002#驗證輸入-僅限字母數字

確保輸入內容僅限於字母和數字

#!/bin/bash
# validAlpNum.sh
# 驗證輸入，僅限字母數字

validAlphaNum() {

  validChar="$(echo $1 | sed -e 's/[^[:alnum:]]//g')"
  if [ "$validChar" = "$1" ]; then
    return 0
  else  
    return 1
  fi
}

echo -n "Enter input: "
read input
if ! validAlphaNum "$input"; then
  echo "Your input must consist of only letters and numbers." >&2
  exit 1
else
  echo "input is valid."
fi

exit 0