存档在 2018年4月

怎样让进程在后台运行

2018年4月21日

参考:https://www.ibm.com/developerworks/cn/linux/l-cn-nohup/

需求:用 telnet/ssh 登录了远程的 Linux 服务器,如何让命令提交后不受本地关闭终端窗口/网络断开连接的干扰。

hangup 名称的来由:在 Unix 的早期版本中,每个终端都会通过 modem 和系统通讯。当用户 logout 时,modem 就会挂断(hang up)电话。 同理,当 modem 断开连接时,就会给终端发送 hangup 信号来通知其关闭所有子进程。

场景:如果只是临时有一个命令需要长时间运行,什么方法能最简便的保证它在后台稳定运行呢?

方法:当用户注销(logout)或者网络断开时,终端会收到 HUP(hangup)信号从而关闭其所有子进程。因此,我们的解决办法就有两种途径:要么让进程忽略 HUP 信号,要么让进程运行在新的会话里从而成为不属于此终端的子进程。

1. nohup

顾名思义,nohup 的用途就是让提交的命令忽略 hangup 信号。

“nohup – run a command immune to hangups, with output to a non-tty”

只需在要处理的命令前加上 nohup 即可,标准输出和标准错误缺省会被重定向到 nohup.out 文件中。可在结尾加上”&”来将命令同时放入后台运行,也可用”>filename 2>&1″来更改缺省的重定向文件名。

nohup ping www.ibm.com &

2. setsid

nohup 能通过忽略 HUP 信号来使进程避免中途被中断,如果进程不属于接受 HUP 信号的终端的子进程,那么也就不会受到 HUP 信号的影响。setsid 就能帮助做到这一点。

“setsid – run a program in a new session”

只需在要处理的命令前加上 setsid 即可。

setsid ping www.ibm.com

值得注意的是,上例中我们的进程 ID(PID)为31094,而它的父 ID(PPID)为1(即为 init 进程 ID),并不是当前终端的进程 ID。请将此例与nohup 例中的父 ID 做比较。

怎样制作一个数据库类网站

2018年4月21日

【Database Application Platform v1.4.5】

Databased is a powerful database application platform. It allows you to turn a MySQL database into a beautiful and user-friendly online application. Use it to create online spreadsheets, maintain customer data, inventory data, sales data, etc.

官网:http://databasedapp.com/
演示:http://databasedapp.com/demo/
购买: http://codecanyon.net/item/database-application-platform/6957496

资源:https://scriptznull.nl/threads/database-application-platform-v1-4-5.32622/
资源:http://kings-theme.com/codecanyon-database-application-platform-v1-4-5/
下载:https://tusfiles.net/6w481y64ugwg

【Database Application Platform v1.4.5】

【PDO Crud v2.6 – Advanced PHP CRUD application (Database Management System)】

PDOCrud is an advance PHP based CRUD application. It supports Mysql, Pgsql and Sqlite database. You can use PDOCrud to generate both frontend and backend of your application. By writing just 2-3 lines of code only, you can perform insert/update/delete and select operation. You just to need to create object and call for render function for that table and everything will be generated automatically.

官网:http://pdocrud.com/
演示:http://pdocrud.com/demo/
购买:https://codecanyon.net/item/pdocrud-advanced-php-crud-application-database-management-system/17674879

资源:https://kingdomofsinces.com/download-codecanyon-pdo-crud-v2-6-advanced-php-crud-application-database-management-system-free/
下载:https://userscloud.com/qipm7x025ccn

怎样从GooglePlay直接下载到APK 文件

2018年4月20日

有了APK Downloader,那就可以直接下载Google Play中的应用APK文件。

官网:http://apps.evozi.com/APK-downloader/

在输入框里填写Google Play的应用地址,回车之后就有直接下载的那绿色按钮。

另有2个镜像搜索引擎:

https://www.apkmirror.com
https://www.apklinker.com

翻译:JustDropped.com是如何通过批量注册域名实现盈利

2018年4月19日

参考:https://domainnamewire.com/2013/08/08/how-justdropped-com-profits-from-domain-names-by-focusing-on-volume/

《How JustDropped.com profits from domain names by focusing on volume》

Behind a popular expired domain site lies a business model of selling lots of domain names for under $100.

JustDropped.comThere are a handful of people and companies that make a living buying and selling domain names.

There are some, like Frank Schilling, who make money selling a small percentage of their portfolio each year for very high prices.

There are others, like NameMedia, who sell a bigger, but still small, percentage of their portfolio with a typical price of under $2,000.

Then there’s Dan Rubin, founder of JustDropped.com, who sells a big percentage of his domain portfolio, but mostly for under $100.

Rubin’s story began in 2003. He was working full time, but started the expired domain search site JustDropped.com on the side that year.

Back then the options for expiring domain data were rather limited. He had one big competitor who suddenly decided to start charging for its search service. That sent hundreds of users a day over to JustDropped, where they could search for domains at no charge.

Rubin made money from affiliate links to domain name registrars. When a visitor found a domain they liked that had “just dropped”, they’d click on a link to buy it and Rubin would pocket a commission.

It was a good business model, but Rubin saw another opportunity. He realized he had a knack for finding good dropping domains. What if he were to acquire domain names himself and offer them to customers at prices typically found with domain backordering service?

He sent out a newsletter with around 20 domains with buy-it-now prices of $70 or so. The response was phenomenal.

Revenue from domain sales quickly dwarfed how much JustDropped.com made from commissions. Although it’s a bit under-the-rader, JustDropped had perhaps one of the first domain sales newsletters. Its readership has grown to 75,000 and there’s now a companion iPhone app.

Part of the trick to making this low priced domain business model work is only paying $8 when registering expired domains rather than paying a backorder service to do it for much more. Rubin did this with the help of backordering software DNWare. As an affiliate of DNWare, he was the software creator’s top sales channel. He eventually bought the DNWare business.

The second key is knowing which domains to go after. Although many of the best domains are sold through competitive auctions at NameJet and SnapNames, Rubin realized he was particularly good at spotting brandable domains that could be quickly resold.

“A big part of my time is spent analyzing the drops,” Rubin said. “A lot of people just look at the metrics. Those types of domains [with good domain metrics] are highly competitive because everyone’s looking at the same metrics.”

Rubin’s business continued to grow. In 2008, he quit his job of 20 years to focus solely on the domain business.

In 2009, he was approached by Rob Monster about selling JustDropped to Epik. The two struck a deal, but it later fell through.

Rubin hasn’t looked back. He continues to buy domains for about $8 and sell them for 10x that.

Is there really a business selling domains for under $100?

Rubin points out that the ROI on buying a domain for $8 and selling it for $80 is better than buying one for $1,000 and selling it for $2,000.

And, to be fair, he does sell some of his inventory for more. He holds on to domains that don’t sell right away and adds them to domain marketplaces. 75% of them have buy-it-now prices.

Rubin is playing a volume game, and it’s not easy. But by making shrewd purchases and quickly flipping them, his business has been able to thrive along with some of the bigger guys who make headlines every day.

网站: Zotero

2018年4月19日

首页:https://www.zotero.org/

参考:http://dietsolutionforyou.org/zotero-or-citeulike-or-connotea-or-2collab-or-mekentosj-papers-or-endnote-alternative-or-refworks-alternative-or-refman-alternative-or-orbiomedexperts-com-or-academia-edu-or-epernicus-or-labmeeting-or/
参考:https://www.linux.com/news/zotero-seriously-useful-research-tool
参考:https://scholarlykitchen.sspnet.org/2013/01/24/mendeley-connotea-and-the-perils-of-free-services/

文档:http://webs.wofford.edu/whisnantdm/Training/Citations/Zotero.pdf

Slogan: Zotero – Your personal research assistant

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