LittleFS file.open doesnt work with variable filename

[xfpd]

@lupusc
I think he meant: "Try this link to read about a similar issue using srtcat():"

String Fundamentals - strcat() - const char* - char array

I am having trouble understanding the differences in my following two programs. The first one runs as expected. The second one does not compile. Thank you for your help. Compiles and runs: const char *constchar = "with a const char*";   void setup() {   char str[300];   strcpy (str,"these ");   strcat (str,"strings ");   strcat (str,"are ");   strcat (str,"concatenated ");   strcat (str, constchar);   puts (str); } void loop() {   // put your main code here, to run repeatedly: } Does not c…