errno

[Errno 14] PYCURL ERROR 7 - "couldn't connect to host" 转发：https://blog.csdn.net/weixin_43737815/article/details/89800349 关于[Errno 14] PYCURL ERROR 7 - "couldn’t connect to host"的解决方法 新的服务器指向原服务器的yum源，配置完成后进行 yum clean all操作和yum repolist 报错 [root@hadoop101 yum.repos.d]# yum repolist 已加载插件：fastestmirror, refresh-packagekit, security Determining fastest mirrors * extras: mirror.bit.edu.cn * updates: ap.stykers.moe http://192.168.1.100/cdrom/repodata/repomd.xml: [Errno 14] PYCURL ERROR 7 - "couldn't connect to host" 尝试其他镜像。 http://192.168.1.100/cdrom/repodata/repomd.xml: [Errno 14] PYCURL ERROR 7

Just curious. Which systems providing both EAGAIN and EWOULDBLOCK #define them as different values? There were some... http://www.gnu.org/s/hello/manual/libc/Error-Codes.html Portability Note: In many older Unix systems, this condition was indicated by EWOULDBLOCK, which was a distinct error code different from EAGAIN. To make your program portable, you should check for both codes and treat them the same. http://lists.parisc-linux.org/hypermail/parisc-linux/9895.html On some SysV systems EAGAIN != EWOULDBLOCK. I think we inherited the errno definitions from HPUX... Older AIX is such system too

匿名管道 一、特点 1.只适合单向通信。（如果需要双向通信，则需要两个匿名管道来进行完成） 2.只适合具有血缘关系的进程进行通信 3.管道是文件，生命周期随进程，进程结束后，文件就不在了 4.管道是基于字节流方式来进行通信的 5.父进程和子进程访问的公共资源叫做临界资源，所有临界资源都是需要被保护起来的，多个进程进行访问时必须要保证原子性。（任一时刻保证只有一个人访问） 6.管道内部自己已经实现同步性，能保证数据的一致性。 另外，进程间的通信的本质是：两个进程看到了一份公共的资源。 二、管道的创建 1.由父进程创建，子进程继承父进程的文件描述符，指向同一个文件，一个用来读，一个用来写，适当的关闭相应的文件读写端。 函数功能：创建管道，使得__pipe[0]指向文件的读端，_pipe[1]指向文件的写端 参数：一个含有两个整型元素的数组 返回值：0正常 -1管道创建失败 2.管道的大小 测试匿名管道的大小： #include<stdio.h> #include<unistd.h> #include<stdlib.h> int main() { int fd[ 2 ]; int count= 0 ; if (pipe(fd)< 0 ) { perror( "Fail to create pipe" ); exit ( 1 ); } while ( 1 ) { write(fd[ 1 ]

Per 7.5, [errno] expands to a modifiable lvalue175) that has type int, the value of which is set to a positive error number by several library functions. It is unspecified whether errno is a macro or an identifier declared with external linkage. If a macro definition is suppressed in order to access an actual object, or a program defines an identifier with the name errno, the behavior is undefined. 175) The macro errno need not be the identifier of an object. It might expand to a modifiable lvalue resulting from a function call (for example, *errno()). It's not clear to me whether this is

1 undefined reference to `pthread_create' 由于pthread 库不是 Linux 系统默认的库，连接时需要使用静态库 libpthread.a，所以在使用pthread_create()创建线程，以及调用 pthread_atfork()函数建立fork处理程序时，在编译中要加 -lpthread参数 。 例如：在加了头文件#include <pthread.h>之后执行 pthread.c文件，需要使用如下命令： gcc thread.c -o thread -lpthread 这种情况类似于<math.h>的使用，需在 编译时加 -m 参数。 pthread_create()和pthread_atfork()函数使用时应注意的问题： #include <pthread.h> void pmsg(void* p) { char *msg; msg = (char*)p; printf("%s ", msg); } int main(int argc, char *argv) { pthread_t t1, t2; pthread_attr_t a1, a2; char *msg1 = "Hello"; char *msg2 = "World"; pthread_attr_init(&a1); pthread_attr_init(&a2);

1.将 data.json 文件拷贝到 sellapp 目录下（与 index.html 同级） 模拟的数据请求是从 data.json 中读取数据，接下来就来编写这些接口。 2.在 webpack.dev.conf.js 中添加以下代码： 此次 开发过程需要去本地数据地址进行请求，而原版配置在 dev-server.js 中，新版 vue-webpack-template 已经删除 dev-server.js，改用webpack.dev.conf.js代替，所以配置本地访问在 webpack.dev.conf.js 里配置即可。这里使用 express 框架去写一个 nodeserver，也可以用 express-router 来编写这些接口请求。 1）先获取数据：获取data.json中的数据，再分别将商家，商品，评论数据写入相应变量中 1 const express = require('express') 2 const app = express() 3 4 const appData = require('../data.json') 5 const seller = appData.seller 6 const goods = appData.goods 7 const ratings = appData.ratings 2）编写路由及相应接口 解析：调用 get

I've been trying to properly convert a char array to a long with strtol , check if there was an overflow or underflow and then do an int cast on the long. Along the way, I've noticed a lot of code that looks like this if ((result == LONG_MAX || result == LONG_MIN) && errno == ERANGE) { // Handle the error } Why can you not just say if(errno == ERANGE) { // Handle the error } From my understanding, if an underflow or overflow occur, errno is set to ERANGE in both cases. So is the former really necessary? Could checking ERANGE alone be problematic? This how my code looks as of now char *endPtr;