Print process number (PID) _linux shell with interface provided by kernel

C File Printpid.c

Copy Code code as follows:

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/list.h>

static __init int printpid (void)//install module functions
{
struct Task_struct *task,*p;
struct List_head *ps;
int count=0;
PRINTK ("begin.\n");
task=&init_task;
List_for_each (Ps,&task->tasks)
{
P=list_entry (ps,struct task_struct,tasks);
count++;
PRINTK ("%d\t%s\n", P->pid,p->comm);
}
PRINTK ("Process counts:%d\n", count);
return 0;
}
static __exit void Exitpid (void)//unload function
{
PRINTK ("exit!\n");
}
Module_init (PRINTPID); The implemented function must be placed in the
Module_exit (EXITPID);

The Pid.ko file is generated after make.

And then use the following commands:

Copy Code code as follows:

#安装模块
sudo insmod pid

#显示日志信息
Dmesg

#显示挂载的挂载的所有模块
Lsmod

#卸载
sudo rmmod pid