Questions Tagged With shell-script

how to define variable in ssh

zwang10 — Thu, 23 Apr 2015 17:12:38 -0400

I need to use ssh to send command to different computers to run programs. Can I define a variable of Directory and program in front of this shell script? Then, I do not need to write them every time?

host_list=("c15-0330-10.ad.mtu.edu" "c15-0330-11.ad.mtu.edu" "c15-0330-12.ad.mtu.edu") # I have multiple programs # program=c("L_1","L_2","L_3") ssh -f "${host_list[0]}" 'set Directory="/home/campus27/zwang10/Desktop/AWRR/program/power/vmodel_1/nprot/K_10"; cd $Directory && nohup Rscript L_1.R> L_1_sh.txt;echo "The job L_1 is finished" |mutt "zwang10@mtu.edu" -s "The job L_1 is finished"'; ssh -f "${host_list[1]}" 'set Directory="/home/campus27/zwang10/Desktop/AWRR/program/power/vmodel_1/nprot/K_10"; cd $Directory && nohup Rscript L_2.R> L_2_sh.txt;echo "The job L_2 is finished" |mutt "zwang10@mtu.edu" -s "The job L_2 is finished"'; ssh -f "${host_list[2]}" 'set Directory="/home/campus27/zwang10/Desktop/AWRR/program/power/vmodel_1/nprot/K_10"; cd $Directory && nohup Rscript L_3.R> L_3_sh.txt;echo "The job L_3 is finished" |mutt "zwang10@mtu.edu" -s "The job L_3 is finished"';

A query?Green Hosting

Frogicap — Tue, 13 Jan 2015 04:35:59 -0500

Fine, I simply purchased a domain-name from domain.com that was irish And understand im on the best way to get it hosted, questioning Understand this is about 4 pages website, would you guys understand where I could get even free hosting or affordable sponsor????

HOW TO USE ALL INODES IN MY SYSTEM

ashokkrishna — Fri, 24 Oct 2014 10:36:39 -0400

MY UBUNTU PC HAS THE FREE INODES I WANT TO USE ALL OF THEM WITH A AUTOMATIC SHELL SCRIPT. HERE ONE THING I DON'T WANT TO CREATE ANY FILE THAT MEANS WITHOUT CREATING ANY FILE I HAVE TO USE ALL FREE INODES IS THERE ANY COMMAND ? OR SCRIPT?

Passing a stream to a bash function

Rocco — Mon, 13 May 2013 17:49:03 -0400

Hello I have a problem, I need to create a BASH function that I can pass a stream to NOT A FILE. Here is the function: function ff() { cat /etc/group | fgrep -f "$1" }; When I run it like so

ff <( echo some_user )

I get an error saying "fgrep: /dev/fd/63: No such file or directory", instead of "some_uer:x:0:"

Much Appreciated!

Is there any website having command line environment of Linux, for practicing commands?

Avian — Wed, 10 Apr 2013 03:41:49 -0400

I was wondering whether I could practice LINUX commands and shell scripting, online, over a website which could provide me an editor to practice them. And I know that probably the easiest thing to do would be to download a Linux LIVE CD and then practice shell scripting, but apart from it, I want to practice them online, anywhere I want, anytime I want and on any system, without bothering about booting from a LIVE CD. Thanks.

Is there any shell script or software available to watch a CSV file?

tanveer — Wed, 18 Jul 2012 03:23:26 -0400

I am using CentOS 5.5. There is a CSV file in a particular directory(/somewhere/somefile.csv) where a software continuously appending comma separated row(s) of data time to time and the file size is growing big (currently it's 50MB+).

My idea is to create a demon to watch the CSV file. Whenever any row(s) of data appended in that CSV file the demon will read the last appended row(s) and create/write it in a separate text file by date.

I would like to know:

Is there any shell script/software available on this regards to watch a CSV file?
Is there any better idea or solutions other then create a demon?

I have googled tons of time but didn't find any good idea/solution(s). Please help.

Thanks in advance.

Logging bash scripts

Guna — Tue, 02 Aug 2011 05:55:54 -0400

Hi all,

Is there an efficient way to log all the commands being executed from a shell script?

For example if I have in my script:

  firstLoop=$(losetup -f)
  losetup $firstLoop $my_vol

is there a way to automatically log the command (may be by 'set'ting some options) being executed and the result from the command into a log file. Currently I am performing it by passing the command to a shell function, log the command+arguments into a log file and execute the command from the command line by 'tee'ing it into the log file. I have given the function below:

ExecuteCommand(){
  retVal=0
  # LogMessage is  another function that writes the given string into the log file
  LogMessage "-------------- Command Start ------------------------------------------------"
  LogMessage "Command = $*"
  # Execute the command so that the output(and error) is redirected both to the stdout and
  # the logfile
  "$@" 2>&1 | tee -a ${logFile}
  for curr_ret_status in ${PIPESTATUS[@]}
  do
    retVal=${curr_ret_status}
    # Break the loop if it is not a success
    [[ $retVal -ne 0 ]] && break
  done
  LogMessage "Return code is ${retVal}"
  LogMessage "-------------- Command End --------------------------------------------------"
  return $retVal
}

With this approach my example script given above will become:

  firstLoop=$(ExecuteCommand losetup -f)
  ExecuteCommand losetup $firstLoop $my_vol

Do I have to perform what I want only by this way? Or is there a standard efficient way to do this?

Please let me know if you need more information in this regard.

Thanks

Scripting question regarding cut and/or awk

Andy — Mon, 20 Sep 2010 01:28:12 -0400

I'm running into a slight quandary with this particular script I need. I have a used egrep to yank from a large number of config files the location parameter of various unity databases. I have that information in a script. For example, the data looks like:

/home/test/demo/new
/home/test/demo/old
/home/yikes/mydir/ss/new
/home/yikes/mydir/ss/old

So, the problem is each location doesn't have a particular field I can cut with "/" as the delimiter, however, the second to last field in that string is what I want: demo and ss. Is there an easy way to script this. I want to basically spin through this flat file (290 lines), in a new file print out the complete path and then on the same line separated by a space the second to last field.

The end result would look like:

/home/test/demo/new demo
/home/test/demo/old demo
/home/yikes/mydir/ss/new ss
/home/yikes/mydir/ss/old ss

Thanks for the help!