How can I prevent `expect` from exiting at EOF when reading data from stdin?

Question

When I run echo "passphrase" | expect expect.exp "hostname", everything works fine, but expect exits immediately.

expect.exp

#!/usr/bin/expect

set passphrase [gets stdin]

set hostname [lindex $argv 0]

spawn ssh admin@$hostname
expect "passphrase"
send "$passphrase\r"
expect "admin@$hostname"
send "clear\r"
interact

take a look at [sexpect (Expect for Shells)](https://github.com/clarkwang/sexpect) which you can use to write *Expect* scripts with **shell code only**. — pynexj, Sep 09 '19 at 13:58

score 2 · Accepted Answer · answered Sep 09 '19 at 02:29

2

interact does not work when stdin is not a tty. You can pass the password as a command line option, just like the hostname.

answered Sep 09 '19 at 02:29

pynexj

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Thanks for your feedback. Do you know where I can find info about this in the docs? – sunknudsen Sep 09 '19 at 12:56
i did not find this in the doc. its based on my testing result. :) – pynexj Sep 09 '19 at 13:56
see also: https://stackoverflow.com/questions/50698791/expect-script-works-while-invoking-individually-but-not-as-a-salt-state – pynexj Sep 09 '19 at 14:07

score 1 · Answer 2 · answered Sep 09 '19 at 14:35

1

You might want to use the environment to pass the passphrase:

# shell code
export passphrase="pass phrase"
expect expect.exp hostname

# expect code
...
send "$env(passphrase)\r"

answered Sep 09 '19 at 14:35

glenn jackman

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This is what I ended up doing. Will report back in https://stackoverflow.com/a/57842220/4579271. Thanks! – sunknudsen Sep 09 '19 at 14:49

How can I prevent `expect` from exiting at EOF when reading data from stdin?

expect.exp

2 Answers2

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