〖Linux〗以后台方式启动/结束指定程序/命令（不受 exit 或点击窗口关闭按钮等终端退出操作的影响）

#!/bin/bash -
#===============================================================================
#
#          FILE: bgcmd
#
#         USAGE: 方式1 -- $ ./bgcmd             # 启动指定后台程序
#                方式2 -- $ ./bgcmd off         # 结束指定后台程序
#
#   DESCRIPTION: 后台运行程序/命令（类似于deamon进程）
#
#       OPTIONS: ---
#  REQUIREMENTS: >> 按需要修改 cmd 和 need_root 这两个变量<<
#          BUGS: ---
#         NOTES: ---
#        AUTHOR: linkscue(scue),
#  ORGANIZATION:
#       CREATED: 2013年08月14日 22时04分38秒 HKT
#      REVISION:  ---
#===============================================================================

get_process(){
cmd="$1"
ps aux | grep -v 'grep' | grep "$cmd" | awk '{print $2}'
}

kill_process(){
exist="$1"
if [[ "$need_root" != "" ]]; then
sudo kill $exist
else
kill $exist
fi
echo "process [ $(echo $exist) ] had killed."
}

#-------------------------------------------------------------------------------
#  cmd: 希望在后台执行的程序/命令
#  need_root: 是否需要root权限执行
#-------------------------------------------------------------------------------
need_root=true
cmd="python -m SimpleHTTPSever 80"

# get root, if need.
if [[ "$need_root" != "" ]]; then
sudo ls > /dev/null
ret=$?
if [[ $ret != 0 ]]; then
echo "can't get root, exit."
exit 1
fi
fi

# run cmd
exist=$(get_process "$cmd")
if [[ "$1" != "" ]] ; then                      # kill process
kill_process "$exist"
else
if [[ "$exist" != "" ]]; then
kill_process "$exist"
fi
if [[ "$need_root" != "" ]]; then
sudo nohup $cmd >/dev/null 2>&1 &       # run as root
else
nohup $cmd > /dev/null 2>&1 &           # run as other
fi
sleep 0.1
exist=$(get_process "$cmd")
echo "run [ $(echo $exist) ] at background."
fi