General :: SSH Command Mode - Flow Of Execution Returns To Bash Shell
Aug 13, 2009
I want to use ssh to execute a command and to wait endlessly to log everything (in file) that comes as a stream of the connected server. But unfortunately, in the manual its written "If command is specified, it is executed on the remote host instead of a login shell"
So what happens is that when I specify my command:
ssh user@server "my_command"
It executed the command and the flow of execution returns to bash shell. So basically my session ends right after the command is executed. This happens only in case I specify command in the command line. If I login into ssh manually and then type "my_command", then the session doesn't end. I want the ssh not to exit, because after "my_command" executes, I want to capture everything in the session.
Now my script is able to start server, But I am still have some problem with my script. When the start server command is executed, the control does not pass the line and does not execute further of that line.what is the problem and how can I get smooth execution of the my script. My Script:
Bash's command history is great, especially it is useful when adding the history -a command to the COMMAND_PROMPT.However, I'm wondering if there is a way to log the commands to a file as soon as the Return key is pressed, e.g. before starting the command and not on completion of the command (using the COMMAND_PROMPT option would save the command once the prompt is there again).
I read about auditing programs like snoopy and session recorder like script but I thought they're already too complex for the simple question I have. I guess that deactivating that script logs all the output of the command would lead already in the right direction but isn't there a quicker way to solve that probelm?
Two processes are communicating through a pipe: A | B. A is writing data faster than B is reading it in. Is there any way to have A limit its writing rate to match B's reading rate?
AFAIK the pipe will get full, and will make A's writing block, waiting for B to read in more data. But is there a way to limit A's writing rate before the pipe fills up? (In a way it's like having a pipe with a really small capacity, but as far as I know pipe capacity is a constant compiled into the kernel.)
Code:
EXAMPLE FOR CLARIFICATION
Right now the command is printing out the following in 1-second intervals:
But with flow control it should print out (again in 1-second intervals):
...since "date" would block on the writing loop due to the slow reading loop.
I am unable to use clear or cls command on bash shell. I have recently installed Cygwin and am using that for practicing unix commands.
I see that I can use Ctrl + L to clear the screen. I created an alias in my .bashrc to do the same as alias cls='^L'
This is how i defined other aliases e.g.
And they work. Hence I assume cls will work too but this is what I get when I try to give cls on command prompt. Am i missing something? Is there a way to do this?
Then someone suggested, You cannot alias keystrokes to commands or vice versa. You could just alias cls to an echo command: echo -en "x0c"
And I added the following to .bashrc,
Sourced the .bashrc file. No errors but cls still does not clear the screen. Infact when I typed the echo -en "x0c on command prompt as well, nothing happened. What does this command do?
Cis 140 student.how to use the test command to evaluate whether the shell variable I create contains a referance to the bash shell? and use the echo command to determine the result.
I want to show line numbers automatically in bash scripts (a habit of being a programmer) and when I load an emacs lisp file it works from the command below but the following command that sets up the same thing for bash scripts doesn't work. I played around with this for quite some time and couldn't find anything that would make work.This is the first time I have tried to customize emacs so it could easily be something ignorant on my part.
i need to take the backup some folders encryption formate with password i used gpg encription in the script but it is not taking the password it throos errorthe syntax is#!/bin/bashtar -cvzf test.tar.gz target ; echo "test" | gpg -c test.tar.gz --stdin
I could run the script from terminal. My script invokes some installation and works fine.But my wish is that end-user should double click the sh script and it should run.But how? I got few links - but none was of was quite helpful
I am working on a build-test system of a set of codes. The system (large enough) is such that one shell script does some work and calls another shell script. This inturn calls a third shell script and so on. How to get the list of all such shell scripts according to the way they are called.? More like a shell script flow tree?
Up until now I've been using plink to remotely compile a project I'm working on. But recently the administrator from the remote server updated the distribution and messed up some configurations. My project has a lot of scripts written for tc shell (tcsh), and now the default shell is bash. There is no way to change this. Another problem is that now I need to run newgrp to change my default user group.
So... to work around this problem I've changed my .bashrc to run newgrp and then tcsh. If I do a normal connection using SSH, everything works as expected, but when using plink, or SSH to remotely execute commands, the shell gets stuck on the newgrp command. I think it's because both applications need a return value from newgrp to send the command I need to execute. Remotely running scripts that call a shell also get stuck like newgrp (newgrp also opens a new shell and that's why it gets stuck) my .bashrc is as follows:
Code:
user_grp=`id -g` if [ $user_grp != 4919 ]; then newgrp new_group_id else
I have a script which builds a project and then runs junit tests. However, if the build fails, the junit tests fail with the same error message.Therefore the command which runs the junit tests should only be executed if the build was successful.
I have seen command like $rm aa dd cc bb ee then something like $ >> zz // it removes zz also Where aa dd cc bb ee zz are the files in my directory. Do not know exactly.
I'm used to being able to put a script in ~/bin and having it overrule the system version of a command. However for "time" or "kill" since the bash shell implements a version of the command (i.e. /bin/ version is not used) doing this is not enough. How can I get the shell to run my own version instead of the version in the shell.I understand the implications of doing this. I know what I'm doing, I can always /bin/whatever if I want to get the old version (or just chmod -x ~/bin/whatever).
I use the time command to measure the wall-clock time of a GPU implementation of an algorithm. When I time the CPU execution of the algorithm time returns a negligible sys time. However, when I time the GPU execution time returns a sys time that is around 20-30% of the total time. If that time was comparable with the negligible sys time of the CPU I would achieve a speedup of a few times higher.
I suspect that the increased sys time is because of the GPU usage, which, I assume, takes some time for the OS because of the drivers etc. I am not sure though, and it is important to figure this out because it will improve my results a lot if I can ignore the sys time and use just the user time for speedup calculations. Also, is there a way to see, in detail, what is the sys running and takes so much time. I am thinking that I might be able to see if it is the driver indeed that causes this delay.
I wonder if there is anyway to make a user-defined bash shell function global, meaning the function can be use in any bash shell scripts, interactively or not. This is what I attempted:
I am trying to fix a perl script, and I really suck at perl. But I think this problem will be easy for people who know it.
The problem is, I have an old setup script someone wrote many years ago. It fails if the standard shell is dash and not bash. The only way I've gotten it to work is to point /bin/sh to bash. I looked thru the script and it uses "system" many places, and I think that's the problem.
I searched for it and found this link:url
My plan is to include this function:
Code: sub system_bash { my @args = ( "bash", "-c", shift ); system(@args); } Then I could simply change all calls to system into system_bash and it should work?
The parameter to the system calls is usually some variable. What if the parameter is a list already? Do I need to test for it somehow, and if it's a list, prepend "bash" and "-c" to the list? How do I do that?
In the script there are lots of places like this:
my $error = system($cmd); if ($error) { die/warn "some error message"; }
Shouldn't there be a return in the system_bash function?
Trying to create a small script that will read user's input, test if user entered some input and if not display some message or display a text using user's input.
The script is the following but i get an error saying "[: 6: =: argument expected"
Do you know how to write a shell script that executes say 4 instances of the same program in different directories at the same time, and once ONE instance completes it executes a new instance of that program in a new directoryd so on, until 100 instances have been executed, each in their own directory
I create a bash script that writes another bash file. But in the generated bash file I want to write a bash command in the file and not executing it.Here's my bash file:
Code: #!/bin/bash cat > ~/generateGridmix2data.sh << END
What options should I use when I'm using the sort command to sort the top 5 CPU processes (ps -eo user,pid,ppid,%cpu,%mem,fname | sort ??? | head -5) showing max to min usage?
Running start_navicat script in kubuntu 11.04 returns bash error ./start_navicat: 10: arithmetic expression: expecting EOF: "2*100+13 2". The same navicat version runs fine in ubuntu 10.10 and 10.04. I tried deleting navicat folders - including hidden folders and reinstalling, but get the same error.Can't test ubuntu 11.04 because i can't get it running (black screen - even grub). xubuntu 11.04 is very unstable too. kubuntu 11.04 is very stable otherwise.no idea what to do, other than continue using ubuntu 10.10 (which is the best ubuntu version to date imho)
