(shell)

 ssh_tunnel.sh
 sed_reg_replacement_on_mac.sh
 netcat udp hole punching

curl

for ((i=1; i<=$2; i ++))
do
    curl.exe $1/${i}.jpg -o ${i}.jpg
	echo $i
done
 
for ((i=1; i<=100; i ++))
do
	echo $i
done

for i in {1..100}
do
	echo $i
done

for i in `seq 1 100`
do
	echo $i
done

netcat udp hole punching

locah host
nc -up 22222 jamespond.eicp.net 11111
remote host
nc -lu 11111 -v

send something from local...

remote host
netstat -plan
udp        0      0 104.194.77.241:11111        219.137.141.100:35247       ESTABLISHED 19946/nc

shutdown local nc 
nc -lu 22222
remote host
nc -up 11111 219.137.141.100 35247 

these commands above should run fast or the nat session will be expired soon

sed_reg_replacement_on_mac.sh

    for f in ./*; do
        if [ -f $f ]&&[ `echo $f | grep -c ".js" ` -gt 0 ]; then
            echo `pwd`/$f
            sed -E -i '' "s#\"/(management|service-center)/.*\"#GetAbsUrl(&)#" $f
            sed -E -i '' "s#'/(management|service-center)/.*'#GetAbsUrl(&)#" $f
        fi
    done
    
  ##########
  Page='./build/index.html'
  CSS=`grep -oe '/html/static/css/main.*.css' $Page`
  JS=`grep -oe '/html/static/js/main.*.js' $Page`
  echo $CSS $JS
  sed -E -i '' "s#/html/static/css/main\..*\.css#${CSS}#" ${FTL}/html-head.ftl
  sed -E -i '' "s#/html/static/js/main\..*\.js#${JS}#" ${FTL}/html-foot.ftl

ssh_tunnel.sh

if [[ $(id -u) -ne 0 ]]; then
    echo "Please run as root"
    exit
fi

#echo "docker:1212" | chpasswd
#chmod 0600 ./qy1_rsa

LOCAL=${1:-'12300'}
REMOTE=${2:-'12300'}

while true
do
  echo $(date)" ssh tunnel start..."
  ssh -NT -o ExitOnForwardFailure=yes -o ServerAliveInterval=60 -o ServerAliveCountMax=100 \
    -R *:${REMOTE}:localhost:${LOCAL} git@121.201.24.170 -i ./qy1_rsa
  sleep 30
done

How to make ssh tunnel open to public?
GatewayPorts=clientspecified or GatewayPorts clientspecified
In order to use that, you probably need to add "GatewayPorts yes" to your server's /etc/ssh/sshd_config

In case you want a hard link ln to a directory...

mount -t bind /var/www /home/user/workspace/www
This is very dangerous because most tools and programs will not be aware of the binding. I once did something like in the above example and then proceeded to rm -rf /home/user. Luckily, there was nothing relevant in /var/www.

find some file larger than

find . -type f -size +4096c
to find files bigger than 4096 bytes.

And :

find . -type f -size -4096c
to find files smaller than 4096 bytes.

Notice the + and - difference after the size switch.

The -size switch explained:

-size n[cwbkMG]

File uses n units of space. The following suffixes can be used:

`b'    for 512-byte blocks (this is the default if no suffix  is
                            used)

`c'    for bytes

`w'    for two-byte words

`k'    for Kilobytes       (units of 1024 bytes)

`M'    for Megabytes    (units of 1048576 bytes)

`G'    for Gigabytes (units of 1073741824 bytes)

The size does not count indirect blocks, but it does count
blocks in sparse files that are not actually allocated. Bear in
mind that the `%k' and `%b' format specifiers of -printf handle
sparse files differently. The `b' suffix always denotes
512-byte blocks and never 1 Kilobyte blocks, which is different
to the behaviour of -ls.