative arrays with header names as keys.

Custom Enclosure Character

This shows how to handle CSV files with different enclosure characters.

custom_enclosure.php

<?php

declare(strict_types=1);

$file = fopen(‘quoted_data.csv’, ‘r’);

if ($file !== false) { while (($row = fgetcsv($file, 0, ‘,’, “’”)) !== false) { print_r($row); } fclose($file); }

Here we specify a single quote as the enclosure character instead of the default double quote. This is useful for files where fields are enclosed in single quotes.

Processing Large Files

This example demonstrates memory-efficient processing of large CSV files.

large_file_processing.php

<?php

declare(strict_types=1);

function processLargeCsv(string $filename): void { $file = fopen($filename, ‘r’);

if ($file === false) {
    throw new RuntimeException("Failed to open file: $filename");
}

try {
    while (($row = fgetcsv($file)) !== false) {
        // Process each row without loading entire file
        processRow($row);
    }
} finally {
    fclose($file);
}

}

function processRow(array $row): void { // Implementation of row processing echo implode(’, ‘, $row) . PHP_EOL; }

This approach reads and processes one row at a time, making it memory-efficient for large files. The try-finally block ensures the file handle is always closed.

Edge Cases

fgetcsv has specific behaviors with various edge cases.

edge_cases.php

<?php

declare(strict_types=1);

$file = fopen(’edge_cases.csv’, ‘r’);

if ($file !== false) { // Empty line $empty = fgetcsv($file);

// Line with only delimiters
$delims = fgetcsv($file);

// Quoted fields with embedded delimiters
$quoted = fgetcsv($file);

print_r($empty);   // array(1) { [0]=> NULL }
print_r($delims);  // array with empty strings
print_r($quoted);  // properly parsed fields

fclose($file);

}

Empty lines return an array with a single NULL element. Lines with only delimiters return empty strings. Embedded delimiters in quoted fields are handled correctly.

Best Practices

• Error Handling: Always check if file opening succeeded.

• Resource Cleanup: Use try-finally or close files promptly.

• Memory Efficiency: Process line by line for large files.

• Validation: Validate CSV structure and data types.

• Encoding: Handle character encoding properly.

Source

PHP fgetcsv Documentation

This tutorial covered the PHP fgetcsv function with practical examples showing its usage in different CSV processing scenarios.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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