in my test file, I had this line hello$LG. So, if I do
`cat /test`
It will show in my bash shell - hello$LG
But when I try to do this in my expect script,
$> expect test.sh `cat /test`
It gives me this {hello$LG} . I don't know why it is getting {}. Anyone knows how to fix this?
Expect is based upon TCL, you should use square brackets to execute code. When trying to execute a shell command you should use either exec or open or spawn.
I am not sure what the test.sh does, but
expect [exec test.sh 'cat /test']
might just do the trick.
There's more on running other programs from Tcl here:
http://www.tcl.tk/man/tcl/tutorial/Tcl26.html
Related
I want to log into server based on user's choice so I wrote bash script. I am totally newbie - it is my first bash script:
#!/bin/bash
echo -e "Where to log?\n 1. Server A\n 2. Server B"
read to_log
if [ $to_log -eq 1 ] ; then
echo `ssh user#ip -p 33`
fi
After executing this script I am able to put a password but after nothing happens.
If someone could help me solve this problem, I would be grateful.
Thank you.
The problem with this script is the contents of the if statement. Replace:
echo `ssh user#ip -p 33`
with
ssh user#ip
and you should be good. Here is why:
Firstly, the use of back ticks is called "command substitution". Back ticks have been deprecated in favor of $().
Command substitution tells the shell to create a sub-shell, execute the enclosed command, and capture the output for assignment/use elsewhere in the script. For example:
name=$(whoami)
will run the command whoami, and assign the output to the variable name.
the enclosed command has to run to completion before the assignment can take place, and during that time the shell is capturing the output, so nothing will display on the screen.
In your script, the echo command will not display anything until the ssh command has completed (i.e. the sub-shell has exited), which never happens because the user does not know what is happening.
You have no need to capture the output of the ssh command, so there is no need to use command substitution. Just run the command as you would any other command in the script.
I have written the following code:
#!/bin/bash
#Simple array
array=(1 2 3 4 5)
echo ${array[*]}
And I am getting error:
array.sh: 3: array.sh: Syntax error: "(" unexpected
From what I came to know from Google, that this might be due to the fact that Ubuntu is now not taking "#!/bin/bash" by default... but then again I added the line but the error is still coming.
Also I have tried by executing bash array.sh but no luck! It prints blank.
My Ubuntu version is: Ubuntu 14.04
Given that script:
#!/bin/bash
#Simple array
array=(1 2 3 4 5)
echo ${array[*]}
and assuming:
It's in a file in your current directory named array.sh;
You've done chmod +x array.sh;
You have a sufficiently new version of bash installed in /bin/bash (you report that you have 4.3.8, which is certainly new enough); and
You execute it correctly
then that should work without any problem.
If you execute the script by typing
./array.sh
the system will pay attention to the #!/bin/bash line and execute the script using /bin/bash.
If you execute it by typing something like:
sh ./array.sh
then it will execute it using /bin/sh. On Ubuntu, /bin/sh is typically a symbolic link to /bin/dash, a Bourne-like shell that doesn't support arrays. That will give you exactly the error message that you report.
The shell used to execute a script is not affected by which shell you're currently using or by which shell is configured as your login shell in /etc/passwd or equivalent (unless you use the source or . command).
In your own answer, you say you fixed the problem by using chsh to change your default login shell to /bin/bash. That by itself should not have any effect. (And /bin/bash is the default login shell on Ubuntu anyway; had you changed it to something else previously?)
What must have happened is that you changed the command you use from sh ./array.sh to ./array.sh without realizing it.
Try running sh ./array.sh and see if you get the same error.
Instead of using sh to run the script,
try the following command:
bash ./array.sh
I solved the problem miraculously. In order to solve the issue, I found a link where it was described to be gone by using the following code. After executing them, the issue got resolved.
chsh -s /bin/bash adhikarisubir
grep ^adhikarisubir /etc/passwd
FYI, "adhikarisubir" is my username.
After executing these commands, bash array.sh produced the desired result.
I am writing a simple bash script (checkServs.sh) that will ssh into a list of servers and perform a health check on them.
I keep getting errors on the following line:
SERVERS=(blah1.example.com blah2.example.com blah3.example.com blah4.example.com)
Error is:
checkServs.sh: 3: checkServs.sh: Syntax error: "(" unexpected
I've checked online examples and this seems correct, isn't it? Thanks in advance!
I don't know about the syntax error, but this should work:
SERVERS="blah1.example.com blah2.example.com blah3.example.com blah4.example.com"
for server in $SERVERS
do
echo $server
done
EDIT: As noted by Jonathan Leffler in a comment, maybe you are not running the script with bash. Other shells, such as dash, may not recognize the array syntax. If that's the case, you can do:
SERVERS=(blah1.example.com blah2.example.com blah3.example.com blah4.example.com)
for i in $(seq 0 3)
do
echo ${SERVERS[$i]}
done
But if you just want to loop through the names and run an SSH command (ie if having an array won't provide useful functionality), the first method is more straightforward.
Your remote server probably calls a different shell when executing commands. Try to add bash -c to your arguments:
ssh user#server bash -c "<your commands>"
Or:
ssh user#server bash < yourscript.sh ## None in yourscript.sh must read input though.
An opening parenthesis starts a subshell, which is not a correct thing to have on the right side of an equals sign. It expects a string expression, not a command.
Quotation marks are used to keep a string expression together.
#!/bin/bash
# Bash commands go here
/usr/bin/expect - << EndMark
This is the expect script
expect commands go here
and here
until:
EndMark
# More bash commands go here.
exit 0
Something like this will allow me to start an expect script from within bash. However when it gets to the More bash commands part, it will stop the expect process (and the processes it spawned) Is it possible to get back into the same expect script?
eg - Start expect script
- At a certain point leave the expect to bash operations
- return to the same expect script?
It is not necessary to leave the expect process in order to issue shell commands - you can use the system command from within the expect script.
I'm trying to use expect to talk to a bash script, but I'm missing something. My script is:
#!/bin/bash
echo -n "foo? "
read
echo $REPLY
and my expect script is:
#!/usr/bin/expect
spawn ./script.sh
expect "foo? "
send "bar\r\n"
But I never see bar when I run the expect script. What am I missing here?
Dumb me, I needed to add interact to my expect script so that it can finish "interacting" with the script:
#!/usr/bin/expect
spawn ./script.sh
expect "foo? "
send "bar\r\n"
interact
I found the answer here two minutes after asking this question.
I don't familiar well with expect syntax, but you worth try autoexpect:
autoexpect ./script.sh
It will run script.sh and after you'll finish running it an expect script script.exp will be created in current directory.
After than you can edit it if you need to tune something in it.