PHP doesn’t have either a delete keyword or a delete() function. Instead, it provides the unlink() function, which when called, deletes a file from the filesystem. It is similar to Unix/C unlink function.

If the delete operation could not be completed, PHP returns false and shows an E_WARNING message.

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

The mandatory string parameter to unlink() function is a string that refers to the file to be deleted.

Example

The following code demonstrates a simple use of the unlink() function −

<?php
   $file = "my_file.txt";

   if (unlink($file)) {
      echo "The file was deleted successfully.";
   } else {
      echo "The file could not be deleted.";
   }
?>

Deleting the Symlink to a File

The unlink() function can also delete a symlink to a file. However, deleting a symlink doesn’t delete the original file. A symlink is a shortcut to an existing file.

In Windows, open a command prompt with administrator privilege and use the mlink command with /h switch to create a symlink to a file. (/j switch is used for symlink to a folder)

mklink /h hellolink.lnk hello.txt
Hardlink created for hellolink.lnk <<===>> hello.txt

In Ubuntu Linux, to create a symbolic link to a file, you would use the following command −

ln -s /path/to/original_file /path/to/symlink

To create a symbolic link to a directory, you would use the following command −

ln -s /path/to/original_directory /path/to/symlink

In PHP, there is also a symlink() function for the purpose.

symlink(string $target, string $link): bool

Example

Create a symlink with the following code −

<?php
   $target = ''hello.txt'';
   $link = ''hellolink.lnk'';
   symlink($target, $link);

   echo readlink($link);
?>

Now delete the symlink created above −

unlink("hellolink.lnk");

If you check the current working directory, the symlink will be deleted, leaving the original file intact.

How to Rename a File in PHP

You can change the name of an existing file with the help of respective command from the console of an operating system. For example, the “mv command in Linux terminal or the “rename command” in Windows command prompt helps you to change the name of a file.

However, to rename a file programmatically, PHP’s built-in library includes a rename() function.

Here is the syntax of the rename() function −

rename(string $from, string $to, ?resource $context = null): bool

Both $from and $to strings are the names of files, existing and new respectively. The rename() function attempts to rename $from to $to, moving it between directories if necessary.

If you are renaming a file and $to already exists, then it will be overwritten. If you are renaming a directory and $to exists, then this function will emit a warning.

To change the name of “hello.txt” to “test.txt” −

<?php
   rename("hello.txt", "test.txt");
?>

You can also employ a little indirect approach for renaming a file. Make a copy of an existing file and delete the original one. This also renames “hello.txt” to “test.txt” −

copy("hello.txt", "test.txt");
unlink("hello.txt");