在面对整数时,要留心整数溢出的情况. 在探索一个数有多少个除数的程序中,原本我们只要累加自然数到大于根号N停止即可. 不过因为计算机的整数范围的限制,我们需要判断是否i*i<(i-1)*(i-1). 如果发生这种情况,说明整数溢出了~…

SAP MM PIR里的Lower Limit & Upper Limit 在PIR的价格的detail数据里,有2个字段:Lower Limit和Upper Limit.在今天之前,笔者从未注意过这2个字段,也没有用过它们. 今天某同行在微信上问我是否可以通过PIR里的设置来实现采购订单价格最高限额的控制,并提醒我PIR有这2个字段.这才引起了笔者对这2个字段的好奇与关注. 这2个字段是做什么用的?能不能控制后续的PO里的净价是在这2个字段值之间?比如控制PO的价格不能超过Upper Limi…

题目:Prediction of an Upper Limit for the Fraction of Interprotein Cross-Links in Large-Scale In Vivo Cross-Linking Studies 期刊:Journal of Proteome Research 发表时间:July 3, 2019 DOI:10.1021/acs.jproteome.9b00189 作者及单位: Andrew Keller——Department of Genome S…

DecimalFormat继承自NumberFormat,可以使用它将十进制的数以不同形式格式化为字符串形式,可以控制前导和尾随0.前缀.后缀.分组(千).小数分隔符等,如果要更改格式符号(例如小数点分隔符). 它有各种各样的设计使其能够解析和格式化数字的特征区域设置,包括对西方.阿拉伯和印度数字的支持.它也支持不同类型的数字,包括整数(123),定点数字(123.4),科学符号(1.23 e4),百分比(12%),以及货币金额(123美元).所有这些都可以本地化. 可以将其DecimalFor…

To keep the TCP/IP stack from taking all resources on the computer, there are different parameters that control how many connections it can handle. If running applications that are constantly opening and closing connections (P2P), or are providing a…

转载地址:http://smallvoid.com/article/winnt-tcpip-max-limit.html To keep the TCP/IP stack from taking all resources on the computer, there are different parameters that control how many connections it can handle. If running applications that are constant…

Introduction Log files are files that contain messages about the system, including the kernel, services, and applications running on it. There are different log files for different information. For example, there is a default system log file, a log f…

#    WELCOME TO SQUID 3.0.STABLE26#    ----------------------------##    This is the default Squid configuration file. You may wish#    to look at the Squid home page (http://www.squid-cache.org/)#    for the FAQ and other documentation.##    The def…

catalog . 为什么要监控文件系统 : hotplug . udev . fanotify(fscking all notification system) . inotify . code example 1. 为什么要监控文件系统 在日常工作中,人们往往需要知道在某些文件(夹)上都有那些变化,比如: . 通知配置文件的改变 . 跟踪某些关键的系统文件的变化 . 监控某个分区磁盘的整体使用情况 . 系统崩溃时进行自动清理 . 自动触发备份进程 . 向服务器上传文件结束时发出通知 . 杀软…

在Linux中,给kernel传递参数以控制其行为总共有三种方法: 1.build kernel之时的各个configuration选项. 2.当kernel启动之时,可以参数在kernel被GRUB或LILO等启动程序调用之时传递给kernel. 3.在kernel运行时,修改/proc或/sys目录下的文件. 这里我简单讲的就是第二种方式了,kernel在grub中配置的启动参数. 首先,kernel有哪些参数呢? 在linux的源代码中,有这样的一个文档Documentation/kern…

http://anandtech.com/show/2549 Now that NVIDIA’s has announced its newest GPU architecture (the GeForce GTX 200 series), interesting architectural details are popping up on the web. The best writeup I’ve found is by AnandTech. In the past, such detai…

(一)SSL/TLS协议运行机制的概述 一.作用 不使用SSL/TLS的HTTP通信,就是不加密的通信.所有信息明文传播,带来了三大风险. (1) 窃听风险(eavesdropping):第三方可以获知通信内容. (2) 篡改风险(tampering):第三方可以修改通信内容. (3) 冒充风险(pretending):第三方可以冒充他人身份参与通信. SSL/TLS协议是为了解决这三大风险而设计的,希望达到: (1) 所有信息都是加密传播,第三方无法窃听. (2) 具有校验机制,一旦被篡改,通…

Status of This Memo This document specifies an Internet standards track protocol for the   Internet community, and requests discussion and suggestions for   improvements.  Please refer to the current edition of the "Internet   Official Protocol Stand…

File I/O Introduction     We'll start our discussion of the UNIX System by describing the functions availablefor file I/O-open a file, read a file, write a file, and so on. Most file I/O on a UNIX system can be performed using only five functions: open, re…

[OS]NMON的简介和使用 目前NMON已开源,以sourceforge为根据地,网址是http://nmon.sourceforge.net. 1. 目的 本文介绍操作系统监控工具Nmon的概念.使用方式及使用参数.指导运维人员通过nmon工具监视AIX/Linux操作系统资源使用情况,收集监控结果及产生的数据文件,制作相关系统性能分析报告. 2. Nmon简介 Nmon (Nigel’s Monitor)是由IBM 提供.免费监控 AIX 系统与 Linux 系统资源的工具.该工具可将服务…

1. Detecting Performance Issues 2. Scripting Strategies 3. The Benefits of Batching 4. Kickstart Your Art 5. Faster Physics 6. Dynamic Graphics 7. Masterful Memory Management 8. Tactical Tips and Tricks 1. Detecting Performance Issues  The Unity Prof…

http://wiki.nginx.org/HttpLuaModule#Directives Name ngx_lua - Embed the power of Lua into Nginx This module is not distributed with the Nginx source. See the installation instructions. Status This module is under active development and is production…

http://www.chemie.fu-berlin.de/chemnet/use/info/libc/libc_21.html A signal is a software interrupt delivered to a process. The operating system uses signals to report exceptional situations to an executing program. Some signals report errors such as…

Finalization 和弱引用.软引用.虚引用 Finalization and Weak, Soft, and Phantom References Some applications interact with garbage collection by using finalization and weak, soft, or phantom references. These features can create performance artifacts at the Java…

转自:https://blogs.dropbox.com/tech/2017/09/optimizing-web-servers-for-high-throughput-and-low-latency/ This is an expanded version of my talk at NginxConf 2017 on September 6, 2017. As an SRE on the Dropbox Traffic Team, I’m responsible for our Edge n…

在Linux中,给kernel传递参数以控制其行为总共有三种方法: 1.build kernel之时的各个configuration选项. 2.当kernel启动之时,可以参数在kernel被GRUB或LILO等启动程序调用之时传递给kernel. 3.在kernel运行时,修改/proc或/sys目录下的文件. 这里我简单讲的就是第二种方式了,kernel在grub中配置的启动参数. 首先,kernel有哪些参数呢? 在linux的源代码中,有这样的一个文档Documentation/kern…

1. CentOS系统安装openresty 你可以在你的 CentOS 系统中添加 openresty 仓库,这样就可以便于未来安装或更新我们的软件包(通过 yum update 命令).运行下面的命令就可以添加我们的仓库: $ sudo yum install yum-utils $ sudo yum-config-manager --add-repo https://openresty.org/package/centos/openresty.repo 然后就可以像下面这样安装软件包,比如…

/****************************************************************************** ** This file is an amalgamation of many separate C source files from SQLite ** version 3.14.1. By combining all the individual C code files into this ** single large file…

F. Bear and Fair Set time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Limak is a grizzly bear. He is big and dreadful. You were chilling in the forest when you suddenly met him. It's very u…

题目描述: 1015. Jill's Tour Paths Constraints Time Limit: 1 secs, Memory Limit: 32 MB Description Every year, Jill takes a bicycle tour between two villages. There are different routes she can take between these villages, but she does have an upper limit…

超文本传输协议版本 2 IETF HTTP2草案(draft-ietf-httpbis-http2-13) 摘要 本规范描述了一种优化的超文本传输协议(HTTP).HTTP/2通过引进报头字段压缩以及多路复用来更有效利用网络资源.减少感知延迟.另外还介绍了服务器推送规范. 本文档保持对HTTP/1.1的后向兼容,HTTP的现有的语义保持不变. 1 介绍 The Hypertext Transfer Protocol (HTTP) is a wildly successful protocol.…

1. ARCHIVE_LAG_TARGET forces a log switch after the specified amount of time elapses.有效值为0(disabled)或 [ 60,7200 ] 2. SEC_PROTOCOL_ERROR_FURTHER_ACTION specifies the further execution of a server process when receiving bad packets from a possibly mali…

Simple SDK for capturing, recording and streaming video and audio from web-cams on Windows OS by Windows Media Foundation. Download CaptureManagerSDK-1.0.0.zip - 1.1 MB Download CaptureManagerSDK-1.1.0.zip - 1.1 MB Download CaptureManagerSDK-1.2.0_be…

Keep In Touch Problem Description   There are n cities numbered with successive integers from 1 to n in Byteland. Also, there are m one-way roads connecting the cities. The starting point of the i-th road is ui while the ending point is vi. There are…

Information Disturbing Problem Description   In the battlefield , an effective way to defeat enemies is to break their communication system.The information department told you that there are n enemy soldiers and their network which have n-1 communica…