Case sensitivity

Probably something of a trivial question for those who know: Can anyone out there confirm for me whether ANSI C is meant to be a case sensitive, or insensitive languge; and whether the Keil compiler...
Case sensitivity

Probably something of a trivial question for those who know: Can anyone out there confirm for me whether ANSI C is meant to be a case sensitive, or insensitive languge; and whether the Keil compiler...
Is ARM Keil IDE case-sensitive for all ARM assembly instructions? Is it indentation-sensitive?

Is ARM Keil IDE case-sensitive for all ARM assembly instructions? Is it indentation-sensitive?
Is ARM Keil IDE case-sensitive for all ARM assembly instructions? Is it indentation-sensitive?

Is ARM Keil IDE case-sensitive for all ARM assembly instructions? Is it indentation-sensitive?
file system case sensitive

I use Keil's file system on a NXP ARM with SD Card. I want to create filenames in lowercase, but when I initialise a string, e.g. strcpy(file_str, "myfile.dat") and do a fopen() with that name it creates...