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 -ax HADOOP_SCHEDULERS=(dev prod);\
declare -Ax MINMAX_CAPACITIES=([dev]='50 50' [prod]='50 70');\
for HADOOP_SCHEDULER in ${HADOOP_SCHEDULERS[@]};do \
IFS=' ' read -r -a MINMAX_CAPACITY <<< "${MINMAX_CAPACITIES[${HADOOP_SCHEDULER}]}";\
    echo "${HADOOP_SCHEDULER} » Min » ${MINMAX_CAPACITY[0]} » Max » ${MINMAX_CAPACITY[1]}";\
done

Date Format

echo "$(date '+%d/%m/%Y %H:%M:%S [%:z %Z]')" echo "$(date '+%Y-%m-%d-T%Hh%Mm%Ss-MYT')" echo "$(date '+%Y-%m-%d-T-%H-%M-%S-MYT')"	echo "$(date '+%Y-%m-%d-%HH%M-%S-MYT')" echo "$(date '+%Y-%m-%d-%HH%MM%S-MYT')" echo "$(date '+%Y-%m-%dT%H:%M:%SMYT')"	echo "$(date '+%Y-%m-%d-T%H%M%S-MYT')" echo "$(date '+D%Y%m%d-T%H%M%S-MYT')" echo "$(date '+%Y%m%d-T%H%M%S-MYT')"
echo "$(date '+%Y%m%dT%H%M%SMYT')" echo "$(date '+%F-%kh%M')"

Lines Match Between

BASH_REMOTE_SCRIPT_FRMT=$(cat <<'EOF'
# suppress stdout
echo '/* $STDOUT$'
echo "${HOSTNAME}${HOME}"

ssh -qt gtw.vpc.chorke.org <<'EOF_00'
echo "${HOSTNAME}${HOME}"
ssh -qt app.vpc.chorke.org <<'EOF_01'
echo "${HOSTNAME}${HOME}"
echo '$STDOUT$ */'

pg_dump postgres://academia:%[email protected]:5432/%s
# suppress stdout
echo '/* $STDOUT$'
EOF_01
EOF_00
echo '$STDOUT$ */'
EOF
)

---

BASH_REMOTE_SCRIPT_PASS='sadaqah!'
BASH_REMOTE_SCRIPT_PGDB='academia_keycloak_staging'
printf -v  BASH_REMOTE_SCRIPT_EXEC          "${BASH_REMOTE_SCRIPT_FRMT}" "${BASH_REMOTE_SCRIPT_PASS}" "${BASH_REMOTE_SCRIPT_PGDB}"
printf -v  BASH_EXPORT_SCRIPT_DUMP '%s.sql' "${BASH_REMOTE_SCRIPT_PGDB}"
bash -c "${BASH_REMOTE_SCRIPT_EXEC}" >       ${BASH_EXPORT_SCRIPT_DUMP}

---

sed '/^\/\* \$STDOUT\$$/,/^\$STDOUT\$ \*\/$/{/^\/\* \$STDOUT\$$/!{/^\$STDOUT\$ \*\/$/!d}}' -i ${BASH_EXPORT_SCRIPT_DUMP}
sed -z 's|\n/\* $STDOUT$\n$STDOUT$ \*/||g' -i ${BASH_EXPORT_SCRIPT_DUMP}
sed -z 's|/\* $STDOUT$\n$STDOUT$ \*/\n||g' -i ${BASH_EXPORT_SCRIPT_DUMP}
gzip ${BASH_EXPORT_SCRIPT_DUMP}

Package Status

TMUX_INSTALL_STATUS="$(dpkg-query -W --showformat='${db:Status-Status}' 'tmux' 2>&1)"
if [[ ! $? -eq 0 ]]||[[ ! "${TMUX_INSTALL_STATUS}" -eq 'installed' ]];then
    printf 'tmux \033[0;31mnot found! \033[0m:(\n';exit 1
fi

POWERLINE_INSTALL_STATUS="$(dpkg-query -W --showformat='${db:Status-Status}' 'powerline' 2>&1)"
if [[ ! $? -eq 0 ]]||[[ ! "${POWERLINE_INSTALL_STATUS}" -eq 'installed' ]];then
    printf 'powerline \033[0;31mnot found! \033[0m:(\n';exit 1
fi

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

Bash read a properties file contains keys & values What does set -e and set -a do in bash Bash split a string using delimiter Difference between sh & bash Bash Arrays, version 4 Use Bash Arrays PostgreSQL Sendmail JQ Tool

sed » Delete All Lines between two match Check if a package is installed or not Meaning of -x Inside If Condition sed » Multi-line Pattern Match Keep Associative Array Order Other Comparison Operators File Test Operators TMux