统计进程内存使用量

#!/bin/bash

# 文件名: show_memory.sh
# 作者: wanghongwei
# 日期: 2024年9月29日
# 版本: 1.0
# 描述: 统计进程内存使用量
# 使用方式: ./show_memory.sh [-k/-K] [-m/-M] [-g/-G]

# 初始化所有进程的统计变量
declare -A TOTAL_MEM_SIZE
TOTAL_MEM_SIZE[KB]=0

Usage() {
	echo "提示：请指定您想要显示的单位"
	echo "Usage: $0 [-k/-K] [-m/-M] [-g/-G]"
	exit 1
}

Title() {
	echo "+----------+----------------------+"
	printf "| %-8s | %-20s |\n" "PID" "Total Memory ($1)"
	echo "+----------+----------------------+"
}

ShowMemory() {
	for PID in /proc/[0-9]*; do
		PID=${PID##*/}

		# 初始化单个进程的统计变量
		declare -A PROCESS_MEM_TOTAL
		PROCESS_MEM_TOTAL[KB]=0

		# 获取进程的内存信息
		PROCESS_MEM_INFO=$(cat /proc/${PID}/smaps 2>/dev/null | grep -v " 0 kB" | grep "Rss")

		while read line; do
			if [[ $line =~ ^Rss:[[:space:]]+([0-9]+) ]]; then
				PAGE_SIZE=${BASH_REMATCH[1]} # BASH_REMATCH[1] 包含第一个括号中匹配的内容
				PROCESS_MEM_TOTAL[KB]=$((PROCESS_MEM_TOTAL[KB] + PAGE_SIZE))
			fi
		done <<<"$PROCESS_MEM_INFO"

		# 累加全局统计
		TOTAL_MEM_SIZE[KB]=$((TOTAL_MEM_SIZE[KB] + PROCESS_MEM_TOTAL[KB]))

		# 单位换算
		case "$1" in
		"KB") : ;;
		"MB") PROCESS_MEM_TOTAL[MB]=$(echo "scale=3; ${PROCESS_MEM_TOTAL[KB]} / 1024" | bc) ;;
		"GB") PROCESS_MEM_TOTAL[GB]=$(echo "scale=6; ${PROCESS_MEM_TOTAL[KB]} / 1024 / 1024" | bc) ;;
		*) : ;;
		esac

		# 打印单个进程的内存统计
		if [[ ${PROCESS_MEM_TOTAL[KB]} -gt 0 ]]; then
			printf "| %-8s | %-20s |\n" "${PID}" "${PROCESS_MEM_TOTAL[$1]} $1"
		fi
	done
}

Summary() {
	# 单位换算
	case "$1" in
	"KB") : ;;
	"MB") TOTAL_MEM_SIZE[MB]=$(echo "scale=3; ${TOTAL_MEM_SIZE[KB]} / 1024" | bc) ;;
	"GB") TOTAL_MEM_SIZE[GB]=$(echo "scale=6; ${TOTAL_MEM_SIZE[KB]} / 1024 / 1024" | bc) ;;
	*) : ;;
	esac

	# 打印总统计
	echo "+----------+----------------------+"
	printf "| %-8s | %-20s |\n" "Total:" "${TOTAL_MEM_SIZE[$1]} $1"
	echo "+----------+----------------------+"
}

main() {
	if [ -z "$1" ]; then
		Usage
	fi

	case "$1" in
	-k | -K)
		Title KB
		ShowMemory KB
		Summary KB
		;;
	-m | -M)
		Title MB
		ShowMemory MB
		Summary MB
		;;
	-g | -G)
		Title GB
		ShowMemory GB
		Summary GB
		;;
	*) Usage ;;
	esac
	exit 0
}

main $1