这个shell脚本可以使用shell的关联数组对

#!/bin/bash#command to execute script: su - postgres -c "./create.sh"#default value refer to standard server(cpu:6cores,memory:32G,storage:12T)#value according to the actual situation  #List of parameters to be modified:<<!	enable_seqscan = off	enable_indexscan = on	enable_bitmapscan = on	max_connections = 1000	shared_buffers = 16GB	effective_cache_size = 24GB	work_mem = 32MB	temp_buffers = 32MB	wal_buffers = 512MB	maintenance_work_mem = 2GB	autovacuum_max_workers = 3	autovacuum_work_mem = 256MB	checkpoint_timeout = 30min	max_wal_size = 4GB	min_wal_size = 1GB	checkpoint_completion_target = 0.9	log_destination = csvlog	log_directory = pg_log	logging_collector = on	log_min_duration_statement = 800	log_rotation_size = 1024MB	log_truncate_on_rotation = on	log_filename = 'xl_log_%a.log'! ERROR="\033[41;37m ERROR \033[0m"INFO="\033[42;37m INFO \033[0m"WARN="\033[43;37m WARN \033[0m"COMMON_ERROR="some error happened, specific information please see console output" # Array of parametersdeclare -A parameter_arrayparameter_array=([enable_seqscan]=off [enable_indexscan]=on [enable_bitmapscan]=on [max_connections]=1000 [shared_buffers]=16GB [effective_cache_size]=24GB [work_mem]=32MB [temp_buffers]=32MB [wal_buffers]=512MB [maintenance_work_mem]=2GB [autovacuum_max_workers]=3 [autovacuum_work_mem]=256MB [checkpoint_timeout]=30min [max_wal_size]=4GB [min_wal_size]=1GB [checkpoint_completion_target]=0.9 [log_destination]=csvlog [log_directory]=pg_log [logging_collector]=on [log_min_duration_statement]=800 [log_rotation_size]=1024MB [log_truncate_on_rotation]=on [log_filename]=viid_log_%a.log ) #default value :pgctl_path=data_directory=memory= # check command exit value, 0 is successfunction check_fun(){	status=$?	error=${COMMON_ERROR}	if [[ 0 -ne ${status} ]] ; then		echo -e "${ERROR} ${error}"		exit 1	fi} # prepare conditionsfunction prepare_conditions(){	data_directory=$(psql -qtAX  -c "show data_directory" | sed 's/[ ]//g')	check_fun	if [[ ! -d "${data_directory}" ]] ; then		echo -e "${ERROR} database's data directory does not exist"		exit 1	fi	# physical machine environment	memory=$(grep MemTotal /proc/meminfo | awk '{print $2 / 1024 / 1024}' | sed 's/\.[0-9]*//' | tail -n 1)	check_fun	# docker environment 	memory_limit=$(($(awk '{print $1}' /sys/fs/cgroup/memory/memory.limit_in_bytes) / 1024 / 1024 /1024))	check_fun	# comparing the two, choose the smaller one.	if [[ "${memory_limit}" -le "${memory}" ]] ; then		memory=${memory_limit}	fi} # calculate parametersfunction calculate_parameters(){	# 50%*memory	parameter_array[shared_buffers]=$((memory * 1024 / 2))"MB"	# 75%*memory	parameter_array[effective_cache_size]=$((memory * 1024 * 3 / 4 ))"MB"	# <1%	parameter_array[work_mem]=${memory}"MB"	# <1%	parameter_array[temp_buffers]=${memory}"MB"	# 32GB => 512MB	parameter_array[wal_buffers]=$((memory * 16 ))"MB"	# 32GB => 2048MB	parameter_array[maintenance_work_mem]=$((memory * 64 ))"MB"} # modify parametersfunction modify_parameters(){	# modify parameters by modifying file postgresql.conf:	for parameter in ${!parameter_array[*]}	do		#check whether the parameters have been modified		# PostgreSQL's default parameter configuration example: enable_seqscan = on		# viid's example: enable_seqscan='on'		check_out=$(grep "^${parameter}=" "${data_directory}"/postgresql.conf | grep -v '#' | tail -n 1)		# process sleep 		sleep 0.2s		if [[ -z "${check_out}" ]] ; then			echo "${parameter}='${parameter_array[${parameter}]}'" >> "${data_directory}"/postgresql.conf			check_fun			echo -e "${INFO} modify ${parameter} successfully"		else 			if [[ "${check_out}" = "${parameter}='${parameter_array[${parameter}]}'" ]] ; then				echo -e "${INFO} ${parameter} is already configured, then skip this step"			else				sed -i s!^"${check_out}"!"${parameter}='${parameter_array[${parameter}]}'"!g  "${data_directory}"/postgresql.conf				check_fun				echo -e "${INFO} modify ${parameter} successfully"			fi		fi	done} # create directory(pg_log and pg_arch), and set user postgres permissionfunction create_dir(){	directory_array=("pg_arch" "pg_log")	for directory in ${directory_array[*]};	do		# process sleep 		sleep 0.2s		if [[ ! -d "${data_directory}/${directory}" ]] ; then			mkdir -p "${data_directory}"/"${directory}"			echo -e "${INFO} path ${data_directory}/${directory} create successfully"		else 			echo -e "${INFO} ${data_directory}/${directory} is already exists, then skip this step"		fi	# set user postgres permission	chown postgres:postgres "${data_directory}"/"${directory}"	done} # because the environment is different, need to find the path of the database restart command 'pg_ctl'function find_cmd(){	result=$(find / -name pg_ctl 2> /dev/null | grep bin/pg_ctl$ | tail -n 1 )	# check whether the path exists	if [[ -z "${result}" ]] ; then		echo -e "${ERROR} database restart command 'pg_ctl' not exists"		echo -e "${ERROR} please check to see if the database is installed or the command directory does not have permission to access it"		exit 1	else 		echo -e "${INFO} database restart command 'pg_ctl' path: ${result}"		pgctl_path=${result}	fi} # user choose whether to restart or notfunction check_restart(){	read -r -p "Is it necessary to restart database immediately?[Enter YES or NO]:" result	if [[ "${result,,}" = "yes" ]] ; then		echo -e "${INFO} start to restart database"		${pgctl_path} restart -D "${data_directory}" >& /dev/null		if [[ 0 -ne ${status} ]] ; then			echo -e "${ERROR} restart database failed"			exit 12		fi	elif [[ "${result,,}" = "no" ]] ; then		echo -e "${WARN} please restart database manually"		echo -e "${WARN} if you don't restart, database may not be available"		exit 11	else		echo -e "${ERROR} invalid input,please enter again"		check_restart	fi} # ******* start *******# prepare conditions:memory ,data_directoryprepare_conditions# calculate parameterscalculate_parameters# modify parametersmodify_parameters # create directory(pg_log and pg_arch)create_dir# the path of the database restart command 'pg_ctl'find_cmd# remind user that they need to restart database to take effect# process sleep sleep 0.5secho -e ""echo -e "*******************************************************************"echo -e "*                                                                 *"echo -e "*                                                                 *"echo -e "*                restart database to take effect                  *"echo -e "*                                                                 *"echo -e "*                                                                 *"echo -e "*******************************************************************"# process sleep sleep 0.5s# user choose whether to restart or not # check_restartecho -e "${INFO} start to restart database"${pgctl_path} restart -D "${data_directory}" >& /dev/null 
复制