test for a specific port from Linux or Unix command line https://www.cyberciti.biz/faq/ping-test-a-specific-port-of-machine-ip-address-using-linux-unix/ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 # check for tcp port ## ## need bash shell echo >/dev/tcp/{host}/{port} (echo >/dev/tcp/{host}/{port}) &>/dev/null && echo "open" || echo "close" (echo >/dev/udp/{host}/{port}) &>/dev/null && echo "open" || echo "close" (echo >/dev/tcp/www.cyberciti.biz/22) &>/dev/null && echo "Open 22" || echo "Close 22" (echo >/dev/tcp/www.

PD 充电协议 thinkpad的 PD 充电协议有可能和通用的 协议 不同, 某些情况下不能握手充电. 紫米65W充电器使用了USB PD中的PPS规范，而部分

raspberry pi docker 1 curl -sSL https://get.docker.com | sh https://www.raspberrypi.org/blog/docker-comes-to-raspberry-pi/

helm Helm 是 Kubernetes 的包管理器 1 2 3 4 5 6 7 # archlinux pacman -S helm # curl curl -fsSL -o get_helm.sh https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 chmod 700 get_helm.sh ./get_helm.sh

iptables nat 1 2 iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE iptables -t nat -A POSTROUTING -s 10.10.10.0/24 -o eth0 -j MASQUERADE nat 表需要的三个链: PREROUTING:可以在这里定义进行目的NAT的规则,因为路由器进行路

the log http://www.cnblogs.com/foreach-break/p/notes_about_distributed_system_and_The_log.html Log是如下系统的核心: 分布式图数据库 分布式搜索引擎 Hadoop 第一代和第二代K-V数据库 Log可能跟计算机的历史一样长,并且是分布式数据系统和

protocol buffers, protobuf install protoc 1 2 3 4 5 6 # archlinux 可以从仓库直接安装 pacman -S protobuf # 其它发行版, 比如 ubuntu 可以下载二进制包 解压即可. https://github.com/protocolbuffers/protobuf/releases/download/v3.6.1/protoc-3.6.1-linux-x86_64.zip # set protoc to PATH protoc -help windows download protoc https://developers.google.com/protocol-buffers/docs/downloads define message format in a .proto file 1 2 3

consumer group https://www.cnblogs.com/huxi2b/p/6223228.html

java 纳秒 http://hold-on.iteye.com/blog/1943436 前段时间项目中需要 统计接口连接时间,考虑到连接时间一般都是零点几毫秒级别的,为了拿到更精确地数值,没有使用System.curren

Base64 base64是一种将二进制的01序列转化成ASCII字符的编码方法。编码后的文本或者二进制消息, 就可以运用SMTP等只支持ASCII字符的

redis string Redis 字符串数据类型的相关命令用于管理 redis 字符串值 template 1 2 3 4 5 6 7 8 9 SET key value [EX seconds] [PX milliseconds] [NX|XX] EX、PX、NX、XX 是 redis 2.6.12 版本添加的可选参数 EX second: 设置键

chrome os, chromeos basic chrome os 多桌面 https://support.google.com/chromebook/answer/9594869?hl=en Drag windows and apps to your preferred desk. Or use shortcuts: Move a window to a new desk: Right-click the top of a window then, select Move window to another desk. Make a window or app available across all desks: Right-click the top of a window, then select Show in all desks. crosh Crosh stands for “Chr

easy-rsa 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 #debian apt-get install easy-rsa mkdir /etc/openvpn cp -r /usr/share/easy-rsa /etc/openvpn/ cd /etc/easy-rsa vim vars ./clean-all ./build-ca ./build-key-server server0 ./build-key client0 #--- pacman -S easy-rsa cd /etc/easy-rsa export EASYRSA=$(pwd) easyrsa init-pki easyrsa build-ca scp /etc/easy-rsa/pki/ca.crt foo@hostname-of-openvpn-server:/tmp/ca.crt #OpenVPN server machine mv /tmp/ca.crt /etc/openvpn/server/ chown root:root /etc/openvpn/server/ca.

OpenVPN 使用账号+密码方式登陆 http://openwrt.iteye.com/blog/2306421 https://xu3352.github.io/linux/2017/06/08/openvpn-use-username-and-password-authentication OpenVPN 使用账号+密码方式登陆 使用账号+密码方式方便给多人分配不同的账号和密码,多人使用更加方便 原文链接: 配置Open

openvpn 开放端口 Network> Firewall> Traffic Rules> Open ports on router 以80端口为例: Name: Allow HTTP (这个名字可以随便填) Protocal: TCP External port: 80 然后点击 Save & Apply ,就可以访问了 http://www.anywlan.com/thread-432580-1-1.html

Trusting additional CAs in Centos place the certificate to be trusted (in PEM format) in /etc/pki/ca-trust/source/anchors/ 1 2 3 cp xxx.pem /etc/pki/ca-trust/source/anchors/ update-ca-trust enable sudo update-ca-trust

openwrt install build R7800, Build custom Netgear R7800 firmware for a larger flash size/root space http://blog.wiloon.com/?p=12113&embed=true#?secret=Z4x4I19l6b burn netgear 刷机, factory.img, sysupgrade.bin http://blog.wiloon.com/?p=12826&embed=true#?secret=G3qiDnmUJx 改网段 openwrt lan 改网段 http://blog.wiloon.com/?p=12761&embed=true#?secret=XiBcmLWKRM openvpn https://openwrt.org/docs/guide-user/services/vpn/openvpn/basic enable https for wget opkg install librt openssl-util opkg install wget ca-certificates

‘netgear 刷机, factory.img, sysupgrade.bin, openwrt’ xxx-factory.img 把网线连接路由器的 LAN 口 和 PC 的网口 路由器断电, 用牙签或其他工具, 捅路由器的 reset 口 开启设备电源开关, 观察电源灯 (此时保持按住 reset/ Restore Factory

kvm http://blog.51cto.com/changfei/1672147 KVM-Qemu-Libvirt 三者之间的关系 Qemu Qemu是一个模拟器,它向Guest OS模拟CPU和其他硬件, Guest OS认为自己和硬件直接打交道,其实是同Qemu模拟出来

google 搜索 转义, 加引号 1 linux "-xxx" 特定域 1 2 site: 在特定域中进行搜索 -site: 排除特定域 文件类型 1 filetype: PDF