procfs信息读取达成案例
发布时间：2021-12-18 15:46:29 所属栏目：教程 来源：互联网
导读：procfs信息读取实现案例： /********************************************** * Author: lewiyon@hotmail.com * File name: proc_sample.c * Description: create a file proc_example in the /proc, * which allows read. * Date: 2011-12-11 * Version: V1.
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procfs信息读取实现案例： /********************************************** * Author: lewiyon@hotmail.com * File name: proc_sample.c * Description: create a file "proc_example" in the /proc, * which allows read. * Date: 2011-12-11 * Version: V1.0 *********************************************/ #include <linux/kernel.h> /* We're doing kernel work */ #include <linux/module.h> /* Specifically, a module */ #include <linux/proc_fs.h> /* Necessary because we use proc fs */ #include <asm/uaccess.h> /* for get_user and put_user */ #define MESSAGE_LENGTH 80 #define PROC_NAME "proc_sample" unsigned int flag = 100; static struct proc_dir_entry *proc_sample; static struct proc_dir_entry *sample, *sample_r; /** * proc_read_data() * @page - buffer to write the data in * @start - where the actual data has been written in page * @offset - same meaning as the read system call * @count - same meaning as the read system call * @eof - set if no more data needs to be returned * @data - pointer to our soft state */ static int proc_read_data(char *page, char **stat, off_t off, int count, int *eof, void *data) { int len; len = sprintf(page, "jiffies = %ldn", jiffies); return len; } /* * 模块初始化 */ static int __init sample_init(void) { int ret = 0; /* * proc_mkdir(name, parent) * 在parent对应的目录下创建name目录 * 返回目录对应的proc_dir_dentry */ proc_sample = proc_mkdir(PROC_NAME, NULL); if (NULL == proc_sample) { ret = -ENOMEM; goto proc_sample_err; } /* * create_proc_entry(name, mode,parent) * 在parent对应的目录下创建name文件 * 返回目录对应的proc_dir_dentry */ sample = create_proc_entry("sample", 0644, proc_sample); if (NULL == sample) { ret = -ENOMEM; goto sample_err; } sample_r = create_proc_read_entry("sample_r", 0444, proc_sample, proc_read_data, NULL); if (NULL == sample_r) { ret = -ENOMEM; goto sample_r_err; } printk(KERN_INFO "Create samplen"); return ret; sample_r_err: remove_proc_entry("sample", proc_sample); sample_err: remove_proc_entry(PROC_NAME, NULL); proc_sample_err: return ret; } /* * 模块清理 */ static void __exit sample_exit(void) { remove_proc_entry("sample", proc_sample); remove_proc_entry("sample_r", proc_sample); remove_proc_entry(PROC_NAME, NULL); printk(KERN_INFO "Remove /proc/proc_samplen"); } module_init(sample_init); module_exit(sample_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("lewiyon <lewiyon@hotmail.com>"); 在/proc/创建文件目录proc_sampe，然后在其下创建了两个文件。其中sample_r可读取数据  （编辑：我爱故事小小网_铜陵站长网） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |
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