期望脚本无法读取变量

Question

I have been trying to pass a variable to expect script, this variable contains the password for an ssh command, however when I try to execute the script, I receive a message stating that the variable couldn't be read - no such variable.

The variable is declared in the shell script, however expect just can't read it.

Here is how the variable is declared:

D=`s="$LIST1" printenv s |grep $ip | awk '{print $3}'`

If I export variable D, then it works, but I can't have this variable exported to all child process, does anyone know how can I add this variable to expect without having to export it?

/usr/bin/expect <<'END_EXPECT'
set timeout -1
log_file  expect-log.txt
spawn -noecho sh ./script.sh
expect "yes" { send "yes\r"}
expect {
    -nocase "*assword*" {
        send "$D\r"
        exp_continue
    }
send \r
    eof

admin@server1's password: can't read "D": no such variable
    while executing
"send "$D\r""
    invoked from within
"expect {
        -nocase "*assword*" {
            send "$D\r"
            exp_continue
        }
    send \r
        eof
    }"

Answer 1

By far the easiest method of getting the variable into expect is by exporting it. You can unexport it after launching expect, and expect can remove the variable from the environment before launching any subprocesses.

You are strongly advised to not embed the expect script within a shell script, but rather to make it a separate file (that uses Tcl highlighting rules, if you're using an editor that supports it). It's just so much easier that way.

# This is bash; other shells have their own quirks
export D=`s="$LIST1" printenv s |grep $ip | awk '{print $3}'`
expect script.expect
unexport D

# Move the variable from the environment to a script variable; DO THIS BEFORE exec OR spawn
set D $env(D)
unset env(D)

set timeout -1
log_file  expect-log.txt
spawn -noecho sh ./script.sh
expect "yes" { send "yes\r"}
expect {
    -nocase "*assword*" {
        send "$D\r"
        exp_continue
    }
send \r
    eof

That code looks incomplete BTW. The braces aren't balanced, the indentation looks strange, and it generally looks like something is missing. You'll have to fix that before everything works.