14

我正在使用 expect 在我的服务器上启动一个应用程序：

#!/usr/bin/expect

set timeout -1

spawn "bin/start-all.sh"
expect {
    -re "Found MongoDB in" { send "y\r"; exp_continue }
    -re "Found Hadoop in" { send "y\r"; exp_continue }
    -re "Going to start Hadoop" { interact }
}

我可以在脚本运行的几秒钟内访问我的服务器上的应用程序，但一旦它结束，应用程序就变得不可用。

我已经在调试模式下运行 expect 并在最后得到以下输出：

expect: does "vendors area. Do you want to start it? [y/n] y\r\n" (spawn_id exp6) match regular expression "Found MongoDB in"? Gate "Found MongoDB in"? gate=no
"Found Hadoop in "? Gate "Found Hadoop in "? gate=no
"Going to start Hadoop"? Gate "Going to start Hadoop"? gate=no
Going to start Hadoop...

expect: does "vendors area. Do you want to start it? [y/n] y\r\nGoing to start Hadoop...\r\n" (spawn_id exp6) match regular expression "Found MongoDB in"? Gate "Found MongoDB in"? gate=no
"Found Hadoop in "? Gate "Found Hadoop in "? gate=no
"Going to start Hadoop"? Gate "Going to start Hadoop"? gate=yes re=yes
expect: set expect_out(0,string) "Going to start Hadoop"
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) "vendors area. Do you want to start it? [y/n] y\r\nGoing to start Hadoop"
tty_raw_noecho: was raw = 0  echo = 1
interact: received eof from spawn_id exp6
tty_set: raw = 0, echo = 1
tty_set: raw = 5, echo = 0

我已经尝试在最后一种模式下使用exit 0, interact, exp_continue, disconnect,sleep 10以及期待eof但似乎没有任何效果。我也尝试过跑步expect start-all.exp &，但这也不起作用。

当我手动运行 bin/start-all.sh 时，脚本会启动必要的进程然后退出。然而，期望这些进程似乎被杀死了。我将如何解决这个问题？

4

2 回答 2

13

我有同样的问题并想通了。

expect退出时，它会向SIGHUP生成的子进程发送一个（挂断信号）。默认情况下，这SIGHUP会导致生成的进程终止。

如果您希望底层流程不会因您而死，SIGHUP您有两个简单的选择。两者都运作良好：

1）要求在这样的行expect中忽略底层进程：SIGHUPspawn

#!/usr/bin/expect -f
...
spawn -ignore HUP command args...
...
expect_background

2）自己做 - 忽略SIGHUP底层过程本身：

这是演示方法2的工作脚本：

#!/usr/bin/expect -f
#
# start a process and background it after it reaches a certain stage
#
spawn perl -e "\$SIG{HUP} = 'IGNORE'; for (\$a='A';; \$a++) {print qq/value is \$a\\n/; sleep 1;}"

set timeout 600

# Detailed log so we can debug (uncomment to enable)
# exp_internal -f /tmp/expect.log 0

# wait till the subprocess gets to "G"
expect -ex "value is G"

send_user "\n>>> expect: got G\n"

# when we get to G, background the process
expect_background

send_user ">>> spawned process backgrounding successful\n"
exit 0

这是一个正在运行的示例：

$ ./expect-bg
spawn perl -e $SIG{HUP} = 'IGNORE'; for ($a='A';; $a++) {print qq/value is $a\n/; sleep 1;}
value is A
value is B
value is C
value is D
value is E
value is F
value is G

>>> expect: got G
>>> spawned process backgrounding successful

正如 ps 输出中所预期的那样，perl 进程是后台运行的。

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
hankm     6700  0.0  0.0  17696  2984 ?        Ss   18:49   0:00 perl -e $SIG{HUP} = 'IGNORE'; for ($a='A';; $a++) {print qq/value is $a\n/; sleep 1;}
于 2015-09-13T02:04:20.943 回答
0

我发现几乎在所有程序在 Expect 中运行异常的情况下都有效的一件事是在屏幕实例中生成一个 shell 并从那里运行程序。

spawn screen bash
send "bin/start-all.sh\r"

尝试这样做，看看它是否可以解决您过早的 eof 问题。

于 2013-08-29T19:24:06.570 回答