linux sort order that I don't understand

Question

I notice the following sort outputs. Who understands why the \'.\' gets sorted in front the first time and at the end the second time?

I was trying to debug a program wh

Answer 1

It's not that "." comes before or after other characters - it's that it's not being examined at all; it's sorting purely based on the alphabetic characters.

In your first example, <end-of-string> sorts before E; in the second example, E sorts before T.

This behaviour is dependent on the locale settings for collation. You can influence this with environment variables, such as LC_COLLATE:

$ env LC_COLLATE=C sort
/mnt/x/Ed
/mnt/x/.T
^D
/mnt/x/.T
/mnt/x/Ed
$ env LC_COLLATE=en_US.UTF-8 sort
/mnt/x/Ed
/mnt/x/.T
^D
/mnt/x/Ed
/mnt/x/.T
$

Under the C locale, all ASCII characters are considered, and are sorted in their ASCII order; in many other locales punctuation is ignored - this is presumably what is causing the behaviour you're seeing.

You can examine your locale settings using the locale command.