Question

I want to read string from standart input and output it in on console. I use this way:

char* cmdline;

do{
    scanf("%s\n", &cmdline);
    printf("%s\n", cmdline);
}while(cmdline != "quit");

But this doesn’t work. I have this error Segmentation fault (core dumped)

Answer 1

char* cmdline

is a pointer. You are not allocating space for storing the string.
You should do:

cmdline = malloc(size_of_string);

for allocating dynamic memory for storing the string.
Otherwise use an array of char instead of a pointer:

char cmdline[size_of_string];