ouyi

#/usr/bin/env bash

# Install some pacakages we'll need to compile the driver below.
dnf install gcc kernel-devel -y

# Create working dir for Broadcom driver files and patches.
mkdir hybrid_wl_f23

# Change to working dir.
cd hybrid_wl_f23

ouyi

#!/usr/bin/env bash

for i in {1..9}; do 
    for j in $(seq 1 $i); do 
        echo -n "$j x $i = $( printf '% 2s' $(( $i * $j )))  "
    done
    echo
done

ouyi

#!/usr/bin/env bash

dnf install -y android-tools

# backup apps
adb backup -all -f adb-backup-2017-12-03-v9.adb

# backup photos
adb pull /sdcard/DCIM/Camera/ v9_sdcard_DCIM_Camera/

ouyi

// java 8 test whether a nullable String is empty or not

if (Optional.ofNullable(s).orElse("").isEmpty()) {
    // s is null or empty
}

ouyi

#!/usr/bin/env bash

# docker run -p 14848:4848 -p 18080:8080 -p 18181:8181 --name glassfish oracle/glassfish:5.0
##########GENERATED ADMIN PASSWORD: f621b788  ##########

# docker exec -u 0 -it glassfish bash

ADMIN_PASSWORD=123456
echo "AS_ADMIN_PASSWORD=${ADMIN_PASSWORD}" > /tmp/glassfishpwd

ouyi

# Update commit comments before the push
git commit -m "Fix an issue"
git commit -m "Fix an important issue" --amend

# Throw away all changes on local master and to have it exactly the same as origin/master:
git checkout master
git reset --hard origin/master

# Force origin/master to be the same as local master (dangerous!!!):

ouyi

# [your_project]$ cat .gitattributes
prod/group_vars/vaulted* diff=ansible-vault-prod merge=binary

# [your_project]$ cat ~/.gitconfig
[diff "ansible-vault-prod"]
    textconv = ansible-vault view --vault-password-file ~/vault_prod.txt
...

ouyi

cat >> input.txt
hello
world
world
<ctrl+D>

wget https://raw.githubusercontent.com/ouyi/tez-demo/master/src/test/resources/input.txt
hadoop fs -copyFromLocal input.txt /tmp/

ouyi

top # list processes, shift+p to sort processes by CPU usage
top -H -p <pid> # list threads, shift+p to sort threads by CPU usages
printf "%x\n" <tid> # convert tid to hexadecimal, called nid
jstack -l <pid> | grep -i <nid> -A 15 # get stack trace of the thread

ouyi

image_id="$1"
for i in $(docker images -q); do 
    docker history $i | grep -q "$image_id" && echo $i; 
done | sort -u