How to make the linux/macOS command " .ls >> files.txt " run at php using exec()?

I Just wanna to list all files and subdirectories and store this list in file ... in MS-DOS, Linux and MAC OS, the command line -- .ls( or .dir) >> files.txt -- would give me what I want ... But, how to make a php script run it ?

if I use (on php)

exec ('ls >> files.txt');

I will get a error like this: Warning: Unexpected character in input: '' (ASCII=28) state=0 in /Applications/XAMPP/xamppfiles/htdocs/DjUtilities/makeLabels.php on line 29

...

please, any idea ???

The use of this will be to set labels with the musics in a cd, here, divided by directories... I wanna to get any cd's (subdirectories) and list the files (the tracks) to make a label with the track list....

So, The initial idea was to create a file with these data and then, process the data to make the labels... any better way to do that will be very welcome !!

Solution

You can use 'opendir' and 'readdir' to do that, both native php commands...