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PHP unlink() Function

Quick summary: The PHP unlink() function deletes a file.

PHP unlink() Syntax 

unlink(string $filename, ?resource $context = null): bool
PHP

PHP unlink() Basic examples 

file_put_contents('temp.txt', 'data');
var_dump(unlink('temp.txt'));
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Output:
bool(true)

Deletes an existing file.

PHP unlink() Real-world usage 

if (file_exists('cache.json')) {
    unlink('cache.json');
    echo 'Cache cleared';
}
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Output:
Cache cleared

Removes cached files.

PHP unlink() Edge cases 

var_dump(unlink('missing.txt'));
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Output:
bool(false)

Returns false if the file does not exist.

PHP unlink() Common mistakes

Deleting files without checks

unlink fails if the file does not exist.

Incorrect
unlink('file.txt');
Correct
if (is_file('file.txt')) unlink('file.txt');

Check file existence before deleting.

PHP unlink() Frequently Asked Questions

What does unlink() do?

Deletes a file from the filesystem.

Does unlink() delete directories?

No, use rmdir() for directories.

Return value?

True on success, false on failure.

Use case?

Removing temporary or uploaded files.

Common mistake?

Trying to delete directories.

Can fail silently?

Yes, check return value.

Permissions required?

Yes.

Safe with user input?

Validate paths strictly.

Performance?

Fast.

Can delete open file?

Depends on OS.

Alternative?

Filesystem APIs.

Best practice?

Check file_exists() first.

PHP unlink() Related PHP Functions