Read CSV records incrementally and process bounded batches, avoiding memory growth proportional to the input file. The examples below demonstrate the main workflow, an edge case and one practical integration pattern.
What Does This Workflow Do?
Use the first example to see the core idea. The additional examples demonstrate validation and a separate integration scenario. Use fgetcsv()/fputcsv() with an explicit escape parameter and consider formula injection when exporting spreadsheets.
Syntax:
The complete workflow is demonstrated below; individual calls are explained in context.
Requirements and Data Flow
There is no single function signature for this workflow. The required variables depend on the request, server configuration and libraries used in the examples.
Example 1: Basic Usage
Read CSV records incrementally and process bounded batches, avoiding memory growth proportional to the input file.
<?php
$stream = fopen(__DIR__ . "/data.csv", "rb");
if ($stream === false) { throw new RuntimeException("Missing CSV file"); }
$batch = [];
while (($fields = fgetcsv($stream, 0, ",", '"', "")) !== false) { $batch[] = $fields; if (count($batch) >= 500) { processBatch($batch); $batch = []; } }
if ($batch !== []) { processBatch($batch); }
fclose($stream);
This example demonstrates the central operation. The final output depends on the supplied input and, where relevant, the runtime or connected service.
Example 2: Handling a Different Case
<?php
$record = ["value, with comma", 'quote " inside', "ordinary"];
$handle = fopen("php://temp", "w+");
fputcsv($handle, $record, ",", '"', "");
rewind($handle);
print_r(fgetcsv($handle, 0, ",", '"', ""));
fclose($handle);
The second example focuses on a different input or failure condition, so the behavior can be distinguished from the basic case.
Practical Example
<?php
$records = [["sku", "price"], ["A12", "19.50"]];
$handle = fopen("php://temp", "w+");
foreach ($records as $record) { fputcsv($handle, $record, ",", '"', ""); }
rewind($handle);
echo stream_get_contents($handle);
fclose($handle);
The practical example demonstrates how the same subject fits into a larger application. Use your own file paths, endpoints and validated inputs rather than copying sample settings directly.
Important Behavior and Edge Cases
- Use fgetcsv()/fputcsv() with an explicit escape parameter and consider formula injection when exporting spreadsheets.
- Keep the example scoped to its stated purpose. A sample does not replace application authentication, authorization, production configuration or deployment review.
- Use the documented return type and handle false, null and exceptions according to the specific call.
Comparison With Related Functions
| Approach | Difference |
|---|---|
| Processing Large CSV Files in Chunks | Read CSV records incrementally and process bounded batches, avoiding memory growth proportional to the input file. |
| Streaming reads | Processes bytes in chunks instead of loading an entire file into memory. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
| Splitting CSV on commas manually | Use a CSV parser that handles quoted delimiters and line breaks. |
| Using default CSV backslash escaping without considering round trips | Pass explicit CSV escape settings; use empty escape when appropriate. |
| Exporting untrusted formulas directly to spreadsheets | Mitigate spreadsheet formula injection for exported text fields. |
Key Takeaways
- Use fgetcsv()/fputcsv() with an explicit escape parameter and consider formula injection when exporting spreadsheets.
- Keep the example scoped to its stated purpose. A sample does not replace application authentication, authorization, production configuration or deployment review.
- Use the documented return type and handle false, null and exceptions according to the specific call.
Read CSV records incrementally and process bounded batches, avoiding memory growth proportional to the input file. Use this approach when its capabilities and constraints match the application. Handle invalid data, failure conditions and resource cleanup explicitly.