關聯數組名稱替換和複製bash

Question

我有一個bash腳本，用於檢查輸入日期（$ 1）是否落入日期範圍/範圍內。用戶輸入日期和（a或b，即$ 2）。

#!/usr/bin/env bash 

today=$(date +"%Y%M%d") 
declare -A dict=$2_range 
a_range=(["20140602"]="20151222" ["20170201"]="$today") 
b_range=(["20140602"]="20150130") 

for key in ${!dict[@]}; do 
    if [[ $1 -le ${dict[$key]} ]] && [[ $1 -ge $key ]]; then 
    echo $1 falls in the range of $2 
    fi 
done 

我不知道如何將關聯數組複製到dict變量。 樣本用法

$ ./script.sh 20170707 a 

    20170707 falls in the range of a 

Answer 1

您根本不需要複製任何東西;你只需要一個別名。

#!/usr/bin/env bash 

today=$(date +"%Y%M%d") 

# you need declare -A **before** data is given. 
# previously, these were sparse indexed arrays, not associative arrays at all. 
declare -A a_range=(["20140602"]="20151222" ["20170201"]="$today") 
declare -A b_range=(["20140602"]="20150130") 

# declare -n makes dict a reference to (not a copy of) your named range. 
declare -n dict="$2_range" 

for key in "${!dict[@]}"; do 
    if (($1 <= ${dict[$key]})) && (($1 >= key)); then 
    echo "$1 falls in the range of $2" 
    fi 
done 

declare -n是在bash（4.3+）的ksh93的特徵nameref的版本;見http://wiki.bash-hackers.org/commands/builtin/declare#nameref