Basic File Functions in PHP
file_exists( ) file_size( ) basename( ) fopen( ) fclose( )
File_Exists( )
- Use the file_exists( ) function to determine whether or not a file exists.
- Returns true if it does exist; false if not
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Example
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<?php
$filename = "practice6.txt";
if (file_exists($filename))
{
echo "The file $filename exists";
}
else
{
echo "$filename does not exist";
}
?>
Filesize( )
- Use the filesize( ) function to determine the size of a file.
- Returns in bytes; false if error
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Example
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<?php
$filename = "practice6.txt";
echo $filename .':'.filesize($filename) . 'bytes';
?>
basename( )
- separates a file from its directory path
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Example
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$filename = basename("/home/Emily/documents/practice6.txt");
Opening a File: fopen( )
- To work with a file in your PHP script, you usually need to open it first.
- When you open a file, a file handle is created.
- A file handle points to the location of the file you want to access.
- The handle is removed when you close the file.
- The first argument = file name; Second argument = how you want to use it (r, r+, w, etc)
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Example
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<?php
$handle=fopen("practice6.txt", "w+") or exit ("Unable to open file!");
?>
Closing a File: fclose( )
- Once you're finished working with a file, you need to close it.
- PHP should automatically do this, but it's best to do it manually as well.
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Example
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fclose($handle);