如果循環無法正常工作

Question

在我的腳本中，我在if循環中第一次執行正確時執行第三次執行後它不能正常工作，我該怎麼做是任何錯誤啊......？請解決我的問題...？在腳本中，我給了客戶名稱作爲ABC的價值，然後我又給了ABC，那時候它正確地發現了if條件，但是我給了第三次ABC，因爲它不能正常工作。

#!/bin/bash 

echo " --- Enter the Database name ---" 
read databasename 


echo " --- enter the table name --- " 
read table_name 

sqlite3 $databasename.db "DROP TABLE IF EXISTS $table_name;" 

sqlite3 $databasename.db "CREATE TABLE IF NOT EXISTS $table_name(cus_id INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE,cus_name TEXT NOT NULL UNIQUE ,cus_domain TEXT UNIQUE, cus_status TEXT NOT NULL,Port INTEGER NOT NULL);" 


echo " --- Enter the total number of rows do you want ---" 
read cus_count 


echo "--- Enter the following details one by one---" 

port_num=8080 

for((i=1;i<=cus_count;i++)) 
do 


echo "enter the $i customer details" 

echo "---Enter the customer name---" 
read c_name 

customer=$(sqlite3 $databasename.db "select cus_name from $table_name") 



if [[ "$port_num" == "$port_num" ]]; then 
port_num=$(($port_num + 1)) 
fi 


if [[ $c_name != $customer ]] 
then 
    echo "---Enter the Status(Active/Inactive)---" 
    read c_status 



c_domain="$c_name" 

else 
    echo "---OOPS you entered customer name already available---" 
    echo "---Please enter new customer name---" 

i=$(($i - 1)) 

fi 

sqlite3 $databasename.db "INSERT OR IGNORE INTO $table_name (cus_name,cus_domain,cus_status, Port) VALUES(\"$c_name\",\"${c_domain,,}.com\",\"$c_status\",\"$port_num\") ;" 


done 

echo " --- Records from the $table_name ---" 

sqlite3 $databasename.db "select * from $table_name;" 

Answer 1

請參閱下面的 「bash腳本運算」

http://tldp.org/LDP/abs/html/arithexp.html

或

http://tldp.org/LDP/abs/html/ops.html