freebsd | 易学教程

What is the equivalent of /proc/cpuinfo on FreeBSD v8.1?

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问题 What is the equivalent of Linux's /proc/cpuinfo on FreeBSD v8.1? My application reads /proc/cpuinfo and saves the information in the log file, what could I do to get similar information logged on FreeBSD? A sample /proc/cpuinfo looks like this: processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 23 model name : Intel(R) Xeon(R) CPU E5420 @ 2.50GHz stepping : 8 cpu MHz : 2499.015 cache size : 6144 KB fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes

史上最全的Linux 各个发行版本的优点、缺点、发展史介绍

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概述今天主要学习一下Linux 各个发行版本，看一下各个发现版本的发展史。什么是Linux？也许很多人会认为Linux不就是个操作系统么。其实严格来讲，Linux只是一个操作系统中的内核。内核是什么？内核建立了计算机软件与硬件之间通讯的平台，内核提供系统服务，比如文件管理、虚拟内存、设备I/O等。既然Linux只是一个内核。那么我们通常所说的Linux操作系统又是什么？我们通常所说的Linux，指 GNU/Linux ，即采用Linux内核的GNU操作系统。是的，操作系统的实际名称是GNU。什么是GNU？GNU代表GNU’s Not Unix。可以说是一个操作系统又可以说是一种规范。注释：什么是 GNU/Linux？ Linux 是一种计算机操作系统：一系列能让您与计算机进行交互操作并运行其它程序的程序。操作系统由多种基础程序构成。它们使计算机可以与用户进行交流并接受指令，读取数据或将其写入硬盘、磁带或打印机，控制内存的使用，以及运行其它软件。操作系统最重要的组成部分是内核。在 GNU/Linux 系统中，Linux 就是内核组件。而该系统的其余部分主要是由 GNU 工程编写和提供的程序组成。因为单独的 Linux 内核并不能成为一个可以正常工作的操作系统，所以我们更倾向使用“GNU/Linux” 一词来表达人们通常所说的 “Linux”。 Linux 是以

ETXTBSY and how to override it

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问题 I need to write to an executable file that is being executed, but I can't open it for writing. For example: #include <stdio.h> #include <fcntl.h> int main(int argc, char **argv) { int fd = open(argv[0], O_RDWR); if (fd == -1) perror(NULL); return 0; } % uname -rs FreeBSD 8.0-STABLE % ./example_ETXTBSY Text file busy There are some explanations what the heck is ETXTBSY in Linux, but nevertheless, is it possible to override this error? P.S. I'm not trying to write a virus. 回答1: If you are

MySQL Galera node not starting (aborting with Error 'WSREP: […]: 60: failed to reach primary view: 60 (Operation timed out)')

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问题 I am trying to setup three Galera nodes on FreeBSD 10 with MySQL 5.6.26 and VirtualBox. When I set up everything and run MySQL, it exits after some time and cannot start properly. Here is my log: 2015-10-22 15:23:24 9402 [Note] WSREP: Read nil XID from storage engines, skipping position init 2015-10-22 15:23:24 9402 [Note] WSREP: wsrep_load(): loading provider library '/usr/local/lib/libgalera_smm.so' 2015-10-22 15:23:24 9402 [Note] WSREP: wsrep_load(): Galera 3.5(rXXXX) by Codership Oy <info

mktime and tm_isdst

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问题 I saw a lot of different views so thought of asking here. I read man mktime : (A positive or zero value for tm_isdst causes mktime() to presume initially that summer time (for example, Daylight Saving Time) is or is not in effect for the specified time, respectively. A negative value for tm_isdst causes the mktime() function to attempt to divine whether summer time is in effect for the specified time. My question is, shouldn't tm_isdst be kept as -1 to let the system decide if its dst or not

Socket read with pcap

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问题 I have a socket bound to a NIC that I am using to capture packets in a pcap_loop. I have a separate process running that eventually does a "read" on that same device, but only after a unix local pipe is ready to be read. Is it correct to say that the read() on the device from the 2nd process will read everything that's ready, not just one packet at a time, even though my other process is set up to use pcap_loop to read a packet at a time? 回答1: I have a socket bound to a NIC that I am using to

Can a child process go <defunct> without its parent process dying?

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问题 kill - does it kill the process right away? I found my answer and I set up a signal handler for SIGCHLD and introduced wait in that handler. That way, whenever parent process kill s a child process, this handler is called and it calls wait to reap the child. - motive is to clear process table entry. I am still seeing some child processes going for a few seconds even without its parent process dying. - how is this possible? I am seeing this via ps . Precisely ps -o user,pid,ppid,command -ax

Can a child process go <defunct> without its parent process dying?

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How to close a non-blocking socket?

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问题 I believe that if we call close system call on a non-blocking socket it returns immediately, then how to handle the response? whether it is closed or not? in other words what is the behavior of the socket system call close on a non-blocking socket? 回答1: if we call close system call on a non-blocking socket it returns immediately The socket is always closed: the connection may still be writing to the peer. But your question embodies a fallacy: if you call close() on any socket it will return

Dovecot process limits

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问题 Sometimes my dovecot log return: service(imap-login): process_limit (512) reached, client connections are being dropped I can increase process_limit in dovecot config file, but i dont understand, how will it affect the system. How to diagnose why process limit is too high? I have around 50 users in my postfix+dovecot+roundcube system. My configuration: FreeBSD 10.0-stable Postfix 2.10 Dovecot 2.2.12 回答1: Dovecot have two modes for login processes. First is called secure mode when each client