scandir - sort numeric filenames

Question

Done some searching, but can't seem to find the exact answer I'm looking for.

I'd like to pull in files with numbered filenames using 'scandir($dir)', but have them sort properly. For example, file names are:

1-something.ext

2-something-else.ext

3-a-third-name.ext

.

.

.

10-another-thing.ext

11-more-names.ext

The problem I'm having is that 10-a-fourth-thing.ext will show before 2-something-else.ext. I'd like to find a better way of solving this issue than introducing leading '0' in front of all file names.

Any thoughts? Thanks.

Answer 1

natsort does exactly what you need.

sort with SORT_NUMERIC will also work for filenames that start with numbers, but it will break if there are also names that have no numbers in front (all non-number-prefixed names will be sorted before number-prefixed names, and their order relative to one another will be random instead of alphabetic).

Answer 2

You can use sort like this:

sort($arr, SORT_NUMERIC); // asuming $arr is your array

Answer 3

If you want to reassign keys (which natsort does not do), use usort() combined with strnatcmp() or strnatcasecmp():

usort($arr, 'strnatcmp'); // Or 'strnatcasecmp' for case insensitive