linux Kernel module简单模拟ps指令输出_linux kernel %ps-优快云博客

本文链接：https://blog.youkuaiyun.com/qq123386926/article/details/50543038

本文介绍了如何在Linux内核模块中实现类似ps指令的功能，通过遍历进程并使用深度优先搜索策略，详细讲解了代码实现过程，并提供了示例代码链接。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

一、方法

/* sched.h */
Struct task_struct {
    …
    list_head children;
    list_head sibling;
    …
};
 
1）
/* traver every process */
struct task_struct *task;
for_each_process( task )
{
    /* handle the process info */
}
 
2）
/* traver the children of the init process */
struct task struct *task;
struct list head *list;
list for each(list,&init_task.children) {
    task = list entry(list, struct task struct, sibling);
    /* task points to the next child in the list */
}

二、实现

1）简单遍历所有进程，直接使用for_each_process()即可；

do_ps( void )
{
   struct task_struct *task;
 
   printk( KERN_INFO "%-5s %-9s %s\n", "PID","STATE", "CMD" );
   for_each_process( task )
   {
       printk( KERN_INFO "%-5d %-9c %s\n", task->pid,get_status_text( task->state ), task->comm );
   }
 
   return 0;
}

2）采用深度优先的方式遍历，借助数据结构——栈；

（1）将初始进程压栈；

（2）如果栈不为空，进程出栈；若为空跳到（4）；

（3）将出栈进程的子进程压栈，返回（2）；

（4）结束进程遍历；

do_ps_dfs( void)
{
    struct task_struct *task;
    struct list_head   *list;
    struct process_node *pCur;
 
    printk( KERN_INFO"\n\n\n\n\n\n\n" );
    printk( KERN_INFO "%-5s %-9s%s\n", "PID", "STATE", "CMD" );
    push_process( &init_task );
    while( ( pCur = pop_process() ) )
    {
        printk( KERN_INFO "%-5d %-9c%s\n", pCur->process->pid, get_status_text(pCur->process->state ), pCur->process->comm );
        list_for_each( list, &( pCur->process->children) )
        {
            task = list_entry( list, structtask_struct, sibling );
            push_process( task );
        }
        kfree( pCur );
    }
    return 0;
}

三、示例代码

http://download.youkuaiyun.com/detail/qq123386926/9410413