期待内部bash +错误#args：应该是“foreach varList list？varList list ...？command”

Question

我在bash脚本中使用expect脚本。当我在期望脚本中使用foreach时，它会抛出

  

错误#args：应该是“foreach varList list？varList list ...？command”

代码：

#!/bin/bash

read -p "Enter username: " username
read -s -p "Enter password: " password

#Expect script
/bin/expect -<<EOD 

set SERVERS {100 101 102}

foreach SERVER $SERVERS {
set timeout -1
spawn scp ${username}@plsa${SERVER}.corp.com:/log.2011-11-24 ${SERVER} 
expect "*password:"; send "$password\r"
expect eof }
EOD

echo "completed"

由于

Answer 1

heredoc（<<ENDTOK）在$variables上受到shell扩展。这意味着对于您希望解释的每个$variable，您需要转义$。

---

逃避某事的方法是在其前面添加一个斜杠（$ - ＆gt; \$）。
看来用户名和密码应该来自shell，其余来自期望，所以这是应该如何：

#!/bin/bash

read -p "Enter username: " username
read -s -p "Enter password: " password

#Expect script
/bin/expect -<<EOD 

set SERVERS {100 101 102}

foreach SERVER \$SERVERS {
set timeout -1
spawn scp ${username}@plsa\${SERVER}.corp.com:/log.2011-11-24 \${SERVER} 
expect "*password:"; send "$password\r"
expect eof }
EOD

echo "completed"

请注意\和$SERVERS前面的${SERVER}。

Answer 2

您需要使用反斜杠转义美元符号，因为$name已用于变量name的值：

/bin/expect -<<EOD 

set SERVERS {100 101 102}

foreach SERVER \$SERVERS {
set timeout -1
spawn scp ${username}@plsa\${SERVER}.corp.com:/log.2011-11-24 \${SERVER} 
expect "*password:"; send "$password\r"
expect eof }
EOD

Answer 3

如果引用here-document分隔符，嵌入式脚本也会被有效引用：

/bin/expect -<<'EOD' 
... expect script as posted ...
EOD