Expect command in bash script

Question

I meet problem with executing expect command with bash variable. I have location given by parameter of the script and I need to use it in send command via expect -c. But I need to give it with " so actually send command is thinking that I've ended typing and is recognizing rest of command as extra characters after close-quote. Thing is like:

#!/bin/bash

SIGN=ppp

expect -cd 'spawn ssh user@host
            expect "Password:"
            send -- "pass\r"
            expect "*~>"
            send -- "find /local/"$SIGN"/ -maxdepth 1 -type d -mtime +30 |xargs rm -rfv\r"
            expect "*~>"
            send -- "exit\r"'

Any idea how to send the variable from bash to expect without double-quotes? BTW - I cannot use keys for ssh

Tiago Lopo · Accepted Answer · 2014-06-20 13:08:35Z

1

You can escape like that '"$SIGN"':

ex:

#!/bin/bash

SIGN=ppp

expect  -c 'spawn ssh tiago@localhost
            expect "password:"
            send -- "mypass\r"
            expect "~"
            send -- "echo '"$SIGN"'\r"
            expect "^ppp"
            send -- "exit\r"'

answered Jun 20, 2014 at 13:08

Tiago Lopo

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Comments

Robert Ekendahl · Accepted Answer · 2014-06-20 12:38:12Z

0

What happens if you simply remove the "s around $SIGN?

send -- "find /local/$SIGN/ -maxdepth 1 -type d -mtime +30 |xargs rm -rfv\r"

alternatively try using {} around it.

send -- "find /local/${SIGN}/ -maxdepth 1 -type d -mtime +30 |xargs rm -rfv\r"

answered Jun 20, 2014 at 12:38

Robert Ekendahl

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4 Comments

jester2580 Over a year ago

Without it, it's not considering it as variable: can't read "SIGN": no such variable. the same with {}

Robert Ekendahl Over a year ago

Weird. I think it's because it's inside the '' from the first line. Can you send them as a number of expect commands. One per line and skip the ''s? I'm sure there is a better way but that's where I would start

jester2580 Over a year ago

I actually don't get it. A number of expect commands? Won't it break ssh session? Could You give me a hint? :) I'm actually not familiar with expect at all

Robert Ekendahl Over a year ago

I'm not familiar with expect either. I was just looking at the bash syntax. I think the issue is the use of single quotes to contain the whole string. Take a look at this link stackoverflow.com/a/9420853/3757019. Not sure what the answer is but I think you need to use " instead if '

glenn jackman · Accepted Answer · 2014-06-20 14:42:47Z

0

You could put that variable in the environment:

export SIGN=ppp

expect -cd '
    spawn ssh user@host
    expect "Password:"
    send -- "pass\r"
    expect "*~>"
    send -- "find /local/$env(SIGN)/ -maxdepth 1 -type d -mtime +30 |xargs rm -rfv\r"
    # ...................^^^^^^^^^^
    expect "*~>"
    send -- "exit\r"
'

answered Jun 20, 2014 at 14:42

glenn jackman

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Comments

jester2580 · Accepted Answer · 2014-06-23 09:34:25Z

0

I've faced one more problem: send -- "find /local/'"$SIGN"'/ -maxdepth 1 -type d -mtime +30 |grep -v '"$FILTER"' |xargs rm -rfv\r" This command is not executing. At least it's putting variables values correctly. But there is probably problem sending list of the folders to rm by xargs?

answered Jun 23, 2014 at 9:34

jester2580

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