bash 期望中的while循环
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while loops within expect
提问by Pkp
I am using expect within bash. I want my script to telnet into a box, expect a prompt, send a command. If there is a different prompt now, it has to proceed or else it has to send that command again. My script goes like this:
我在bash中使用expect。我想让我的脚本 telnet 到一个盒子里，期待一个提示，发送一个命令。如果现在有不同的提示，它必须继续，否则它必须再次发送该命令。我的脚本是这样的：
\#!bin/bash
//I am filling up IP and PORT1 here
expect -c "
set timeout -1
spawn telnet $IP $PORT1
sleep 1
send \"\r\"
send \"\r\"
set temp 1
while( $temp == 1){
expect {
Prompt1 { send \"command\" }
Prompt2 {send \"Yes\"; set done 0}
}
}
"
Output:
输出：
invalid command name "while("
while executing
"while( == 1){"
Kindly help me.
I tried to change it to while [ $temp == 1] {
请帮助我。
我试着把它改成 while [ $temp == 1] {
I am still facing the error below:
我仍然面临以下错误：
Output:
输出：
invalid command name "=="
while executing
"== 1"
invoked from within
"while [ == 1] {
expect {
回答by glenn Hymanman
This is how I'd implement this:
这就是我要实现的方式：
expect -c '
set timeout -1
spawn telnet [lindex $argv 0] [lindex $argv 1]
send "\r"
send "\r"
expect {
Prompt1 {
send "command"
exp_continue
}
Prompt2 {
send "Yes\r"
}
}
}
' $IP $PORT1
- use single quotes around the expect script to protect expect variables
- pass the shell variables as arguments to the script.
- use "exp_continue" to loop instead of an explicit while loop (you had the wrong terminating variable name anyway)
- 在expect脚本周围使用单引号来保护expect变量
- 将 shell 变量作为参数传递给脚本。
- 使用“exp_continue”来循环而不是显式的 while 循环（无论如何你的终止变量名是错误的）
回答by Bryan Oakley
The syntax for while is "while test body". There must be a spce between each of those parts which is why you get the error "no such command while)"
while 的语法是“while test body”。每个部分之间必须有一个 spce，这就是为什么您会收到错误“同时没有这样的命令）”
Also, because of tcl quoting rules, 99.99% of the time the test needs to be in curly braces. So, the syntax is:
此外，由于 tcl 引用规则，99.99% 的时间测试需要在花括号中。所以，语法是：
while {$temp == 1} {
For more information see http://tcl.tk/man/tcl8.5/TclCmd/while.htm
有关更多信息，请参阅http://tcl.tk/man/tcl8.5/TclCmd/while.htm
(you probably have other problems related to your choice of shell quotes; this answer addresses your specific question about the while statement)
（您可能还有其他与您选择的 shell 引号相关的问题；这个答案解决了您关于 while 语句的具体问题）
