Expect is an open source programming language created in 1990.
| #294on PLDB | 34Years Old |
Expect, an extension to the Tcl scripting language written by Don Libes, is a program to automate interactions with programs that expose a text terminal interface. Expect was originally written in 1990 for Unix systems, but has since become available for Microsoft Windows and other systems.. Read more on Wikipedia...
# Assume $remote_server, $my_user_id, $my_password, and $my_command were read in earlier
# in the script.
# Open a telnet session to a remote server, and wait for a username prompt.
spawn telnet $remote_server
expect "username:"
# Send the username, and then wait for a password prompt.
send "$my_user_id\r"
expect "password:"
# Send the password, and then wait for a shell prompt.
send "$my_password\r"
expect "%"
# Send the prebuilt command, and then wait for another shell prompt.
send "$my_command\r"
expect "%"
# Capture the results of the command into a variable. This can be displayed, or written to disk.
set results $expect_out(buffer)
# Exit the telnet session, and wait for a special end-of-file character.
send "exit\r"
expect eof#timeout is a predefined variable in expect which by default is set to 10 sec
#spawn_id is another default variable in expect.
#It is good practice to close spawn_id handle created by spawn command
set timeout 60
spawn ssh $user@machine
while {1} {
expect {
eof {break}
"The authenticity of host" {send "yes\r"}
"password:" {send "$password\r"}
"*\]" {send "exit\r"}
}
}
wait
close $spawn_id| Feature | Supported | Example | Token |
|---|---|---|---|
| Comments | ✓ | # A comment | |
| Line Comments | ✓ | # A comment | # |
| Semantic Indentation | X |