如何使用 Shell 脚本检查用户输入值是大写、小写还是数字？

Question

我正在尝试编写shell script来读取用户输入数据并检查输入值是大写、小写还是其他。 但我写的只是检查一个字符

这是我写的：

printf 'Please enter a character: '
IFS= read -r c
case $c in
  ([[:lower:]]) echo lowercase letter;;
  ([[:upper:]]) echo uppercase letter;;
  ([[:alpha:]]) echo neither lower nor uppercase letter;;
  ([[:digit:]]) echo decimal digit;;
  (?) echo any other single character;;
  ("") echo nothing;;
  (*) echo anything else;;
esac

如何让它读取一个长字符串而不是单个字符并相应地获取 output？

Answer 1

您可以通过多种方式做到这一点，这里有一种：

#!/bin/bash

read -p "Enter something: "  str
echo "Your input is: $str"

strUppercase=$(printf '%s\n' "$str" | awk '{ print toupper($0) }')
strLowercase=$(printf '%s\n' "$str" | awk '{ print tolower($0) }')

if [ -z "${str//[0-9]}" ]
then
    echo "Digit"
elif [ $str == $strLowercase ]
then
    echo "Lowercase"
elif [ $str == $strUppercase ]
then
    echo "Uppercase"
else
    echo "Something else"
fi

Answer 2

在使用shopt -s extglob ，您可以使用+([[:upper:]])来匹配由一个或多个大写字母组成的字符串。

来自man 1 bash ：

       If the extglob shell option is enabled using the shopt builtin, several
       extended  pattern  matching operators are recognized.  In the following
       description, a pattern-list is a list of one or more patterns separated
       by a |.  Composite patterns may be formed using one or more of the fol‐
       lowing sub-patterns:

              ?(pattern-list)
                     Matches zero or one occurrence of the given patterns
              *(pattern-list)
                     Matches zero or more occurrences of the given patterns
              +(pattern-list)
                     Matches one or more occurrences of the given patterns
              @(pattern-list)
                     Matches one of the given patterns
              !(pattern-list)
                     Matches anything except one of the given patterns

例如，使用+([[:upper:][:digit:].])来匹配一个或多个{大写字母、数字、空格、点}。 考虑使用POSIX 标准中定义的以下其他一些类：
alnum alpha ascii blank cntrl digit graph lower print xdigit space upper word punct

证明（只是对示例的测试）它有效：

shopt -s extglob; case "1A5. .Q7." in (+([[:upper:][:digit:] .])) echo "it works";; esac