尝试使用 jq 分配多个变量

Question

我有一个名为$db_main_info的变量，其中包含以下字符串

 { "host": "env-prod-blah-db.blah.us-east-1.rds.amazonaws.com", "dbname": "blahblah", "user": "foobar", "password": "foopassfoopass" }

我正在做以下事情

read host dbname user password < <(echo $db_main_info | jq -r '.host, .dbname, .user, .password')

在执行上述语句后，当我执行echo $host时，它会打印以下内容

env-prod-blah-db.blah.us-east-1.rds.amazonaws.com

然而，其他 3 个变量dbname 、 user和password永远不会被设置。 我不确定我做错了什么？

我希望变量dbname取值blahblah和变量 user 取值foobar和变量password取值foopassfoopass

Answer 1

jq将每个字段打印在单独的行上，但read默认情况下只读取一行。 一种方法是修改read的默认行为，通过将换行符分配给IFS ，将这个字符设置为用作字段分隔符，并将行分隔符设置为 null 字符串（这样换行符不再用作用于指示行尾的分隔符）：

#!/bin/bash

db_main_info='{ "host": "env-prod-blah-db.blah.us-east-1.rds.amazonaws.com", "dbname": "blahblah", "user": "foobar", "password": "foopassfoopass" }'

IFS=$'\n' read -r -d '' host dbname user password < <(jq -r '.host, .dbname, .user, .password' <<< "$db_main_info")
echo "host=$host"
echo "dbname=$dbname"
echo "user=$user"
echo "password=$password"

Answer 2

可以单独运行jq看看是什么问题：

$ echo "$db_main_info" | jq -r '.host, .dbname, .user, .password'
env-prod-blah-db.blah.us-east-1.rds.amazonaws.com
blahblah
foobar
foopassfoopass

有四行，每行一个字段。 你假设它是一行有四个字段。

您可以改为读取多行并将每行分配给变量：

db_main_info=' { "host": "env-prod-blah-db.blah.us-east-1.rds.amazonaws.com", "dbname": "blahblah", "user": "foobar", "password": "foopassfoopass" }'

for var in host dbname user password
do
  IFS='' read -r "$var"
done < <(echo "$db_main_info" | jq -r '.host, .dbname, .user, .password')

echo "Host: $host, DB name: $dbname, user: $user, password: $password"

这导致：

Host: env-prod-blah-db.blah.us-east-1.rds.amazonaws.com, DB name: blahblah, user: foobar, password: foopassfoopass