Shell-alias在Shell脚本中的使用

概述

众所周知，shell脚本使用的是非交互式方式，在非交互式模式下alias扩展功能默认是关闭的，此时虽然可以定义alias别名，但是shell不会将alias别名扩展成对应的命令，而是将alias别名本身当作命令执行，如果shell内置命令和PATH中均没有与alias别名同名的命令，则shell会找不到指定的命令。

在shell中开启alias

使用shell内置命令shopt命令来开启alias扩展选项。shopt是shell的内置命令，可以控制shell功能选项的开启和关闭，从而控制shell的行为

常用命令：

Command	Desc
shopt -s opt_name	Enable (set) opt_name.
shopt -u opt_name	Disable (unset) opt_name.
shopt opt_name	Show current status of opt_name.

比如

查看同义词是否开启（交互模式下）

[/xgj/gj]$shopt expand_aliases
expand_aliases  on

shopt expand_aliases在交互式模式下 默认是打开的，在非交互式模式下是关闭的,但可以用可shopt来将其开启

shopt -s expand_aliases

实际操作

在我们的项目中某个模块的双机启动脚本（root用户下操作），其中应用的启停使用了alias建立的同义词来操作，如果想要在脚本中使用，必须开启同义词才。

项目启动中会依赖一些环境变量，所以双机启动脚本中需要显式的引入.bash_profile文件。

所以我们将 开启alias的命令放在 .bash_profile中。

source .bash_profile 生效。

脚本如下:

#!/bin/bash
##############################################
## Name: drm_script.ps
## Desc: Duplex switch script of DRM 
## Param: None
## Author: Mr Yang
## Date: 2017-07-25
## Version:V1.0
## Comment: /drm/.bash_profile must set "shopt -s expand_aliases" so that the alias in the script works well
##############################################

#atcive the environment variable
source /drm/.bash_profile

#main menu of tomcat and jobserver
tomcat_jobserver_menu=/drm/drm

#main menu of uip and bp1
uip_bp1_menu=/drm/zsmart-uip-8.1.0/bin

#stauts of tomcat(webserver) pgrep -f "\-Dz_app=cvbs" 
status_tomcat=$(pgrep -f Dz_app=cvbs | wc -l)

#status of jobserver
status_jobserver=$(pgrep -f Dz_app=jobserver | wc -l)

#status of uip
status_uip=$(pgrep -f Dz_app=uip | wc -l)

#status of bp1
status_bp1=$(pgrep -f Dz_app=bp1 | wc -l)

#pid of tomcat
pid_tomcat=$(pgrep -f Dz_app=cvbs)

#pid of jobserver
pid_jobserver=$(pgrep -f Dz_app=jobserver)

#pid of uip
pid_uip=$(pgrep -f Dz_app=uip)

#pid of bp1
pid_bp1=$(pgrep -f Dz_app=bp1)


#########################################
#
#start all processes including tomcat/jobserver/uip/bp1 
#start tomcat/jobserver with drmtool 
#start uip/bp1 with uip.sh
#
#########################################
startProcess(){

        echo "stop first"
        #there are some problems if you execute startProcess twice or more times,so stop process first 
        stopProcess


        #start jobserver and tomcat
        echo "begin to start [tomcat,jobserver]"
        su - drm -c "cd $tomcat_jobserver_menu; jobstart ; start; exit" > /dev/null 2>&1

        echo "sleep 5 seconds..."
        sleep 5

        echo "begin to start [uip,bp1]"
        #start uip and bp1
        su - drm -c "cd $uip_bp1_menu; startuip; startbp1; exit" > /dev/null 2>&1
}

#########################################
#
#stop all processes including tomcat/jobserver/uip/bp1 
#stop tomcat/jobserver with drmtool
#stop uip/bp1 with uip.sh
#
#########################################
stopProcess(){
        #stop tomcat、jobserver
        echo "begin to stop process[tomcat,jobserver]"
        su - drm -c "cd $tomcat_jobserver_menu ; stop ; jobstop ; exit" > /dev/null 2>&1
        echo "process[tomcat,jobserver] stopped sucessfully,sleep 3 seconds"
        sleep 3

        #stop uip、bp1
        echo "begin to stop process[uip,bp1]"
        su - drm -c "cd $uip_bp1_menu && stopbp1 && stopuip && exit" > /dev/null 2>&1
        echo process[uip,bp1] stopped sucessfully
}


#########################################
#
#print the status of each process
#
#########################################
status(){
        #status of tomcat
        check_status $status_tomcat  tomcat
        #status of jobserver
        check_status $status_jobserver jobserver 
        #status of uip
        check_status $status_uip uip
        #status of bp1
        check_status $status_bp1 bp1       
}
#########################################
#
#public function
#checking status of each process
#
#########################################
check_status(){
    if [ $1 -eq 1 ] ; then 
            echo "$2 is working..."
    elif [ $1 -gt 1 ] ;then 
            echo -e " \033[31m more than one $2 process has been start,make sure only one process exists \033[0m " 
    else 
            echo -e " \033[31m $2 stopped \033[0m " 
    fi
}

#########################################
#
#stop all processes by force
#find the pid,and kill the pid
#
#########################################
forcedstop(){
        #kill tomcat
    kill_process $pid_tomcat cvbs 
    #kill jobserver
    kill_process $pid_jobserver jobserver
    #kill uip
    kill_process $pid_uip  uip
    #kill bp1
    kill_process $pid_bp1  bp1
}

#########################################
#
#public function
#kill each process
#
#########################################
kill_process(){
    #check the length of $1 [zero:false,non-zero:true] 
    #two parameters [$1->pid,$2->processName],if $1 is null,$2 will replace $1,$2 turns to $1,so make sure $1 is number
    if [[ -n $1 && $1 -gt 0 ]] ; then 
        echo "pid: $1,process: $2"
        kill -9 $1 
            if [ $? == 0 ] ; then 
                echo "pid: $1,process: $2 has been stopped successfully"
                sleep 1
            fi
        else 
            echo -e " \033[31mpgrep -f Dz_app=$1 without result,$1 has been stopped \033[0m " 
    fi
}

#########################################
#
# $1 variable 
# $1 can only with (start/stop/status/restart/forcedstop)
#
#########################################
case "$1" in
   'start')
        startProcess
        ;;
   'stop')
        stopProcess
        ;;
   'status')
        status
        ;;
   'restart')
        #stopProcess
        #sleep 3
        startProcess
        ;;
    'forcedstop')
        forcedstop
        ;;
   *)
        echo -e "\033[31m Usage: $0 { start | stop | restart | forcedstop | status} \033[0m"
        exit 1
esac

exit 0