I am trying to call a shell script and store the result in an expect variable. get_pw.sh accepts 2 args and decrypts the file using the provided md5hash. If I execute ./get_pw.sh file.test md5hash from the bash prompt it returns the password string as expected. When called from expect, the password does not get returned. The expect debug shows:
expect: does "" (spawn_id exp0) match regular expression "[^\s]"?
So it looks like the script is not returning the password string when called from expect. Relevant code:
#!/usr/bin/expect
send "./get_pw.sh file.test md5hash \r"
expect -re {[^\s]} {
set password $expect_out(0,string)
}
puts "The password is: $password"
You need to spawn a command first before you can send input and expect output from it.
To set an expect variable to the output of a command, use
set varname [exec command]
If you must do this with expect,
log_user 0
spawn -noecho get_pw.sh file hash
expect eof
set passwd [string trimright $expect_out(buffer) "\r\n"]
puts $passwd
Jens's answer looks pretty good by now ...
Related
for some time I am struggling to get the exit code of a script which I am running from within expect.
It is a BASH script and the questionable part looks like this:
expect -c "
log_file $LOG
spawn su - $ora_user
expect ""
send \"source $oraenv_binary\r\"
expect \"ORACLE_SID = \[$ora_user\] \?\"
send \"$SID\r\"
expect \"The Oracle base has been set to /oracle/$SID\"
send \"$execPATHroot/$subscript $args_subscript\r\"
expect ""
send \"echo \$?\r\"
expect -re \"(\\d+)\" {
set result \$expect_out(1,string)
}
send_user \"subscript exit code: \$result\"
log_file
send \"exit\r\"
expect ""
exit [lindex \$result 3]"
sub_rc=$?
Needed to say that this is one of many tries to get the code, however, unsuccessfully. I guess that my problem lies in incorrectly escaped characters or wrong use of brackets.....
When debugging, I am getting the following:
[336] oraenv_binary=/usr/local/bin/oraenv
[338] expect -c '
log_file /var/opt/osit/oracle/log/ora_sbp_patching_root.bash.log
spawn su - oracle
expect
send "source /usr/local/bin/oraenv\r"
expect "ORACLE_SID = \[oracle\] \?"
send "H95\r"
expect "The Oracle base has been set to /oracle/H95"
send "/opt/osit/oracle/bin/ora_sbp_patching_orausr.bash -s H95 -a CHECK -p /imports/e2r2s48ifde0002/CDSAP/DB/oracle/ORA19/SBP/SBP_1915_220419_202205 -h /imports/e2r2s48ifde0002/CDSAP/DB/oracle/ORA19/SBP/SBP_1915_220419_202205/README19P_2205-70004508.HTM -u oracle\r"
expect
send "echo $?\r"
expect -re "(\d+)" {
set result $expect_out(1,string)
}
send_user "subscript exit code: $result"
log_file
send "exit\r"
expect
exit [lindex $result 3]'
.....subscript runs here OK with exit code 0 in this case
-sh-4.2$ subscript exit code: decho $?
0
-sh-4.2$ exit
logout
expected integer but got ""
while executing
"exit [lindex $result 3]"
[357] sub_rc=0
It seems to me that the regex part "(\d+)" is not OK, but perhaps, it is completely a mess... :-)
Please help.
I have read and tried these recommendations:
Is there a way to expect output without removing it from the buffer in Tcl expect?
https://wiki.tcl-lang.org/page/How+Expect+can+capture+the+exit+code+from+a+remote+command
https://www.unix.com/shell-programming-and-scripting/144812-expect-script-obtain-exit-code-remote-command.html
You have this
expect -re "(\d+)" {
set result $expect_out(1,string)
}
send_user "subscript exit code: $result"
and we can see the output is
-sh-4.2$ subscript exit code: decho $?
0
Because the regular expression "(\d+)" is in double quotes, backslash substitutions will occur, and the pattern becomes (d+) which may not match (do you get a 10 second delay at that point?) -- I suspect this is why $result is empty.
Backslashes are prevalent in regular expressions. Using braces to quote them is the way to go:
expect -re {\d+} {set result $expect_out(0,string)}
Running your expect code with expect -d (or set exp_internal 1 in the code) emits very verbose expect debug output that is extremely useful to see how your patterns are matching (or not).
Using quoted shell heredocs is (IMO) preferable to using quoted strings to encapsulate code.
Consider
expect -c "
send_user \"my home is \$env(HOME)\\n\"
"
versus
expect << 'END_CODE'
send_user "my home is $env(HOME)\n"
END_CODE
With this technique, you pass shell variable to expect through the environment:
export ora_user=oracle
expect << 'END_EXPECT'
#...
spawn su - $env(ora_user)
END_EXPECT
thanks a lot for your answer Glenn, interesting points mentioned.
Regarding the braces versus double quotes - I have changed it like that, but no effect. I have those double quotes escaped by backslash within my code - I think the effect is the same, however, definitely it looks nicer to me and evidently it is safer.
I have played with the debug mode of expect - thanks for that, I can see much more info.
I have noticed that expect holds much more stuff than I "expected" :-)
==> this is just a snippet:
.\r\n-sh-4.2$ " (spawn_id exp7) match regular expression "\d+"? (No Gate, RE only) gate=yes re=yes
expect: set expect_out(0,string) "4"
expect: set expect_out(spawn_id) "exp7"
expect: set expect_out(buffer) "\r\n-sh-4"
can't read "expect_out(1,string)": no such element in array
while executing
"set result $expect_out(1,string)"
invoked from within
"expect -re {\d+} {set result $expect_out(1,string)}"
As you can see, when I am sending the subscript to be executed I am expecting "" i.e. nothing, just the new prompt line.
However, at that point expect is full of stuff, not at all blank - I think, I need to define the prompt exactly:
-sh-4.2$
and then I need to expect it, together with echoed exit code $? and somehow separate exit code integer to get what I want...... I will keep trying.
The final code which works is as follows (much of the credit goes to Glenn for his numerous advices) :
expect -c "
log_file $LOG
spawn su - $ora_user
expect -re {\$ $}
send \"PS1='>'\r\"
expect -re {>$}
send \"source $oraenv_binary\r\"
expect {ORACLE_SID = \[$ora_user\] ? }
send \"$SID\r\"
expect \"The Oracle base has been set to /oracle/$SID\"
send \"$execPATHroot/$subscript $args_subscript\r\"
expect { (subscript) ; exp_continue }
expect -re {>$}
send \"echo \$?\r\"
expect -re {(\d+)\r\n>$} {set result \$expect_out(1,string)}
send_user \"subscript exit code:\$result\n\"
log_file
send \"exit\r\"
expect \"logout\"
exit [lindex \$result 0]"
sub_rc=$?
echo sub_rc:$sub_rc
The first thing after spawn su - $ora_user is to set the prompt by send \"PS1='>'\r\" in order to make new lines with prompt less intrusive to expect.
Then after send \"$execPATHroot/$subscript $args_subscript\r\" I have used the fact, that I have written the subscript to have every line of output populated by (subscript) keyword. So while the subscript produces the output, the expect keeps going by exp_continue.
When the $subscript ends, the prompt > appears into which the expect sends echo $? to get exit code of the $subscript.
This appears on the screen as:
>echo $?
0
>
so the code should expect the integer, return and the new line with prompt - i.e. {(\d+)\r\n>$}. At that time the expect matches the output and expect_out(1,string) is correctly populated:
send: sending "echo $?\r" to { exp7 }
Gate keeper glob pattern for '(\d+)\r\n>$' is '*
>'. Activating booster.
expect: does "" (spawn_id exp7) match regular expression "(\d+)\r\n>$"? Gate "*\r\n>"? gate=no
echo $?
0
>
expect: does "echo $?\r\n0\r\n>" (spawn_id exp7) match regular expression "(\d+)\r\n>$"? Gate "*\r\n>"? gate=yes re=yes
expect: set expect_out(0,string) "0\r\n>"
expect: set expect_out(1,string) "0"
expect: set expect_out(spawn_id) "exp7"
expect: set expect_out(buffer) "echo $?\r\n0\r\n>"
Another thing to mention is \n within send_user \"subscript exit code:\$result\n\" so to have new line next..
The last change to the code in question is:
exit [lindex \$result 0]"
I have changed the index to 0 as variable result has just one item and index 0 stands for 1st item in the list.
I wrote the following expect script:
set prompt {$}
set domain $::env(METEOR_DOMAIN)
puts "$domain"
spawn meteor mongo "$domain" --url
set pass "mypassword"
expect {
Password: {
send "$pass\r";
}
}
expect $prompt
puts "The output is '$expect_out(buffer)'."
and the puts command outputs:
The output is ' mypassword
mongodb://client:56099867-e806-3a7a-e5b4-93127e0a3b42#production-db-a1.meteor.io:27017/db_meteor_com'.
which I imagine is what is in the buffer, but I only want the second part (e.g.) the mongo string
How do I make expect only put the last part the buffer or only retrieve the last part in the buffer for storage in an environmental variable?
You can turn off stdout output before the password, and turn it back on afterward. Furthermore, you can parse the output and extract the mongo string. Here is one way to do it:
log_user 0
spawn ...
expect "Password:" {
send "mypassword\r"
}
log_user 1
...
if {[regexp -line {^mongodb:.*$} $expect_out(buffer) url]} {
set url [string trimright $url]
puts "URL is: '$url'"
}
According to the documentation, log_user 0 will turn off stdout, and log_user 1 will turn it back on.
I need to be able to return a different password after the first one fails which will be the second time the prompt asks for the same expect value "Password:"
(expect -c "
#exp_internal 1
set passwords {PASS1 PASS2}
set index 0
set timeout 20
# Start the session with the input variable and the rest of the hostname
spawn telnet $host
set timeout 3
expect {
-ex \"Password:\" {
send \"[lindex $passwords $index]\r\"
incr index
exp_continue;
}
}
I just can't get it to work. It looks like there is nothing in the lindex send:
-ex "Password:" {
send "[lindex ]\r"
The problem is you're using double quotes to group the expect script -- bash is interpreting the $variables as bash variables. You need to either:
use single quotes to delimit the script, or
escape all the \$expect_variables so bash does not substitute them first.
I want to get the terminal userID by using whoami command. I have given my script below, but it just returns the command name, instead of username?
How can I get terminal user id using whoami command?
My code is,
send "whoami\r"
set timeout 5
expect -re {([a-z]+)} {
set jobid $expect_out(0,string)
}
send_user "\r\nUSER $jobid\r\n"
}
Output for the above code is,
asisdtt-exp7$ whoami
USER whoami
kandabap
asisdtt-exp7$ exit
When I hardcode the first letter of my expected userID (kandabap), I am getting the answer correct. That code is,
send "whoami\r"
set timeout 5
expect -re {k([a-z]+)} {
set jobid $expect_out(0,string)
}
send_user "\r\nUSER $jobid\r\n"
Output,
asisdtt-exp7$ whoami
kandabap
asisdtt-exp7$
USER kandabap
I am very much confused.
I'm not sure what you're really trying to do, but this will work just fine:
log_user 0
spawn whoami
expect eof
set jobid $expect_out(buffer)
puts "USER $jobid"
Of course, none of that's really needed. You can do the same thing using plain TCL:
puts "USER [exec whoami]"
I have a bash+expect script which has to connect via ssh to the remote comp (and i can't use ssh keys, need password identification in here), read the file there, find specific line with the "hostname" (like "hostname aaaa1111") and store this hostname into the variable to be used after while. How can i get the value of the "hostname" parameter? I thought that line content will be in $expect_out(buffer) variable (so i can scan it and analyze), but it's not. My script is:
#!/bin/bash
----bash part----
/usr/bin/expect << ENDOFEXPECT
spawn bash -c "ssh root#$IP"
expect "password:"
send "xxxx\r"
expect ":~#"
send "cat /etc/rc.d/rc.local |grep hostname \r"
expect ":~#"
set line $expect_out(buffer)
puts "line = $line, expect_out(buffer) = $expect_out(buffer)"
...more script...
ENDOFEXPECT
When i try to see line variable, i see only this: line = , expect_out(buffer) = (buffer) What is the right way to get the line from the file into the variable?
Or is it possible to open the file on the remote computer with expect, scan the file and get what i need to the variable?
Here http://en.wikipedia.org/wiki/Expect there is an example:
# Send the prebuilt command, and then wait for another shell prompt.
send "$my_command\r"
expect "%"
# Capture the results of the command into a variable. This can be displayed,
set results $expect_out(buffer)
seems that it doesn't work in this case?
You might just want to try and do it all from expect, as expect can control bash.
The following should do what you've described. Not sure if this is exactly what you are trying to do.
#!/bin/sh
# the next line restarts using tclsh \
exec expect "$0" "$#"
spawn bash
send "ssh root#$IP\r"
expect "password:"
send "xxxx\r"
expect ":~#"
send "cat /etc/rc.d/rc.local |grep hostname \n"
expect ":~#"
set extractedOutput $expect_out(buffer)
set list [split $extractedOutput "\n"]
foreach line $list {
set re {(?x)
.*
(*)
-S.*
}
regexp $re $line total extractedValue
if {[info exists extractedValue] && [string length $extractedValue] > 1} {
set exportValue $extractedValue
break # We've got a match!
}
send "exit\r" # disconnect from the ssh session
if {[info exists exportValue] && [string length $exportValue] > 1}{
send "export VARIABLE $exportValue\r"
} else {
send_user "No exportValue was found - exiting\n"
send "exit\r"
close
exit 1
}
# now you can do more things in bash if you like