bash - 每个循环上的 shell 脚本中的增量数

Question

#!/bin/bash

echo SCRIPT: $0
echo "Enter Customer Order Ref (e.g. 100018)"
read P_CUST_ORDER_REF
echo "Enter DU Id (e.g. 100018)"
read P_DU_ID

P_ORDER_ID=${P_CUST_ORDER_REF}${P_DU_ID}


#Loop through all XML files in the current directory
for f in *.xml
do
  #Increment P_CUST_ORDER_REF here
done

在 for 循环中，每次循环时如何将 P_CUST_ORDER_REF 增加 1

so it READs 10000028 uses it on first loop
2nd 10000029
3rd 10000030
4th 10000031

Answer 1

((P_CUST_ORDER_REF+=1))

或者

let P_CUST_ORDER_REF+=1

Answer 2

P_CUST_ORDER_REF=$((P_CUST_ORDER_REF+1))

Answer 3

您可以使用后增量运算符：

(( P_CUST_ORDER_REF++ ))

我建议：

• 习惯性地使用小写或混合大小写的变量名，以避免与 shell 或环境变量的潜在名称冲突
• 扩展时引用所有变量
• 通常使用-rwith read 来防止反斜杠被解释为转义
• 验证用户输入

例如：

#!/bin/bash
is_pos_int () {
    [[ $1 =~ ^([1-9][0-9]*|0)$ ]]
}

echo "SCRIPT: $0"

read -rp 'Enter Customer Order Ref (e.g. 100018)' p_cust_order_ref
is_pos_int "$p_cust_order_ref"

read -rp 'Enter DU Id (e.g. 100018)' p_du_id
is_pos_int "$p_dui_id"

p_order_id=${p_cust_order_ref}${p_du_id}

#Loop through all XML files in the current directory
for f in *.xml
do
    (( p_cust_order_ref++ ))
done