将输出分配给 Bash 中的变量
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Assign output to variable in Bash
提问by Alex Bliskovsky
I'm trying to assign the output of cURL into a variable like so:
我正在尝试将 cURL 的输出分配给一个变量，如下所示：
#!/bin/sh
$IP=`curl automation.whatismyip.com/n09230945.asp`
echo $IP
sed s/IP/$IP/ nsupdate.txt | nsupdate
However, when I run the script the following happens:
但是，当我运行脚本时，会发生以下情况：
./update.sh: 3: =[my ip address]: not found
./update.sh: 3: =[my ip address]: not found
How can I get the output into $IPcorrectly?
我怎样才能$IP正确地得到输出？
回答by ghoti
In shell, you don't put a $ in front of a variable you're assigning. You only use $IP when you're referring to the variable.
在 shell 中，您不会在要分配的变量前放置 $。只有在引用变量时才使用 $IP。
#!/bin/bash
IP=$(curl automation.whatismyip.com/n09230945.asp)
echo "$IP"
sed "s/IP/$IP/" nsupdate.txt | nsupdate
回答by Kostas Demiris
Same with something more complex...getting the ec2 instance region from within the instance.
与更复杂的事情相同……从实例中获取 ec2 实例区域。
INSTANCE_REGION=$(curl -s 'http://169.254.169.254/latest/dynamic/instance-identity/document' | python -c "import sys, json; print json.load(sys.stdin)['region']")
echo $INSTANCE_REGION
