This command will clear all the /Library/StageExtensions folder.

# sudo kextcache --clear-staging

only clear some file

# sudo rm -rf /Library/Extensions/somefile

# sudo kextcache -invalidate /

# ls /Library/StagedExtensions/

or

#sudo kextcache  -prune-staging //Prunes the kernel extension staging area by removing all kernel extensions no longer present in their original location.

mkdir build
cd build

cmake -D CMAKE_INSTALL_PREFIX="$Prefix_Dir" 

-D CMAKE_CXX_FLAGS="${CFLAGS} -I/custom/include" 

-D CMAKE_EXE_LINKER_FLAGS="$LDFLAGS"

-DCMAKE_BUILD_TYPE=Debug

-DCMAKE_CXX_COMPILER=g++

xar -xf file.pkg

cat file.pkg/Payload | cpio -i

make -n //dry-run

make SHELL='sh -vx'

检查内核版本

通过uname -r命令检查内核版本是否大于4.9

# uname -r

启用BBR拥塞算法

• 加载内核模块

# modprobe tcp_bbr

# echo "tcp_bbr" >> /etc/modules-load.d/modules.conf

• 修改内核参数

# echo "net.core.default_qdisc=fq" >> /etc/sysctl.conf

very old  https://gist.github.com/mondain/b0ec1cf5f60ae726202e

some fix https://gist.github.com/zziuni/3741933

23.21.150.121:3478

iphone-stun.strato-iphone.de:3478

numb.viagenie.ca:3478

s1.taraba.net:3478

s2.taraba.net:3478

stun.12connect.com:3478

stun.12voip.com:3478

stun.1und1.de:3478

stun.2talk.co.nz:3478

stun.2talk.com:3478

stun.3clogic.com:3478

stun.3cx.com:3478

stun.a-mm.tv:3478

stun.aa.net.uk:3478

stun.acrobits.cz:3478

stun.actionvoip.com:3478

ssh -o ProxyCommand="ssh -W %h:%p root@jump.example.org" root@target.example.org

or write it to ssh config file

Host xxx

HostName target.example.org

User root

IdentityFile ~/.ssh/id_rsa

ProxyCommand ssh -W %h:%p root@jumphost.example.org

another

ssh -L local_Port:target.example.org:22 root@jumphost.example.org

write it to ssh config file using LocalForward

//computer one ip from ifconfig 192.168.1.2  public ip 2.2.2.2  
ip tunnel del ipip0
ip tunnel add ipip0 mode ipip remote 1.1.1.1 local 192.168.1.2
ip addr add 10.0.0.101/24 dev ipip0
ip link set ipip0 up

//computer two ip from ifconfig 192.168.100.2  public ip  1.1.1.1
ip tunnel del ipip0
ip tunnel add ipip0 mode ipip remote 2.2.2.2 local 192.168.100.2
ip addr add 10.0.0.102/24 dev ipip0
ip link set ipip0 up

//iptables

$ git remote add xxx https://xxx.com/xxx.git

# push master to xxx

$ git push xxx master

# Push my-branch to xxx and set it to track xxx/my-branch

$ git push -u xxx my-branch

# Make some existing branch track xxx instead of origin

$ git branch --set-upstream other-branch xxx/other-branch

inherit enable_shared_from_this with public specifier

class a:pubic enable_shared_from_this{}

without pubic,make shared func can not set weak_ptr

so shared_from_this will throw  bad_weak_ptr