Linux-TCP并发模型相关函数接口-014

2024-03-11 21:44
文章标签 linux 接口 函数 模型 并发 相关 tcp 014

本文主要是介绍Linux-TCP并发模型相关函数接口-014，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

1【TCP】多线程模型

相关函数接口已在前面章节介绍，这里不再赘述

源码示例（1）：

//【client.c】
int CreateTcpClient(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = connect(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to connect");return -1;}return sockfd;
}int main(void)
{int sockfd = 0;char tmpbuff[4096] = {"hello world"};int cnt = 0;ssize_t nsize = 0;sockfd = CreateTcpClient("192.168.1.183", 50000);while (1){memset(tmpbuff, 0, sizeof(tmpbuff));sprintf(tmpbuff, "hello world --- %d", cnt);cnt++;nsize = send(sockfd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return -1;}memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(sockfd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return -1;}printf("RECV:%s\n", tmpbuff);}close(sockfd);return 0;
}//【server.c】
int CreateListenSocket(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = bind(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to bind");return -1;}ret = listen(sockfd, 10);if (-1 == ret){perror("fail to listen");return -1;}return sockfd;
}void *HandleTcpClient(void *arg)
{char tmpbuff[4096] = {0};ssize_t nsize = 0;int confd = arg;while (1){memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(confd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return NULL;}else if (0 == nsize){return NULL;}sprintf(tmpbuff, "%s ----echo", tmpbuff);nsize = send(confd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return NULL;}}return NULL;
}int main(void)
{int sockfd = 0;int confd = 0;pthread_t tid;pthread_attr_t attr;sockfd = CreateListenSocket("192.168.1.183", 50000);pthread_attr_init(&attr);pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);while (1){confd = accept(sockfd, NULL, NULL);if (-1 == confd){perror("fail to accept");return -1;}pthread_create(&tid, &attr, HandleTcpClient, confd);}close(sockfd);return 0;
}

2【IO】模型

2.1阻塞IO

相关函数接口已在前面章节介绍，这里不再赘述

2.2非阻塞IO

源码示例（1）：

//【write.c】
int main(void)
{int fd = 0;char tmpbuff[4096] = {0};mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_WRONLY);if (-1 == fd){perror("fail to open");return -1;}while (1){gets(tmpbuff);write(fd, tmpbuff, strlen(tmpbuff));}close(fd);return 0;
}//【read.c】
int main(void)
{int fd = 0;int flags = 0;char *pret = NULL;ssize_t nsize = 0;char tmpbuff[4096] = {0};mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_RDONLY);if (-1 == fd){perror("fail to open");return -1;}flags = fcntl(fd, F_GETFL);flags |= O_NONBLOCK;fcntl(fd, F_SETFL, flags);flags = fcntl(0, F_GETFL);flags |= O_NONBLOCK;fcntl(0, F_SETFL, flags);while (1){memset(tmpbuff, 0, sizeof(tmpbuff));pret = gets(tmpbuff);if (pret != NULL){printf("STDIN:%s\n", tmpbuff);}memset(tmpbuff, 0, sizeof(tmpbuff));nsize = read(fd, tmpbuff, sizeof(tmpbuff));if (nsize > 0){printf("FIFO:%s\n", tmpbuff);}}close(fd);return 0;
}

2.3异步IO

源码示例（1）：

//【write.c】
int main(void)
{int fd = 0;char tmpbuff[4096] = {0};mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_WRONLY);if (-1 == fd){perror("fail to open");return -1;}while (1){gets(tmpbuff);write(fd, tmpbuff, strlen(tmpbuff));}close(fd);return 0;
}//【read.c】
int fd = 0;void handler(int signo)
{char tmpbuff[4096] = {0};ssize_t nsize = 0;memset(tmpbuff, 0, sizeof(tmpbuff));nsize = read(fd, tmpbuff, sizeof(tmpbuff));if (nsize > 0){printf("FIFO:%s\n", tmpbuff);}return;
}int main(void)
{int flags = 0;char *pret = NULL;ssize_t nsize = 0;char tmpbuff[4096] = {0};signal(SIGIO, handler);mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_RDONLY);if (-1 == fd){perror("fail to open");return -1;}flags = fcntl(fd, F_GETFL);flags |= O_ASYNC;fcntl(fd, F_SETFL, flags);fcntl(fd, F_SETOWN, getpid());while (1){memset(tmpbuff, 0, sizeof(tmpbuff));gets(tmpbuff);printf("STDIN:%s\n", tmpbuff);}close(fd);
}

2.4多路复用IO

2.4.1【select】

2.4.1.1函数原型
【int select(int nfds, fd_set *readfds, fd_set *writefds,fd_set *exceptfds, struct timeval *timeout);】
2.4.1.2函数功能
监听文件描述符集合中是否有文件描述编程ready状态
2.4.1.3函数参数
1.【nfds】：最大文件描述符的值+1 
2.【readfds】：读文件描述符集合
3.【writefds】：写文件描述符集合
4.【exceptfds】：其余文件描述符集合
5.【timeout】：等待的时长【NULL】：表示一直等待
2.4.1.4返回值
【成功】：返回文件描述符集合中的文件描述符个数
【失败】：返回【-1】
2.4.1.5常用的几个函数

1.【FD_CLR】

（1）函数原型：【void FD_CLR(int fd, fd_set *set);】
（2）函数功能: 将文件描述符fd从集合中清除 
（3）函数参数：【fd】：【set】：

（4）返回值：

2.【FD_ISSET】

（1）函数原型：【int  FD_ISSET(int fd, fd_set *set);】
（2）函数功能: 判断文件描述符fd是否仍在集合中
（3）函数参数：【fd】：【set】：
（4）返回值：

3.【FD_SET】

（1）函数原型：【int  FD_ISSET(int fd, fd_set *set);】
（2）函数功能: 将文件描述符fd加入到集合中
（3）函数参数：【fd】：【set】：
（4）返回值：

4.【FD_ZERO】

（1）函数原型：【int  FD_ISSET(int fd, fd_set *set);】
（2）函数功能: 将文件描述符集合清0
（3）函数参数：
【set】：
（4）返回值：

源码示例（1）：

//【write.c】
int main(void)
{int fd = 0;char tmpbuff[4096] = {0};mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_WRONLY);if (-1 == fd){perror("fail to open");return -1;}while (1){gets(tmpbuff);write(fd, tmpbuff, strlen(tmpbuff));}close(fd);return 0;
}//【read.c】
int main(void)
{int fd = 0;int flags = 0;char *pret = NULL;ssize_t nsize = 0;char tmpbuff[4096] = {0};fd_set rdfds;fd_set tmpfds;int ret = 0;mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_RDONLY);if (-1 == fd){perror("fail to open");return -1;}FD_ZERO(&rdfds);FD_SET(fd, &rdfds);FD_SET(0, &rdfds);while (1){tmpfds = rdfds;ret = select(fd+1, &tmpfds, NULL, NULL, NULL);if (-1 == ret){perror("fail to select");return -1;}if (FD_ISSET(fd, &tmpfds)){memset(tmpbuff, 0, sizeof(tmpbuff));read(fd, tmpbuff, sizeof(tmpbuff));printf("FIFO:%s\n", tmpbuff);}if (FD_ISSET(0, &tmpfds)){memset(tmpbuff, 0, sizeof(tmpbuff));gets(tmpbuff);printf("STDIN:%s\n", tmpbuff);}}close(fd);return 0;
}

源码示例（2）：

//【client.c】
int CreateTcpClient(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = connect(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to connect");return -1;}return sockfd;
}int main(void)
{int sockfd = 0;char tmpbuff[4096] = {"hello world"};int cnt = 0;ssize_t nsize = 0;sockfd = CreateTcpClient("192.168.1.183", 50000);while (1){memset(tmpbuff, 0, sizeof(tmpbuff));sprintf(tmpbuff, "hello world --- %d", cnt);cnt++;nsize = send(sockfd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return -1;}memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(sockfd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return -1;}printf("RECV:%s\n", tmpbuff);}close(sockfd);return 0;
}//【server.c】
int CreateListenSocket(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = bind(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to bind");return -1;}ret = listen(sockfd, 10);if (-1 == ret){perror("fail to listen");return -1;}return sockfd;
}int HandleTcpClient(int confd)
{char tmpbuff[4096] = {0};ssize_t nsize = 0;memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(confd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return -1;}else if (0 == nsize){return 0;}sprintf(tmpbuff, "%s ----echo", tmpbuff);nsize = send(confd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return -1;}return nsize;
}int main(void)
{int sockfd = 0;int confd = 0;fd_set rdfds;fd_set tmpfds;int maxfd = 0;int ret = 0;int i = 0;sockfd = CreateListenSocket("192.168.1.183", 50000);FD_ZERO(&rdfds);FD_SET(sockfd, &rdfds);maxfd = sockfd;while (1){tmpfds = rdfds;ret = select(maxfd+1, &tmpfds, NULL, NULL, NULL);if (-1 == ret){perror("fail to select");return -1;}if (FD_ISSET(sockfd, &tmpfds)){confd = accept(sockfd, NULL, NULL);if (-1 == confd){perror("fail to accept");FD_CLR(sockfd, &rdfds);close(sockfd);continue;}FD_SET(confd, &rdfds);maxfd = maxfd > confd ? maxfd : confd;}for (i = sockfd+1; i <= maxfd; i++){if (FD_ISSET(i, &tmpfds)){ret = HandleTcpClient(i);if (-1 == ret){fprintf(stderr, "handle client failed!\n");FD_CLR(i, &rdfds);close(i);continue;}else if (0 == ret){fprintf(stderr, "client disconnected!\n");FD_CLR(i, &rdfds);close(i);continue;}}}}close(confd);close(sockfd);return 0;
}

2.4.2【poll】

2.4.2.1函数原型
【int poll(struct pollfd *fds, nfds_t nfds, int timeout);】
2.4.2.2函数功能
监听文件描述符集合是否有事件发生
2.4.2.3函数参数
1.【fds】：监听文件描述符集合数组空间首地址
2.【nfds】：监听文件描述符集合元素个数
3.【timeout】：等待的时间【-1】： 一直等待

结构体说明：

struct pollfd {int   fd;/* file descriptor 监听的文件描述符*/short events;/* requested events 要监听的事件*/short revents;/* returned events 实际产生的事件*/
};
//结构体成员介绍
fd:监听的文件描述符
events:要监听的事件  POLLIN:是否可读  POLLOUT:是否可写
revents:实际产生的事件
2.4.2.4返回值
【成功】：返回产生事件的文件描述符个数
【失败】：返回【-1】

源码示例（1）：

//【write.c】
int main(void)
{int fd = 0;char tmpbuff[4096] = {0};mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_WRONLY);if (-1 == fd){perror("fail to open");return -1;}while (1){gets(tmpbuff);write(fd, tmpbuff, strlen(tmpbuff));}close(fd);return 0;
}//【read.c】
int main(void)
{int fd = 0;int flags = 0;char *pret = NULL;ssize_t nsize = 0;char tmpbuff[4096] = {0};struct pollfd fds[2];int nready = 0;mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_RDONLY);if (-1 == fd){perror("fail to open");return -1;}fds[0].fd = fd;fds[0].events = POLLIN;fds[1].fd = 0;fds[1].events = POLLIN;while (1){nready = poll(fds, 2, -1);if (-1 == nready){perror("fail to poll");return -1;}if (fds[0].revents & POLLIN){memset(tmpbuff, 0, sizeof(tmpbuff));read(fd, tmpbuff, sizeof(tmpbuff));printf("FIFO:%s\n", tmpbuff);}if (fds[1].revents & POLLIN){memset(tmpbuff, 0, sizeof(tmpbuff));gets(tmpbuff);printf("STDIN:%s\n", tmpbuff);}}close(fd);
}

源码示例（2）：

//【client.c】
int CreateTcpClient(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = connect(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to connect");return -1;}return sockfd;
}int main(void)
{int sockfd = 0;char tmpbuff[4096] = {"hello world"};int cnt = 0;ssize_t nsize = 0;sockfd = CreateTcpClient("192.168.1.183", 50000);while (1){memset(tmpbuff, 0, sizeof(tmpbuff));sprintf(tmpbuff, "hello world --- %d", cnt);cnt++;nsize = send(sockfd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return -1;}memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(sockfd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return -1;}printf("RECV:%s\n", tmpbuff);}close(sockfd);return 0;
}//【server.c】
int CreateListenSocket(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = bind(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to bind");return -1;}ret = listen(sockfd, 10);if (-1 == ret){perror("fail to listen");return -1;}return sockfd;
}int HandleTcpClient(int confd)
{char tmpbuff[4096] = {0};ssize_t nsize = 0;memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(confd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return -1;}else if (0 == nsize){return 0;}sprintf(tmpbuff, "%s ----echo", tmpbuff);nsize = send(confd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return -1;}return nsize;
}int InitFds(struct pollfd *fds, int maxlen)
{int i = 0;for (i = 0; i < maxlen; i++){fds[i].fd = -1;}return 0;
}int AddFd(struct pollfd *fds, int maxlen, int fd, short env)
{int i = 0;for (i = 0; i < maxlen; i++){if (fds[i].fd == -1){fds[i].fd = fd;fds[i].events = env;break;}}if (i == maxlen){return -1;}return 0;
}int DeleteFd(struct pollfd *fds, int maxlen, int fd)
{int i = 0;for (i = 0; i < maxlen; i++){if (fds[i].fd == fd){fds[i].fd = -1;break;}}return 0;
}int main(void)
{int sockfd = 0;int confd = 0;struct pollfd fds[1024];int nready = 0;int i = 0;int ret = 0;sockfd = CreateListenSocket("192.168.1.183", 50000);InitFds(fds, 1024);AddFd(fds, 1024, sockfd, POLLIN);while (1){nready = poll(fds, 1024, -1);if (-1 == nready){perror("fail to poll");return -1;}for (i = 0; i < 1024; i++){if (fds[i].fd == -1){continue;}if (fds[i].revents & POLLIN && fds[i].fd == sockfd){confd = accept(sockfd, NULL, NULL);if (-1 == confd){perror("fail to accept");DeleteFd(fds, 1024, sockfd);close(sockfd);continue;}AddFd(fds, 1024, confd, POLLIN);}else if (fds[i].revents & POLLIN && fds[i].fd != sockfd){ret = HandleTcpClient(fds[i].fd);if (-1 == ret){fprintf(stderr, "handle tcp client failed!\n");close(fds[i].fd);DeleteFd(fds, 1024, fds[i].fd);continue;}else if (0 == ret){fprintf(stderr, "client disconnected!\n");close(fds[i].fd);DeleteFd(fds, 1024, fds[i].fd);continue;}}}}close(sockfd);return 0;
}

2.4.3【epoll】

2.4.3.1函数原型

【int epoll_create(int size);】

2.4.3.2函数功能
创建一张内核事件表
2.4.3.3函数参数
【size】：事件的个数
2.4.3.4返回值
【成功】：返回文件描述符
【失败】：返回【-1】

2.4.4【epoll_ctl】

2.4.4.1函数原型

【int epoll_ctl(int epfd, int op, int fd, struct epoll_event *event);】

2.4.4.2函数功能

维护epoll时间表

2.4.4.3函数参数
1.【epfd】：事件表的文件描述符
2.【op】：【EPOLL_CTL_ADD】：添加事件【EPOLL_CTL_MOD】：修改事件【EPOLL_CTL_DEL】：删除事件
3.【fd】：操作的文件描述符
4.【event】：事件对应的事件

结构体说明：

typedef union epoll_data {void        *ptr;int          fd;uint32_t     u32;uint64_t     u64;
} epoll_data_t;struct epoll_event {uint32_t     events;      /* Epoll events */epoll_data_t data;        /* User data variable */
};
2.4.4.4返回值
【成功】：返回【0】 
【失败】：返回【-1】

2.4.5【epoll_wait】

2.4.5.1函数原型
【int epoll_wait(int epfd, struct epoll_event *events,int maxevents, int timeout);】
2.4.5.2函数功能
监听事件表中的事件
2.4.5.3函数参数
1.【epfd】：文件描述符
2.【events】：存放实际产生事件的数组空间首地址
3.【maxevents】：最多存放事件的个数
4.【timeout】：设定监听的时间（超过该时间则不再监听）【-1】：一直监听直到有事件发生
2.4.5.4返回值
【成功】：返回产生事件的文件描述符个数
【失败】：返回【-1】
【超时】：如果时间达到仍没有事件发生返回【0】

源码示例（1）：

//【write.c】
int main(void)
{int fd = 0;char tmpbuff[4096] = {0};mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_WRONLY);if (-1 == fd){perror("fail to open");return -1;}while (1){gets(tmpbuff);write(fd, tmpbuff, strlen(tmpbuff));}close(fd);return 0;
}//【read.c】
int main(void)
{int fd = 0;int flags = 0;char *pret = NULL;ssize_t nsize = 0;char tmpbuff[4096] = {0};int epfd = 0;struct epoll_event env;struct epoll_event retenv[2];int nready = 0;int i = 0;mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_RDONLY);if (-1 == fd){perror("fail to open");return -1;}epfd = epoll_create(2);if (-1 == epfd){perror("fail to epoll_create");return -1;}env.events = EPOLLIN;env.data.fd = fd;epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &env);env.events = EPOLLIN;env.data.fd = 0;epoll_ctl(epfd, EPOLL_CTL_ADD, 0, &env);while (1){nready = epoll_wait(epfd, retenv, 2, -1);if (-1 == nready){perror("fail to epoll_wait");return -1;}for (i = 0; i < nready; i++){if (retenv[i].data.fd == 0){memset(tmpbuff, 0, sizeof(tmpbuff));gets(tmpbuff);printf("STDIN:%s\n", tmpbuff);}else if (retenv[i].data.fd == fd){memset(tmpbuff, 0, sizeof(tmpbuff));read(fd, tmpbuff, sizeof(tmpbuff));printf("FIFO:%s\n", tmpbuff);}}}close(fd);
}

源码示例（2）：

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《usb接口驱动异常问题常用解决方案》当遇到USB接口驱动异常时，可以通过多种方法来解决，其中主要就包括重装USB控制器、禁用USB选择性暂停设置、更新或安装新的主板驱动等... usb接口驱动异常怎么办，USB接口驱动异常是常见问题，通常由驱动损坏、系统更新冲突、硬件故障或电源管理设置导致。以下是常用解决
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Linux命令之firewalld的用法

Linux命令之firewalld的用法

《Linux命令之firewalld的用法》：本文主要介绍Linux命令之firewalld的用法,具有很好的参考价值,希望对大家有所帮助,如有错误或未考虑完全的地方,望不吝赐教... 目录linux命令之firewalld1、程序包2、启动firewalld3、配置文件4、firewalld规则定义的九大
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Linux之计划任务和调度命令at/cron详解

Linux之计划任务和调度命令at/cron详解

《Linux之计划任务和调度命令at/cron详解》：本文主要介绍Linux之计划任务和调度命令at/cron的使用,具有很好的参考价值,希望对大家有所帮助,如有错误或未考虑完全的地方,望不吝赐教... 目录linux计划任务和调度命令at/cron一、计划任务二、命令{at}介绍三、命令语法及功能 :at
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Linux下如何使用C++获取硬件信息

Linux下如何使用C++获取硬件信息

《Linux下如何使用C++获取硬件信息》这篇文章主要为大家详细介绍了如何使用C++实现获取CPU,主板,磁盘,BIOS信息等硬件信息,文中的示例代码讲解详细,感兴趣的小伙伴可以了解下... 目录方法获取CPU信息：读取"/proc/cpuinfo"文件获取磁盘信息：读取"/proc/diskstats"文
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Linux内核参数配置与验证详细指南

Linux内核参数配置与验证详细指南

《Linux内核参数配置与验证详细指南》在Linux系统运维和性能优化中,内核参数（sysctl）的配置至关重要,本文主要来聊聊如何配置与验证这些Linux内核参数,希望对大家有一定的帮助... 目录1. 引言2. 内核参数的作用3. 如何设置内核参数3.1 临时设置（重启失效）3.2 永久设置（重启仍生效
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kali linux 无法登录root的问题及解决方法

kali linux 无法登录root的问题及解决方法

《kalilinux无法登录root的问题及解决方法》：本文主要介绍kalilinux无法登录root的问题及解决方法,本文给大家介绍的非常详细,对大家的学习或工作具有一定的参考借鉴价值,... 目录kali linux 无法登录root1、问题描述1.1、本地登录root1.2、ssh远程登录root2、
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shell编程之函数与数组的使用详解

shell编程之函数与数组的使用详解

《shell编程之函数与数组的使用详解》：本文主要介绍shell编程之函数与数组的使用,具有很好的参考价值,希望对大家有所帮助,如有错误或未考虑完全的地方,望不吝赐教... 目录shell函数函数的用法俩个数求和系统资源监控并报警函数函数变量的作用范围函数的参数递归函数shell数组获取数组的长度读取某下的
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MySQL高级查询之JOIN、子查询、窗口函数实际案例

MySQL高级查询之JOIN、子查询、窗口函数实际案例

《MySQL高级查询之JOIN、子查询、窗口函数实际案例》：本文主要介绍MySQL高级查询之JOIN、子查询、窗口函数实际案例的相关资料,JOIN用于多表关联查询,子查询用于数据筛选和过滤,窗口函... 目录前言1. JOIN（连接查询）1.1 内连接（INNER JOIN）1.2 左连接（LEFT JOI
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Linux ls命令操作详解

Linux ls命令操作详解

《Linuxls命令操作详解》通过ls命令,我们可以查看指定目录下的文件和子目录,并结合不同的选项获取详细的文件信息,如权限、大小、修改时间等,：本文主要介绍Linuxls命令详解,需要的朋友可... 目录1. 命令简介2. 命令的基本语法和用法2.1 语法格式2.2 使用示例2.2.1 列出当前目录下的文
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