String Matching in Ubuntu is case-insensitive

As we all know, in shell string pattern matching, [a-z] indicates matching lowercase a to z, [A-Z] indicates matching uppercase A to Z, [0-9] indicates matching numbers 0 to 9, but ls [a-z] * is performed in Ubuntu. c and ls [A-Z] *. c has the same effect: the two sentences have the same effect, that is, they are case insensitive, but they run normally in other systems. Why? I do not know the cause of the search, but I have found a way to run LANG = C: When

As we all know, in shell string pattern matching, [a-z] indicates matching lowercase a to z, [A-Z] indicates matching uppercase A to Z, [0-9] indicates matching numbers 0 to 9, but ls [a-z] * is performed in Ubuntu. c and ls [A-Z] *. c has the same effect:

The two statements have the same effect, that is, they are case insensitive, but run normally in other systems. Why?

I do not know the reason for the search, but I have found a way to run LANG = C:

Of course, the scope of the LANG variable is limited to this terminal. When running on another terminal, the original result will still appear.

For more information about Ubuntu, see Ubuntu special page http://www.linuxidc.com/topicnews.aspx? Tid = 2