[Linux] Kernel函式庫

Kernel

●忙碌等待(busy wait)
會占住CPU,不讓CPU處理其他事,不適合長時間使用.

#include <linux/delay.h>
void mdelay(unsigned long msecs); //毫秒
void udelay(unsigned long msecs); //微秒
void ndelay(unsigned long msecs); //奈秒


●不忙碌等待(non-busy wait)

#include <linux/delay.h>
void ssleep(unsigned int seconds);
void msleep(unsigned int mecs);
unsigned long msleep_interruptible(unsigned int mecs);

[C] 函式庫(Library)

●ASCII ->Hex

unsigned long int strtoul(const char *str, char **endptr, int base)

str: string

endptr:

base: 這是基數，2~36，或者是特殊值0。

●取絕對值

#include <stdlib.h>

int abs (int j);

●讓程式空轉以達到延遲

__NOP();

●小寫字母轉大寫
int toupper(int c);

access

http://naeilproj.blogspot.com/2015/08/linux-c-c.html

bswap_32

https://man7.org/linux/man-pages/man3/bswap.3.html

dump_stack();

#include <linux/kprobes.h>

#include <asm/traps.h>

●stroul

char ptr; 

u32 value stroul("1234", ptr, 10);

把string 1234轉成value 1234

10表10進位(base)

●atoi

value → string

●strcat

●sscanf

●strstr

char *p strstr("abcde", "de")

在abcde中找de, *p為d的位置

●snprintf / fprintf

https://iamcgod.blogspot.com/2023/03/c-fprintf-sprintf.html