I am new to Ubuntu and Bash scripting. I am working on a project to give a demo on an SDN application to my class. I need some help in scripting to create the demo. Please help in case if you have any idea on what am asking.
The demo uses a tool called mininet. I need just one script so that I can automate the whole of my demo.
The commands I need to run are given in order below.
Run "sudo mn" on the terminal. This changes the prompt from
/mininet$ sudo mn
to
mininet>
Now on this terminal where the prompt is mininet>, I need to run xterm h1 followed by xterm h2 to create separate terminals for two hosts created by mininet.
I have to access the xterm terminal for h1 and run a command there . eg: ifconfig
I have to access the xterm terminal for h2 and run a command there . eg : set ip address
I have to run a ping in xterm terminal for h1 and while this is happening, i want to access terminals of h2 and start a ping in xterm terminals of h2.
I have to go back to the previous terminal from where the xterm terminals were spawned. mininet> prompt one. and run exit and then when the prompt goes back to normal /mininet$ i have to sudo mn -c.
All of this should be done from one script. Please ignore the specific commands mentioned and give a generic solution or clues.
Related
I have written a batch file like this:
Start putty.exe -ssh 172.17.0.52 -l root -m dummy.txt
Then in dummy.text I have written this command:
avahi-daemon --no-drop-root -D
export XVHMI_USERCONFIG_PATH=/home/UserProfileConfig
export XDG_RUNTIME_DIR=/tmp
cd /opt/bosch/airis/bin
When I run the .bat file, PuTTY starts, commands execute (hopefully, not sure) and it exits.
How to keep that window open?
I have googled for the same, but no solid help. I read on stack overflow itself that we need to define something in txt file, but what and most importantly how?
The SSH session closes (and PuTTY with it) as soon as the command finishes. Normally the "command" is shell. As you have overridden this default "command" and yet you want to run the shell nevertheless, you have to explicitly execute the shell yourself:
avahi-daemon ... ; /bin/bash
Also as use of -m switch implies a non-interactive terminal, you probably want to force an interactive terminal back using -t switch.
Though, I'm not really sure if you want to execute shell or if you just want to see your command output. If the latter, did you consider using plink? It's console terminal client from PuTTY package. Being console application, it inherits console of parent batch file, and you can pause the batch console from closing using pause command, if needed.
Another option (both for PuTTY and plink) is to pause on remote side. E.g. Using read command.
avahi-daemon ... ; read
As suggested by Martin I tried this step:
putty.exe -ssh 172.17.0.52 -l root -m dummy.txt -t
added /bin/bash at the end of commands in dummy.txt
It worked for me. Please note, you have to follow both the steps as mentioned above.
This way you can keep the session alive and can manually execute further commands.
I am using elastic map reduce from Amazon. I am sshing into hadoop master node and executing a script like.
$EMR_BIN/elastic-mapreduce --jobflow $JOBFLOW --ssh < hivescript.sh . It sshes me into the master node and runs the hive script. The hivescript contains the following lines
hive
add jar joda-time-1.6.jar;
add jar EmrHiveUtils-1.2.jar;
and some commands to create hive tables. The script runs fine and creates the hive tables and everything else, but comes back to the prompt from where I ran the script. How do I leave it sshed into hadoop master node at the hive prompt.
Consider using Expect, then you could do something along these lines and interact at the end:
/usr/bin/expect <<EOF
spawn ssh ... YourHost
expect "password"
send "password\n"
send javastuff
interact
EOF
These are the most common answers I've seen (with the drawbacks I ran into with them):
Use expect
This is probably the most well rounded solution for most people
I cannot control whether expect is installed in my target environments
Just to try this out anyway, I put together a simple expect script to ssh to a remote machine, send a simple command, and turn control over to the user. There was a long delay before the prompt showed up, and after fiddling with it with little success I decided to move on for the time being.
Eventually I came back to this as the final solution after realizing I had violated one of the 3 virtues of a good programmer -- false impatience.
Use screen / tmux to start the shell, then inject commands from an external process.
This works ok, but if the terminal window dies it leaves a screen/tmux instance hanging around. I could certainly try to come up with a way to just re-attach to prior instances or kill them; screen (and probably tmux) can make it die instead of auto-detaching, but I didn't fiddle with it.
If using gnome-terminal, use its -x or --command flag (I'm guessing xterm and others have similar options)
I'll go into more detail on problems I had with this on #4
Make a bash script with #!/bin/bash --init-file as the shebang; this will cause your script to execute, then leave an interactive shell running afterward
This and #3 had issues with some programs that required user interaction before the shell is presented to them. Some programs (like ssh) it worked fine with, others (telnet, vxsim) presented a prompt but no text was passed along to the program; only ctrl characters like ^C.
Do something like this: xterm -e 'commands; here; exec bash'. This will cause it to create an interactive shell after your commands execute.
This is fine as long as the user doesn't attempt to interrupt with ^C before the last command executes.
Currently, the only thing I've found that gives me the behavior I need is to use cmdtool from the OpenWin project.
/usr/openwin/bin/cmdtool -I 'commands; here'
# or
/usr/openwin/bin/cmdtool -I 'commands; here' /bin/bash --norc
The resulting terminal injects the list of commands passed with -I to the program executed (no parms means default shell), so those commands show up in that shell's history.
What I don't like is that the terminal cmdtool provides feels so clunky ... but alas.
There is an interactive shell console, I can get into it, run specific set of commands inside the console and exit from it.
Now I want to write a bash script that connects to an interactive shell console and runs my commands silently, exits at the end without any interaction. This means I want to have everything automated in a non-interactive way. Any ideas how can I achieve this?
I am trying something like, say, blabla shell is the interactive console here, it always bring me to the interactive mode :(
/usr/bin/blabla shell << EOF
do A,
do B,
do C
quit
EOF
I have a long/specific version of this question can be found here ->
Configure flume in shell/bash script - avoid interactive flume shell console
Closing stdin should do the trick:
exec <&-
The expect command if your friend. It can emulate interactive communication with other commands even in very sophisticated way.
From man expect:
Expect is a program that "talks" to other interactive programs according to a script.
You can try putting the commands you would input in the interactive prompt into a file, then run the command like:
command < file
Maybe the Secure SHell, ssh does what you need. It requires that the "remote" machine is configured as an SSH server. I use it regularly to run commands on other hosts, such as
ssh user#host command
my bash script reads in a few variables and then runs airodump on my home network. I would like to keep the window with airodump running and open some new terminals to run other commands for network discovery while the airodump screen is open (so i can see the results).
right now what i have looks like this (edited for brevity):
#!/bin/bash
read -p "Enter the channel: $channel"
airomon-ng start wlan0 $channel,$channel
airodump-ng -c $channel,$channel mon0 &&
terminator -e netstat -ax &&
terminator -e nmap 192.168.1.1
the first command that uses the whole terminal (airodump) starts up fine and i can see the network, but then it just stays on that screen. If i ctrl+c then it goes back to prompt but i can see the error : Usage: terminator [options] error no such option
i want the netstat and nmap commands to appear and stay in their own terminal windows, how can i do this?
The terminal window is generated by a separate program from the command running inside. Try one of these variations:
xterm -e airomon-start wlan0 "$channel","$channel" &
gnome-terminal -x airomon-start wlan0 "$channel","$channel" &
konsole -e airomon-start wlan0 "$channel","$channel" &
Pick the command that invokes the terminal program you like. You'll have to do this for every command that you want run in its own window. Also, you need to use a single & at the end of each such command line -- not a double && -- those do totally different things. And the last line of your script should be just
wait
that makes it not exit out from under all the terminals, possibly causing them all to die.
Obligatory tangential shell-scripting nitpick: ALWAYS put shell variable uses inside double quotes, unless you know for a fact that you need word-splitting to happen on a particular use.
If the script is running in the foreground in the terminal, then it will pause while an interactive command is using the terminal. You could change the script to run airodump in a new terminal as well, or you could run the background commands before you start airodump (maybe after sleeping, if you're concerned they won't work right if run first?)
I do a fair bit of work at the command line. When I start my computer up on of the first things I do is open up a terminal window for mysql, and one for the Rails console and usually a third running mongrel. Setting it up every morning is a bit of a drag so I would like to script it. How can I open a terminal window, log into mysql, select my development database and then leave it there at the mysql prompt waiting for me. I know how to execute a mysql statement from bash, I just don't know how to get it to leave the prompt open for me to work with after.
Hopefully that is clear!
Update:
Combining the two answers below got things working for mysql. Thanks!
Now I am trying to get a gnome-terminal window to stay open running the Rails script/server command so I can watch the output. For some reason the following closes almost immediately:
gnome-terminal -e "ruby /home/mike/projects/myapp/script/server" &
xterm provides an option for executing a command:
xterm -e myCommandToLogIntoMysql &
You can put a sequence of such xterm commands into a shell script.
How can I open a terminal window, log
into mysql, select my development
database and then leave it there at
the mysql prompt waiting for me.
mysql -u user -ppassword -D database_name
Remember not to put space between "-p" and password. Note - this is a bit insecure, as your password is visible in process list so anyone can read it using ps. You can, however, put your MySQL password in ~/.my.cnf file.