对于数据库编程我还是选择了Task[Either[E,Option[A]]]这种类型作为数据库操作运算的统一类型。...在Task[Either[E,Option[A]]]这个复合类型中的组成类型Option[A],Either[E,A]实际上是包嵌A类型元素的不同管道，各自可以独立支持Monadic编程，如下： object...如果我们把这两个类型在for-comprehension里结合使用： object session22 extends App { val ovalue: Option[Int] = Some(10...当然，这是因为Option,Either是不同的Monad。...注意复合型Monad Transformer的组成是由内向外反向的：Option[A]是最内的元素，那么在合成时就摆在最外。
OptionT实际上是用来构建M[Option[A]]，在我们的例子里就是Either[Option[A]]。...在上面的例子就变成了: OptionT[Either,A](run: Either[Option[A]])，这个Either[Option[A]]就是我们的目标类型。...我们把Either和Option叠加后按照不同顺序可以产生Either[Option[A]]或者Option[Either[A]]两种结果类型，所以叠加顺序是非常重要的，因为这两种类型代表着截然不同的意义...而且我们需要把Either和Option升格成OptionT[Either,A]，看下面的示范： 1 type Error[A] = \/[String, A] 2 type Result[A] =...point、OptionT.optionT、liftM分别对String，Option，Either进行类型升格形成Result[String] >>> OptionT[Error,String]。
You can either disable the module by using –without-http_rewrite_module option, or install the PCRE...You can either disable the module by using –without-http_gzip_module option, or install the zlib library...You can either disable the module by using –without-http-cache option, or install the...至此，nginx 执行成功了 ———————————————————————————————————————————————————————————————————————————— 下来配置环境变量在/...proxy_connect_timeout 10; } error_page 500 502 503 504 /50x.html; location =
scala标准库提供了一个Either类型，它可以说是Option的升级版。...与Option相同，Either也有两种状态：Left和Right，分别对应Option的None和Some，不同的是Left可以返回一个值。我们通常用这个值来表述异常信息。...如此能够方便把Either功能整合到FP编程中去。...这与Option功能相当。...\/在for-comprehension里的运算行为与Option一致。不过这个\/写法比较别扭。
/configure: error: the HTTP rewrite module requires the PCRE library. ...You can either disable the module by using --without-http_rewrite_module option, or install the PCRE.../configure: error: the HTTP gzip module requires the zlib library. ...You can either disable the module by using --without-http_gzip_module option, or install the zlib...Java jzlib-demo.x86_64 : Examples for jzlib jzlib-javadoc.x86_64 : Javadoc for jzlib perl-Compress-Raw-Zlib.x86
在之前的文章中我们提到了Option，scala中Option表示存在0或者1个元素，如果在处理异常的时候Option就会有很大的限制，因为Option如果返回None，那么我并不知道具体的异常到底是什么...顾名思意，Either表示或者是这一个元素或者是那个元素。这样在异常处理的时候就非常有用了。...Either怎么在代码中消除程序错误，将错误封装在Either中。...) java.lang.NumberFormatException: For input string: "x" 先看上面的例子，我们定义了一个addInts方法，接收两个String参数，并将其转换为...(java.lang.NumberFormatException: For input string: "x") 按照上面的设计，Either封装好了异常，不会影响程序的正常运行，而且可以返回具体的错误信息
--with-file-aio \ --with-http_v2_module 错误排查 错误1 checking for OS Linux 3.10.0-327.36.1.el7.x86..._64 x86_64 checking for C compiler … not found ..../configure: error: the HTTP rewrite module requires the PCRE library.You can either disable the module.../configure: error: SSL modules require the OpenSSL library.You can either do not enable the modules,...Defaults secure_path="/etc/nginx/sbin:..." systemd 在 /etc/systemd/system/ 下增加 nginx.service 文件，以下路径根据实际自己修改
可能出现错误 在配置信息....You can either disable the module by using –without-http-cache option, or install the OpenSSL library...You can either disable the module by using –without-http_gzip_module option, or install the zlib library...into the system, or build the zlib library statically from the source with nginx by using –with-zlib= option...You can either do not enable the module or install the library.
可能出现错误在配置信息....You can either disable the module by using --without-http-cache option, or install the OpenSSL library...You can either disable the module by using –without-http_gzip_module option, or install the zlib library...system, or build the zlib library statically from the source with nginx by using –with-zlib= option...You can either do not enable the module or install the library.
/configure: error: the HTTP rewrite module requires the PCRE library....You can either disable the module by using --without-http_rewrite_module option, or install the PCRE.../configure: error: the HTTP gzip module requires the zlib library....You can either disable the module by using --without-http_gzip_module option, or install the zlib library...在 nginx-1.16.1 目录下执行 make 编译 make 5. 在 nginx-1.16.1 目录下执行 make install make install
Unlike telnet(1), nc scripts nicely, and separates error messages onto standard error instead of sending...It is an error to use this option without the -l option....It is an error to use this option in conjunction with the -p, -s, or -z options....It is an error to use this option in conjunction with the -l option....It is an error to use this option in conjunction with the -l option.
-c 要补全的命令 -p 命令路径 -e -s 短参数 -h -l 长参数 --help -o old style long option -a 添加子命令 -f 不列出文件 -r -x -f and...· -x or --exclusive implies both -r and -f....If the shell is not in interactive mode, an error is returned....When erasing completions, it is possible to either erase all completions for a specific command by...specifying either a long, short or old style option.
一个shell脚本，实现利用OpenSSL生成X509证书 #!...it under the terms of the GNU General Public License as published by the Free Software Foundation; either...version 2 of the License, or (at your option) any later version....-x "$openssl" ] && error "Could not find openssl binary (path=$openssl), please check configuration at...parameters" fi you can either input '*' or 'wildcard' real_cn=$(echo "$1" | sed 's/wildcard/*/g') cn=
一直在网上听说 Tengine 优秀的性能，淘宝自家都使用的 web server，其稳定性和性能已经在淘宝网，天猫商城等得到了很好的检验。...这里就记录一下迁移记录，其实迁移很简单，Tengine基本上继承 Nginx 的所有特性，兼容 Nginx 的配置，所以在迁移上并没花多少时间。...You can either disable the module by using --without-http_rewrite_module option, or install the PCRE.../configure: error: SSL modules require the OpenSSL library....You can either disable the module by using --without-http_gzip_module option, or install the zlib library
在高连接并发的情况下，Nginx是Apache服务器不错的替代品：Nginx在美国是做虚拟主机生意的老板们经常选择的软件平台之一。能够支持高达50,000个并发连接数的响应，而且内存开销极小。.../etc/sysconfig/network # Check that networking is up. [ ${NETWORKING} = "no" ] && exit 0 [ -x $nginxd...$"Usage: $prog {start|stop|restart|reload|status|help}" exit 1 esac exit $RETVAL # chmod u+x...You can either disable the module by using --without-http_rewrite_module option, or install the PCRE...You can either disable the module by using --without-http_gzip_module option, or install the zlib library
_64 x86_64 checking for C compiler ... not found ....You can either disable the module by using --without-http_rewrite_module option, or install the PCRE.../configure: error: the HTTP gzip module requires the zlib library....You can either disable the module by using --without-http_gzip_module option, or install the zlib library.../nginx -s quit 在退出前完成已经接受的连接请求 .
#归档模式， --no-OPTION turn off an implied OPTION (e.g....For the checksum to output for a file, either the --checksum option must be in-effect or the file must...When an option is refused, the daemon prints an error message and exits....Both allow a reference to either a file or a directory....: chdir failed #错误原因：没有在备份服务器上创建/data目录，也就是/etc/rsyncd.conf里面的path = /data/没有创建 rsync error: error
/configure: error: the HTTP rewrite module requires the PCRE library. ...You can either disable the module by using --without-http_rewrite_module option, or install the PCRE...system, or build the PCRE library statically from the source with nginx by using --with-pcre= option...启动 nginx /opt/nginx/sbin/nginx －－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－ 提示： /opt/nginx/sbin/nginx: error....2 (0x00007f549b68e000) /lib64/ld-linux-x86-64.so.2 (0x00007f549c6d2000) ln -s libpcre.so.0.0.1
在该目录下进行编译安装 ; 4 ....You can either disable the module by using --without-http_rewrite_module option, or install the PCRE...You can either disable the module by using --without-http_gzip_module option, or install the zlib library...HTTP 模块配置 : 需要修改 3 个位置 , /path/to/nginx-rtmp-module/ 替换为真实的 nginx-rtmp-module 目录 , 即 /root/rtmp/nginx-rtmp-module...启动 Nginx 服务器 : 需要在 nginx-1.15.3 目录下启动 , 因为要查找 logs/error.log 日志文件 , 只有在该目录下 , 才能按照 logs/error.log 路径查找到该错误日志文件
全系统仿真:在任何受支持的体系结构上为任何计算机运行操作系统 2、用户模式仿真在任何受支持的体系结构上为另一个Linux / BSD目标运行程序 3、虚拟化以接近本机的性能运行KVM和Xen虚拟机 下面介绍在Fedora.../configure make -j6 make install 编译安装出现报错的解决办法 1) ERROR: "cc" either does not exist or does not work.../configure ERROR: "cc" either does not exist or does not work 解决办法 yum install gcc 2)ERROR: glib-2.48...wiki.qemu.org/Documentation/Platforms/ARM 1、图形化问题 virt machine graphics Graphics is also available, but unlike x86...One good option is to use: -device virtio-gpu-pci 2、vnc问题 -display vnc=IP:0
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