I'd like to use lftp in the beginning of a bash script, but how do I exit lftp without stopping the script from processing? I've tried ending the lftp part with "exit", "quit", and "bye", but they all stop the script.
Previously, I split into two scripts and cron'ed them to run in the right order. Is it possible to combine them into one script?
Or more explicitly, use << EOF.
e.g.
#!/bin/bash
#CMP 01.04.2013
#
#<<EOF below is the functional equivalent of hitting .Enter. on your keyboard.
#It allows the rest of the commands to be executed once connected
lftp -e 'mirror -R /home/pi/LocalDirToMirror ~/TargetDir' -u YourUsername,YourPassword ftp://FTP_URL_Location <<EOF
quit 0
EOF
End the LFTP part of the script with EOF, on its own line. That's all you need to do!
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 a text file in which I have a list of servers. I'm trying to read the server one by one from the file, SSH in the server and execute ls to see the directory contents. My loop runs just once when I run the SSH command, however, for SCP it runs for all servers in the text file and exits, I want the loop to run till the end of text file for SSH. Following is my bash script, how can I make it run for all the servers in the text file while doing SSH?
#!/bin/bash
while read line
do
name=$line
ssh abc_def#$line "hostname; ls;"
# scp /home/zahaib/nodes/fpl_* abc_def#$line:/home/abc_def/
done < $1
I run the script as $ ./script.sh hostnames.txt
The problem with this code is that ssh starts reading data from stdin, which you intended for read line. You can tell ssh to read from something else instead, like /dev/null, to avoid eating all the other hostnames.
#!/bin/bash
while read line
do
ssh abc_def#"$line" "hostname; ls;" < /dev/null
done < "$1"
A little more direct is to use the -n flag, which tells ssh not to read from standard input.
Change your loop to a for loop:
for server in $(cat hostnames.txt); do
# do your stuff here
done
It's not parallel ssh but it works.
I open-sourced a command line tool called Overcast to make this sort of thing easier.
First you import your servers:
overcast import server.01 --ip=1.1.1.1 --ssh-key=/path/to/key
overcast import server.02 --ip=1.1.1.2 --ssh-key=/path/to/key
Once that's done you can run commands across them using wildcards, like so:
overcast run server.* hostname "ls -Al" ./scriptfile
overcast push server.* /home/zahaib/nodes/fpl_* /home/abc_def/
I have a rake task that runs, quite a lot of code. At the end, I need to use sftp and ssh to do some stuff. At the moment I'm unable to automate it. Is there a way to pass to stdout?
This seems like a simple question but I can't find the answer anywhere
#some ruby code
#more ruby code
sh "sftp myuser#hots" #this opens the sftp console
sh "put file" #this doesn't get run until sftp is exited
sh "put another_file" #neither does this
#more ruby code
sh "ssh host" # opens the ssh console
sh "some_action_on_host" # this doesn't get run until ssh is exited
I know there will be ways of doing sftp and ssh using ruby but ideally I just want to be able to pipe variables and commands into the console
So you want to run sftp and send a series of commands to it? How about something like:
sftp = IO.popen("sftp myuser#hots", "w+")
sftp << "put file\n"
sftp << "put another file\n"
sftp.flush # make sure to include this
If you don't want to use ruby, then you may want to enclose your shell commands into ` (backtick characters). This string will be passed to Kernel.` method. This method execute the text as an OS shell command and returns the command's output as a string, e.g.:
`ls`
Alternative syntax to ` is %x[]. This way you can write any bash script:
%x[sftp myuser#hots <<COMMAND
put #{file}
quit
COMMAND]
Please note that this syntax support ruby expressions interpolation using #{...} syntax (similar to double-quoted string literals).
For some reasom I can't get the last line to work. It leaves me at the lftp user#server.org:~> prompt. Any advice?
#!/bin/bash
echo "This will sync the background_docs folder"
lftp ftp://user:pass#server
mirror -r background_docs --only-missing -e
I am guessing you want lftp to run that last line,
mirror -r background_docs --only-missing -e
right?
If so, you must tell it to do so. As it is written, your script simply launches lftp, waits for it to finish, and only then it would attempt to execute the last line.
What you probably want instead is to use lftp's -e cmd option, as such:
#!/bin/bash
echo "This will sync the background_docs folder"
lftp -e "mirror -r background_docs --only-missing -e" ftp://user:pass#server
You've written a shell script. Every line gets executed as a new command at the shell. When you hit ^D to close lftp, it will then try to run the mirror command. (Which might even exist on your system.)
If you want to send commands to a program this way, take a look at the expect(1) tool. There's even a learning mode available (which has given me better success than hand-written expect scripts).
But perhaps your lftp(1) command can be handled with command line parameters instead? That would be more reliable.
I want to start a script remotely via ssh like this:
ssh user#remote.org -t 'cd my/dir && ./myscript data my#email.com'
The script does various things which work fine until it comes to a line with nohup:
nohup time ./myprog $1 >my.log && mutt -a ${1%.*}/`basename $1` -a ${1%.*}/`basename ${1%.*}`.plt $2 < my.log 2>&1 &
it is supposed to do start the program myprog, pipe its output to mylog and send an email with some datafiles created by myprog as attachment and the log as body. Though when the script reaches this line, ssh outputs:
Connection to remote.org closed.
What is the problem here?
Thanks for any help
Your command runs a pipeline of processes in the background, so the calling script will exit straight away (or very soon afterwards). This will cause ssh to close the connection. That in turn will cause a SIGHUP to be sent to any process attached to the terminal that the -t option caused to be created.
Your time ./myprog process is protected by a nohup, so it should carry on running. But your mutt isn't, and that is likely to be the issue here. I suggest you change your command line to:
nohup sh -c "time ./myprog $1 >my.log && mutt -a ${1%.*}/`basename $1` -a ${1%.*}/`basename ${1%.*}`.plt $2 < my.log 2>&1 " &
so the entire pipeline gets protected. (If that doesn't fix it it may be necessary to do something with file descriptors - for instance mutt may have other issues with the terminal not being around - or the quoting may need tweaking depending on the parameters - but give that a try for now...)
This answer may be helpful. In summary, to achieve the desired effect, you have to do the following things:
Redirect all I/O on the remote nohup'ed command
Tell your local SSH command to exit as soon as it's done starting the remote process(es).
Quoting the answer I already mentioned, in turn quoting wikipedia:
Nohuping backgrounded jobs is for example useful when logged in via SSH, since backgrounded jobs can cause the shell to hang on logout due to a race condition [2]. This problem can also be overcome by redirecting all three I/O streams:
nohup myprogram > foo.out 2> foo.err < /dev/null &
UPDATE
I've just had success with this pattern:
ssh -f user#host 'sh -c "( (nohup command-to-nohup 2>&1 >output.file </dev/null) & )"'
Managed to solve this for a use case where I need to start backgrounded scripts remotely via ssh using a technique similar to other answers here, but in a way I feel is more simple and clean (at least, it makes my code shorter and -- I believe -- better-looking), by explicitly closing all three streams using the stream-close redirection syntax (as discussed at the following locations:
https://unix.stackexchange.com/questions/131801/closing-a-file-descriptor-vs
https://unix.stackexchange.com/questions/70963/difference-between-2-2-dev-null-dev-null-and-dev-null-21
http://www.tldp.org/LDP/abs/html/io-redirection.html#CFD
https://www.gnu.org/software/bash/manual/html_node/Redirections.html
Rather than the more widely used but (IMHO) hackier "redirect to/from /dev/null", resulting in the deceptively simple:
nohup script.sh >&- 2>&- <&-&
2>&1 works just as well as 2>&-, but I feel the latter is ever-so-slightly more clear. ;) Most people might have a space preceding the final "background job" ampersand, but since it is not required (as the ampersand itself functions like a semicolon in normal usage), I prefer to omit it. :)