【linux实战3】测试工程师实战课程之三剑客实战抽奖程序脚本

抽奖基本原理

seeds=`cat wx.txt`
seeds=`for seed in $seeds;do (($RANDOM%2==0)) && echo $seed;  done`

a && b

  • 如果a或者b有一个是false,那么结果就是false
  • 如果a或者b都是true,那么结果就是true

true && b
false && b :短路

vim

vim ~/.vimrc 
set nu

抽奖实现1:有空白

#!/bin/bash
rand() {
  #bug 1
  seeds=`while read line; do echo ${line// /..}; done < wx.txt`
  while [[ $count != 1 ]];do
    seeds=`for seed in $seeds;do (($RANDOM%2==0)) && echo $seed;  done`
    count=`echo "$seeds" | wc -l`
  done
  #bug3
  echo $seeds
}

rand

抽奖实现2:无空白

#!/bin/bash
rand() {
  local count
  local seeds
  count=0
  seeds=`while read line; do echo ${line// /..}; done < wx.txt`
  while [[ $count != 1 ]];do
    seeds=`for seed in $seeds;do (($RANDOM%2==0)) && echo $seed;  done`
    count=`echo "$seeds" | wc -l`
  done
  if [[ $seeds == "" ]];then
    rand
  fi  
  if [[ $seeds != "" ]];then
    echo $seeds
  fi  
}

抽奖实现3:去重

此处代码跟课上不一样,课上的代码在is_repeat函数有一些错误!!跟同学们说声抱歉,是我失误了

rand() {
  local seeds
  local count
  count=0
  seeds=`while read line;do echo ${line// /..}; done<test.txt`
  while [[ $count != 1 ]];do
    seeds=`for seed in $seeds;do (($RANDOM%2==0)) && echo $seed;done`
    count=`echo "$seeds" | wc -l`
  done
  if [[ $seeds == "" ]];then
    rand
  fi
  if [[ $seeds != "" ]];then
   echo $seeds 
  fi
  
}

res() {
 for i in `eval echo {1..$1}`;do
  tmp=`rand`
   while [[ `is_repeat $tmp` == 0  ]];do
     tmp=`rand`
   done
   arrs[$i]=$tmp
 done
 echo ${arrs[@]}
}

is_repeat() {
  for arr in ${arrs[@]};do
    if [[ $arr == $1  ]];then
      #此处需要有echo,因为子进程只能捕获echo的输出,不能捕获return的值
      echo 0
      return 0
    fi
  done
#输出1的逻辑在这里,因为需要遍历完整的数组后,才能输出1
  echo 1
}
res $1

抽象实现4:参数化

res() {
 for((i=0;i<$1;i++));do
   tmp=`rand`
   while [[ `is_repeat $tmp` ]];do
    tmp=`rand`
   done
   arrs[$i]=$tmp
 done
 echo ${arrs[@]}
}
res $1

结果

  1. 通通 :5
  2. 平庸与浩荡:10
  3. 安灵:15
  4. 沨晴: 20
  5. 唐嘻嘻: 25
  6. 提摩太: 30
1 Like

image

还有两个个问题:
1、for循环、或者是其他的循环里,如果有return语句是不是就直接跳出循环了
2、func 和 [[ func ]]有什么区别,都是返回函数返回值吗?

@yuruotong1

代码的确有问题,我已经更新了

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