Bash

sudo systemctl stop firewalld
sudo systemctl stop ipchains
sudo systemctl stop iptables

sudo systemctl restart jira
sudo systemctl restart atlbitbucket

# clear all
history -c
history -w

# delete line
history -d 2013
history -w

for i in {1..50};do \
history -d 2013;done;\
history -w

count=`wc -l ~/.bash_history|awk '{print $1+1}'`;start_line=$(($count-10));\
for ((line=$count;line>=$start_line;--line));do history -d $line;done;\
history -w

command -v __git_ps1 >/dev/null 2>&1 || { echo >&2 "__git_ps1 not installed";}
hash __git_ps1 >/dev/null 2>&1 || { echo >&2 "__git_ps1 not installed";}
type __git_ps1 >/dev/null 2>&1 || { echo >&2 "__git_ps1 not installed";}

# check by using if else conditional block
if hash __git_ps1 2>/dev/null;then echo '__git_ps1';\
else echo 'no __git_ps1';fi

Bash Arrays

declare -a HADOOP_SCHEDULERS=(dev prod);\
declare -A MINMAX_CAPACITIES=([dev]='50 50' [prod]='50 70');\
for HADOOP_SCHEDULER in ${HADOOP_SCHEDULERS[@]};do \
    for MINMAX_CAPACITY in ${MINMAX_CAPACITIES[${HADOOP_SCHEDULER}]};do \
        echo "${HADOOP_SCHEDULER} => ${MINMAX_CAPACITY}";\
    done;\
done

Knowledge

sudo apt install neofetch
neofetch --cpu-brand off
neofetch

# add the new key(s) to known_hosts
ssh-keyscan -H git.academia.chorke.org >> ~/.ssh/known_hosts

# remove the old key(s) from known_hosts
ssh-keygen -R git.academia.chorke.org

cat /etc/os-release

References

Execute bash script from URL Bash/SQLPlus Input Redirect Bash/Eclipse Workspace Bash Script Structure Bash/Port/Forward Bash/Network Bash/Port Bash/CPU Bash/RAM

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