Linux whole-line sort does not sort correctly

Question

I want to whole-line sort a file with the linux command sort.

My file cat hello

#_
*
#1

When run with sort hello

#_
*
#1

Because # stands before * in asccii table, my expected result is

#_
#1
*

Is there anyone can explain me why? Thank you.

Answer 1

By default gnu sort doesn't sort bytewise, that is, won't follow the order in ascii table. Check this example:

kent$  cat f1
a
b
c
A
B
C

kent$  sort f1          
a
A
b
B
c
C

If you want the sort to sort bytewise, you can set the LC_ALL:

kent$  LC_ALL=C    
kent$  sort f1
A
B
C
a
b
c

Thus, with LC_ALL=C, you get your expected output too.

kent$  cat f
#_
*
#1

kent$  sort f
#1
#_
*

update

I just checked the man page, it states this literally as well:

* WARNING * The locale specified by the environment affects sort order. Set LC_ALL=C to get the traditional sort order that uses native byte values.