PHP lists all subfolders and file instances of a specified directory_PHP tutorial

php tutorial lists all subfolders and file instances of a specified directory
function listDirFiles()
{
// Set directory
$dirs = './';

// Declare folder array and file array
$aFolders = array() ;
$aFiles = array() ;

$ocfolder = opendir( $dirs ) ;//The function returns a directory stream, otherwise it returns false and an error. You can hide error output by prepending "@" to the function name. Usage opendir(path,context)

while ( $sFile = readdir( $ocfolder ) ) // The readdir() function returns the entry in the directory handle opened by opendir() Syntax: readdir(dir_stream)
{
if ( $sFile != '.' && $sFile != '..' )
{
If ( is_dir( $dirs . $sFile ) ) // Determine whether it is a directory, return true if it is, otherwise return false;
$aFolders[] = 'dirs:' . $sFile . '
' ;
else
{
$fsize = @filesize( $dirs . $sFile ) ; //filesize() function returns the size of the specified file. Syntax: filesize(filename)

If ( !$fsize ) {
$fsize = 0 ;
}
If ( $fsize > 0 )
{
$fsize = round($fsize / 1024);//The round() function rounds floating point numbers. round(x,prec)
If ( $fsize < 1 ) $fsize = 1 ;
}

$aFiles[] = 'File name:' .$sFile . 'File size=' . $fsize . 'KB
' ;
}
}
}

//Naturally sort the directory

natcasesort( $aFolders ) ;//Naturally sort the array natcasesort(array)

foreach ( $aFolders as $sFolder )
{
echo $sFolder ;
}

// Sort files naturally
natcasesort( $aFiles ); // Natural 1-9, a-z sorting natcasesort(array);
foreach ( $aFiles as $sFiles )
{
echo $sFiles ;
}

}

/*
The calling method currently has directory
dirs:1
dirs:www.bKjia.c0m
File name: 1.php
File name: 2.php
*/

listDirFiles();

/*
The output result is
dirs:1
dirs:www.bKjia.c0m
File name: 1.php File size = 1KB
File name: 2.php File size = 2KB

Use function analysis
opendir
then the function returns a directory stream, otherwise it returns false and an error. You can hide error output by prepending "@" to the function name. Usage opendir(path,context)
is_dir
Determine whether it is a directory, return true if it is, otherwise return false;
readdir
The readdir() function returns the entry in the directory handle opened by opendir() Syntax: readdir(dir_stream)
filesize()
The function returns the size of the specified file. Syntax: filesize(filename)
natcasesort(array)
The natcasesort() function implements "natural sorting", that is, the sorting method of numbers from 1 to 9, and the sorting method of letters from a to z. The shorter one is given priority. This function is not case-sensitive. The index of the array is associated with the cell value