What is “…” in switch-case in C code

Question

Here is a piece of code in /usr/src/linux-3.10.10-1-ARCH/include/linux/printk.h:

static inline int printk_get_level(const char *buffer)
{
  if (         


        

Answer 1

case '0'...'7': is case ranges Speciacation in gcc.

Range specification for case statement.

Write spaces around the ..., for otherwise it may be parsed wrong when you use it with integer values

case '0' or case '1' or case '3' and so on case '7':
or case 'b' :
just return buffer[1];