&Flare

摘要： Let's take a look at a group of codes:#undef PDEBUG /* undef it, just in case */#ifdef SCULL_DEBUG# ifdef __KERNEL__ /* This one if debugging is on, and kernel space */# define PDEBUG(fmt, args...) printk( KERN_DEBUG "scull: " fmt, ## args)# else /* This one for user space */... 阅读全文

摘要： 先看下面一段代码，typedef struct CLIF_option_struct CLIF_option;struct CLIF_option_struct { const char *short_opt; const char *long_opt; const char *arg_name; const char *help_string; int (*function) (CLIF_option *optn, char *arg); void *data; int (*function_p... 阅读全文

摘要： 我们先来看一段shell脚本，[ $# -lt 2 ] && { echo "Usage: $0 target store_dir" >&2 exit 2}这段代码真的很精简，专业而成熟；其中包含的知识点有if条件，&&技巧，{}的块语块作用，重定向； 阅读全文

摘要： 刚阅读源代码，发现关于内存对齐的宏，越发的觉得自己该补一补数学知识了#define ALIGN_C(SIZE, boundary) \ (((SIZE) + (boundary) - 1) & ~((boundary) - 1))这个宏的作用是，将分配的SIZE大小的内存，按boundary对齐 阅读全文

摘要： APUE, Advanced Programming in the Unix Environment, is the most famous book for learning Linux or Unix-like programming.And I will study APUE in Linux/Ubuntu 12.04 LTS. Suppose your current working directory is $HOME(on my machine, HOME=/home/rex),Follow these steps,1. The source codes on the book c 阅读全文