检查bash脚本中的用户输入错误 [英] Check user input for errors in bash script

问题描述

请看下面的代码：

  echo "nhat and betah for each element 
        TIPS: 4 REAL NUMBER for each element(eg, 1.0 0.0 1.0 .1)"
  read -a nbh
  if [ ${#nbh[@]} -ne 4 ]
  then 
    echo "Wrong!! "
  fi

此错误检查（if循环）将终止该程序，如果我忘了给出4个元素。
有可能，而不是终止，给用户一次机会（又一次）？即基本上再次转到读-a nbh 行？

This error check (if loop) will terminate the program, if I forget to give exactly 4 elements. Is it possible, rather then terminating, give the user a chance again (and again)? i.e. basically go to the read -a nbh line again?

推荐答案

一个而这个条件不匹配可以使它：

#!/bin/bash

while [ ${#nbh[@]} -ne 4 ] <---- repeat until this is not true
do
  echo "nhat and betah for each element 
        TIPS: 4 REAL NUMBER for each element(eg, 1.0 0.0 1.0 .1)"
  read -a nbh
  if [ ${#nbh[@]} -ne 4 ]
  then 
    echo "Wrong!! "
  fi
done                       <---- finish while loop

测试

Test

$ ./script
nhat and betah for each element 
        TIPS: 4 REAL NUMBER for each element(eg, 1.0 0.0 1.0 .1)
2 3
Wrong!! 
nhat and betah for each element 
        TIPS: 4 REAL NUMBER for each element(eg, 1.0 0.0 1.0 .1)
2 3 5 6
$

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