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 a file using uppercase letters.
By chance I found that if I do a strcat after I initialised the string, e.g. strcat(file_str, "_anything") and then do a fopen() the file is created with lowercase letters.
Can someone explain this and how can I create files using lowercase letters?
I haven't access to the file system - and to my knowledge, the manual is only available with the license.
Anyway - when using VFAG and long file names, then the FAT file system will preserve case (but still be case-insensitive for name matches). So if the Keil implementation support long file names, then your concatenation will no longer represent a 8.3 name, and the exact name will be used.