# 获取当前日期
now=`date +"%d_%m_%y"`
# 构建文件名
file=transaction${now}.dat.gz
# 将头部字段逐行存入header_fieldc变量
header_fieldc=`zcat $file | head -1 | tr "|" "\n"`
# 将header_fieldc拆分为数组a
a=( $header_fieldc )
# 使用循环遍历每个字段
for (( i=0; i<=${#a[@]}; i++ ));do
  echo "${a[i]}"
  
  # 对于第一个字段特殊处理
  if [ $i == 0 ];then
    i=`expr $i + 1 `
    # 从文件中提取第i个字段的记录
    rec_fieldc=`zcat $file | sed '1d;$d' | cut -d\| -f $i `
  fi
  
  # 将rec_fieldc字段拆分为数组b
  b=( $rec_fieldc )
  # 使用循环遍历记录中的每个元素
  for (( j=0; j<=${#b[@]}; j++ ));do
    echo "${b[j]}"
    var=`echo "${b[j]}" `
    # 检查元素是否为整数
    if [[ "${var}" =~ ^[0-9]+$ ]];then
      echo " ${b[j]} 是有效的记录"
    else
      echo "${a[j]} 字段中存在无效字符" > exception.txt
      exit 0
    fi
  done
done

**注意：不要忘记，if语句使用 `==` 来比较，而不是 `=`，否则我认为您的代码可能会在此方面工作，如果您更正了这个错误。**
我复制了设置，如下所示。我添加了一些具有更多/更少字段的行以进行演示。sample_data.txt的内容：
```plaintext
Header | <Transaction ID> | <Item Name> |<Item Type> | <Customer ID> | <Type of Transaction> | <Payment Method>| Amount
Data |1001 |Samsung |Handset |R2R003 |Online |Credit Card |100|
Data |1001 |Samsung |Handset |R2R003 |Online |extra |Credit Card |100|
Data |1001 |Samsung |Online |Credit Card |100|
Data | 1004|LG |TV | R2R042| Online | Debit card|150.24|
Data |1001 |Samsung |Handset |R2R003 |Online |extra |Credit Card |100|
Trailer | 2

#!/bin/bash
header_field_count=$(cat sample_data.txt | awk -F '|' '{print NF}' |head -1)
echo 'header_field_count:' $header_field_count
number_of_lines=$(wc -l < sample_data.txt)
echo 'number of lines to process in file:' $number_of_lines
let current_line=2 #跳过第一行，因为那是标题
data_field_count_array=($(cat sample_data.txt | awk -F '|' '{print NF -1}')) # 注意NF -1，因为这些行末尾有一个额外的分隔符
while [ $current_line -lt $number_of_lines ]; do
  echo 'line:' $current_line 'has' ${data_field_count_array[$current_line-1]} 'fields' #bash数组从零开始索引，因此要减1（第1行的索引为0）
  if [[ ${data_field_count_array[$current_line-1]} == $header_field_count ]]; then
    echo 'EQUAL to the Header'
  else
    echo 'NOT EQUAL to the Header'
  fi
  let current_line+=1
done
# 这将打印样本数据中的任何重复行
echo -n 'duplicate lines: '
echo $(sort sample_data.txt  | uniq -d)

header_field_count: 8
number of lines to process in file: 6
line: 2 has 8 fields
EQUAL to the Header
line: 3 has 9 fields
NOT EQUAL to the Header
line: 4 has 6 fields
NOT EQUAL to the Header
line: 5 has 8 fields
EQUAL to the Header
duplicate lines: Data |1001 |Samsung |Handset |R2R003 |Online |extra |Credit Card |100|

#!/bin/bash
#正则表达式示例
echo 'testing string:"'$@'"'
re='^[0-9 -.]'     #数字、数字和负数或小数点允许
if ! [[ $@ =~ $re ]]; then #将输入与允许的字符正则表达式进行比较
  echo 'not a decimal or negative number'
fi
re='^[a-z ,]'     #允许小写字母和空格逗号
if ! [[ $@ =~ $re ]]; then
  echo 'not a lowercase string with SPACE or COMA'
fi
re='^[a-zA-Z ,.;]' #允许大小写字母和空格、逗号、点、分号
if ! [[ $@ =~ $re ]]; then
  echo 'not a text string'
fi

#!/bin/bash
header_field_count=$(cat sample_data.txt | awk -F '|' '{print NF}' |head -1)
echo 'header_field_count:' $header_field_count
number_of_lines=$(wc -l < sample_data.txt)
echo 'number of lines to process in file:' $number_of_lines
let current_line=2 #跳过第一行，因为那是标题
data_field_count_array=($(cat sample_data.txt | awk -F '|' '{print NF -1}')) # 注意NF -1，因为这些行末尾有一个额外的分隔符
while [ $current_line -lt $number_of_lines ]; do
  echo 'line:' $current_line 'has' ${data_field_count_array[$current_line-1]} 'fields' #bash数组从零开始索引，因此要减1（第1行的索引为0）
  if [[ ${data_field_count_array[$current_line-1]} == $header_field_count ]]; then
    echo 'EQUAL to the Header'
  else
    echo 'NOT EQUAL to the Header'
  fi
  let current_line+=1
done
fieldstocheck=("Amount" "<Item Name>")  #要检查的字段名称；数组可以扩展
fieldtypecheck=("num" "string")     #我们指定检查要求（例如，Customer ID需要
<details>
<summary>英文:</summary>
**NOTE: do not forget that if statements use `==` to compare and not `=` otherwise I think your code might work if you correct this.**
I replicated the setup like so. I added a few lines that have more/fewer fields for the demo. Contents of sample_data.txt:

Here is the script test.sh:

when running this is the output:

it will work with any number of data lines
You can do more research and add more validation example to check if fields are valid numbers. See: https://stackoverflow.com/questions/806906/how-do-i-test-if-a-variable-is-a-number-in-bash
Example validation of character types:
you can play with this script by calling it:
`./script.sh Test this string for me` will pass the string check
`./script.sh -187.8` will pass the number check

You can add whatever characters like `@` into the brackets if you want to check for e-mails or something.
This is the last edit (the question is too far into details)

</details>