学步园

网上搜罗而来，验证可用

#! /bin/bash

printf "Enter: "
read var
   if [[ $var =~ ^[0-9]+$ ]]
      then
          echo "Number."
     elif [[ $var =~ ^[A-Za-z]+$ ]]
      then
           echo "String."
     else
           echo "mixed number and string or others "
    fi  

或者 awk or gawk

#! /bin/bash
printf "Enter: "
read var
   echo "$var" | gawk '{
          if ($0 ~ /^[0-9]+$/){
                 print "Number "
          } else if ($0 ~ /^[A-Za-z]+$/){
                 print "String "
          } else {
                 print "Mixed number and string or others"
          }
   }'