switch case

static inline int printk_get_level(const char *buffer)
{
    if (buffer[0] == KERN_SOH_ASCII && buffer[1]) {
        switch (buffer[1]) {
        case '0' ... '7':
        case 'c':    /* KERN_CONT */
            return buffer[1];
        }
    }
    return 0;
}

switch case用法

case '0' ... '7':

case 0 ... 9: