Mixing Expect和BASH

Question

我已经编写了一个小型的Expect脚本来登录到思科设备;一旦登录，我想反复运行命令并输出grep。

#!/usr/bin/expect 

send_user "Device name: " 
expect_user -re "(.*)\n" 
set host $expect_out(1,string) 

send_user "Username: " 
expect_user -re "(.*)\n" 
set user $expect_out(1,string) 

stty -echo 
send_user -- "Password: " 
expect_user -re "(.*)\n" 
set pass $expect_out(1,string) 
stty echo 

send_user "show int " 
expect_user -re "(.*)\n" 
set intf $expect_out(1,string) 
send_user "\n" 

spawn telnet $host 
expect "Username:" 
send "$user\r" 
expect "Password:" 
send "$pass\r" 
expect ">" 

此时我们已经登录到设备，我想重复执行命令“show int xxx”，并为特定行输出grep。 grep不在预期中，也不是像sleep这样的命令，所以我可以循环执行我的特定行中的show int命令，grepping。我如何将Expect和Bash混合在一起？

UPDATE：我现在已经完成了这个脚本，一旦我完成了这个最后的障碍，我会发布完整的脚本。一行set bytesnow [exec grep "packets input" \< showint | cut -d \ -f 9]正在抛出错误;

child process exited abnormally 
    while executing 
"exec grep "packets input" < \showint | cut -d \ -f 9" 

但它在我写的测试脚本中正常工作。文件./showint在那里，在命令行上运行该命令工作正常？我无法弄清楚什么是错的？

UPDATE：更多的调查（http://wiki.tcl.tk/8489）已经表明我，grep退出时的状态码1，这意味着没有模式匹配被发现了，把命令从工作就好命令行？即使使用/ full/path/to/showint。

END：我解决了我的错误，意识到我过去的傻子，下面回答。感谢所有您的帮助：d

Answer 1

这是我的第一个Expect脚本，它的目的是给出一个接口的实时（几乎1秒！）吞吐量。下面的例子给出了接口输入速度，因为我们grep为包含“数据包输入”的行。将其更改为“数据包输出”以获取该接口的实时输出速率。

#!/usr/bin/expect 

# Long delay for those tricky hostnames 

set timeout 60 

# Prompt user for device name/IP, username, password, 
# and interface to query (gi0/2) 

send_user "Device name: " 
expect_user -re "(.*)\n" 
set host $expect_out(1,string) 

send_user "Username: " 
expect_user -re "(.*)\n" 
set user $expect_out(1,string) 

stty -echo 
send_user "Password: " 
expect_user -re "(.*)\n" 
set pass $expect_out(1,string) 
send_user "\n" 
stty echo 

send_user "show int " 
expect_user -re "(.*)\n" 
set intf $expect_out(1,string) 
send_user "\n" 

spawn telnet $host 
expect "Username:" 
send "$user\r" 
expect "Password:" 
send "$pass\r" 
expect ">" 

set byteslast 0 
set bytesnow 0 

log_user 0 

# Enter a continuous loop grabbing the number of bytes that 
# have passed through an interface, each second. 
# The different in this number each cycle, is essentially 
# how much traffic this interface is pushing. 

while { true } { 
    send "show int $intf\r" 
    expect ">" 

    set showint [open "showint" "w"] 
    puts $showint $expect_out(buffer) 
    close $showint 

    set bytesnow [exec grep "packets input" \< showint | cut -d \ -f 9] 

    if { $bytesnow > $byteslast } { 
    set diff [expr $bytesnow - $byteslast] 
    set bps [exec expr "$diff" \* 8] 
    set kbps [exec expr "$bps" \/ 1000] 
    } elseif { $bytesnow < $byteslast } { 
    set diff [expr $byteslast - $bytesnow] 
    set bps [exec expr "$diff" \* 8] 
    set kbps [exec expr "$bps" \/ 1000] 
    } elseif { $bytesnow == $byteslast } { 
    set kbps 0 
    } 

    set byteslast $bytesnow 
    puts "$kbps Kbps\r" 

    sleep 1 
} 

因为这是我的第一个Expect脚本，我毫不怀疑它可以更有效和更明确的书面（总是这样，我觉得），因此，如果任何人有这个任何指针我所有的耳朵！ :)

我的exec grep命令的问题竟然是在那之前，我打开“showint”的文件，我没有关闭，并且我试图访问另一个文件;学校男孩错误！

Answer 2

这是我会做什么

log_user 0 
while(1) { 
    send -- "sh int $intf | i packets input\r" 
    set timeout 5 
    expect { 
    -re "^ +(\d+) packets" { send_user -- "$expect_out(1,string)" } 
    timeout { send_user "broke?\n" } 
    } 
} 

这会让你输入数据包的数量。