Bash脚本不等待阅读

Question

我试图以另一个用户的身份运行命令并以该用户的身份读取输入。由于某些原因，脚本不会在read命令中暂停，我不确定原因。下面是脚本的例子：

#!/bin/bash 
username='anthony' 
sudo -H -u "$username" bash << 'END_COMMAND' 

# Commands to be run as new user 
# ------------------------------- 

echo "#! Running as new user $USER..." 


echo "#! Gathering setup information for $USER..." 
echo -n "Enter your name and press [ENTER]: " 
read name 
echo -n "Enter your email and press [ENTER]: " 
read email 
END_COMMAND 

echo "Done" 

任何想法，这是为什么不停止在read name或read email？

Answer 1

read正在从stdin读取，bash正在从hedooc继承其来自sudo的stdin。如果你想让它来自其他地方，你需要明确。例如：

bash 3<&0 << 'END_COMMAND' 
... 
read <&3 
... 

这不适用于sudo，但是，因为sudo关闭了非标准的文件描述符。但须藤不关闭标准错误，所以如果你能摆脱重复使用的文件描述符，你可能能够做到：

sudo -H -u "$username" bash 2<&0 << 'END_COMMAND' 
... 
read -u 2 email 
... 

但它可能是更安全的事：

sudo -H -u "$username" bash << 'END_COMMAND' 
... 
read email < /dev/tty 
... 

Answer 2

你能让这个脚本检查它是否以sudo方式运行，如果不是，使用sudo执行它本身？

#!/bin/bash 
username='anthony' 

if [[ -z "${SUDO_USER}" ]]; then 
    exec sudo -H -u "${username}" -- $0 
fi 

echo " 
# Commands to be run as new user 
# ------------------------------- 
" 
echo "#! Running as new user $USER..." 

echo "#! Gathering setup information for $USER..." 
echo -n "Enter your name and press [ENTER]: " 
read name 
echo -n "Enter your email and press [ENTER]: " 
read email