On: You can list a directory containing 8M files, but not with ls

[acdha]

It’s not “ls -1” but “--sort=none” or “-U”.

[loeg → acdha]

"ls -f" in POSIX ls (which GNU ls also implements). Also, avoid "-F", which will stat each file.

[the_arun → acdha]

`ls | more` works too, right?

[loeg → the_arun]

At least with GNU ls, 'ls | more' does not disable sorting. It disables automatic color (which is important -- coloring requires 'stat(2)'ing every file in the directory).

[acdha → the_arun]

No - it still does all of the work to sort the entries, which is the slow part since it prevents the first entry from being displayed until the last has been retrieved.