PHP File Handling

📁 PHP File Handling Tutorial

PHP provides functions to create, open, read, write, append, and delete files. File handling is useful for storing data, logs, user input, or configuration without using a database.

1️⃣ Opening a File (`fopen`)

Modes in `fopen()`

Mode	Description
`r`	Read only (file must exist)
`w`	Write only (creates file or truncates existing file)
`a`	Append only (creates file if not exists)
`r+`	Read and write (file must exist)
`w+`	Read and write (creates or truncates file)
`a+`	Read and append (creates file if not exists)

2️⃣ Writing to a File (`fwrite`)

✅ w mode overwrites existing content.

3️⃣ Appending to a File (`a` Mode)

4️⃣ Reading a File (`fread`)

5️⃣ Reading a File Line by Line (`fgets`)

6️⃣ Reading a File into an Array (`file()`)

7️⃣ Deleting a File (`unlink`)

8️⃣ Checking if a File Exists (`file_exists`)

9️⃣ File Upload Example

HTML Form:

PHP Script (upload.php):

<?php
if (isset($_FILES['myfile'])) {
$filename = $_FILES['myfile']['name'];
$tempname = $_FILES['myfile']['tmp_name'];
$folder = "uploads/" . $filename;

if (move_uploaded_file($tempname, $folder)) {
echo "File uploaded successfully.";
} else {
echo "Failed to upload file.";
}
}
?>

<?php

if (isset($_FILES['myfile'])) {

$filename = $_FILES['myfile']['name'];

$tempname = $_FILES['myfile']['tmp_name'];

$folder = "uploads/" . $filename;

if (move_uploaded_file($tempname, $folder)) {

echo "File uploaded successfully.";

} else {

echo "Failed to upload file.";

}

🏁 Summary

Use fopen(), fread(), fwrite(), fclose() for basic file operations.
a mode appends data; w mode overwrites.
file() reads file into array; fgets() reads line by line.
Always check with file_exists() before reading or deleting.
unlink() deletes a file.
File upload requires enctype="multipart/form-data" in the form.

PHP File Handling