Question

I have declared a variable as

const char* mode;

I want to get the value of mode from user. When I used

scanf("%s",mode)

I get a segmentation fault. Any suggestions?

Answer 1

You need to allocate memory to the pointer to be able to do something meaningful with it. Declare it as:

#define MAX_LENGTH 256
char *mode = malloc(MAX_LENGTH);

Also, it is better to have stack allocation, if the memory needed is not too big:
simply,

char mode[MAX_LENGTH];