Search Results

Search found 8028 results on 322 pages for 'unix shell'.

Page 49/322 | < Previous Page | 45 46 47 48 49 50 51 52 53 54 55 56  | Next Page >

  • How do I write to a file and print to a terminal cuncurrently in Unix?

    - by bias
    I have a little bash function to log my Macports outputs to a file (since installs often spew little tidbits that are easy to lose in terminal noise), then I just cat the file to the terminal: function porti { command sudo port install $@ >> $1.log 2>&1; cat $1.log } Is there a way to do this concurrently? I don't care about it being in Bash, that's just how I started it. BTW I pass $@ to install but only $1 for the file name so that I can do something like: porti git-gore +bash_completion and only get the file git-core.log however someone else might prefer to include variants in the file name ...

    Read the article

  • Unix: millionth number in the serie 2 3 4 6 9 13 19 28 42 63 ... ?

    - by HH
    It takes about minute to achieve 3000 in my comp but I need to know the millionth number in the serie. The definition is recursive so I cannot see any shortcuts except to calculate everything before the millionth number. How can you fast calculate millionth number in the serie? Serie Def n_{i+1} = \floor{ 3/2 * n_{i} } and n_{0}=2. Interestingly, only one site list the serie according to Goolge: this one. Too slow Bash code #!/bin/bash function serie { n=$( echo "3/2*$n" | bc -l | tr '\n' ' ' | sed -e 's@\\@@g' -e 's@ @@g' ); # bc gives \ at very large numbers, sed-tr for it n=$( echo $n/1 | bc ) #DUMMY FLOOR func } n=2 nth=1 while [ true ]; #$nth -lt 500 ]; do serie $n # n gets new value in the function throught global value echo $nth $n nth=$( echo $nth + 1 | bc ) #n++ done

    Read the article

  • UNIX FIFO: How to allow only one writer/reader pair to use a FIFO?

    - by Max Krug
    Hi! I've written two programs: the first, the "writer", creates a FIFO and writes data into it. The second one, the "reader" runs in background and looks for data in the FIFO. Once data is there, the reader reads it out. If I start e.g. two writers and two readers, they all can write/read into/from the same FIFO. How can I restrict it for 3rd and 4th readers/writers to use the FIFO and allow only one writer and one reader to use the FIFO? thanks a lot. -- kind regards, Max Krug

    Read the article

  • How can I wrap an executable on UNIX (SunOS) so that it is never run more than once at the same time

    - by user332815
    I have an executable (no source) that I need to wrap, to make sure that it is not called more than once at a time. I immediately think of some sort of queue wrapper, but how do I actually make it so that my wrapper is called instead of the executable itself? Is there a better way to do this? The solution needs to be invisible because the users are other applications. Any information/recommendations are appreciated.

    Read the article

  • How do I daemonize an arbitrary script in unix?

    - by dreeves
    I'd like a daemonizer that can turn an arbitrary, generic script or command into a daemon. There are two common cases I'd like to deal with: I have a script that should run forever. If it ever dies (or on reboot), restart it. Don't let there ever be two copies running at once (detect if a copy is already running and don't launch it in that case). I have a simple script or command line command that I'd like to keep executing repeatedly forever (with a short pause between runs). Again, don't allow two copies of the script to ever be running at once. Of course it's trivial to write a "while(true)" loop around the script in case 2 and then apply a solution for case 1, but a more general solution will just solve case 2 directly since that applies to the script in case 1 as well (you may just want a shorter or no pause if the script is not intended to ever die (of course if the script really does never die then the pause doesn't actually matter)). Note that the solution should not involve, say, adding file-locking code or PID recording to the existing scripts. More specifically, I'd like a program "daemonize" that I can run like % daemonize myscript arg1 arg2 or, for example, % daemonize 'echo `date` >> /tmp/times.txt' which would keep a growing list of dates appended to times.txt. (Note that if the argument(s) to daemonize is a script that runs forever as in case 1 above, then daemonize will still do the right thing, restarting it when necessary.) I could then put a command like above in my .login and/or cron it hourly or minutely (depending on how worried I was about it dying unexpectedly). NB: The daemonize script will need to remember the command string it is daemonizing so that if the same command string is daemonized again it does not launch a second copy. Also, the solution should ideally work on both OS X and linux but solutions for one or the other are welcome. (If I'm thinking of this all wrong or there are quick-and-dirty partial solutions, I'd love to hear that too.)

    Read the article

  • how to escape slashes in perl command in unix script?

    - by understack
    end_date=$(date +"%m/%d/%Y") /usr/bin/perl -pi -e "s/_end_date_/${end_date}/g" filename I want to replace string '_end_date_' with current date. Since current date has slashes in it(yes I want the slashes), I need to escape them. How can I do this? I've tried several ways like replacing slashes with "\/" using sed and perl itself but it didn't work. Finally I used 'cut' to break date in 3 parts and escaped slashes but this solution doesn't look good. Any better solution?

    Read the article

  • How can I set a default value when incorrect/invalid input is entered in Unix?

    - by user2889968
    i want to set the value of inputLineNumber to 20. I tried checking if no value is given by user by [[-z "$inputLineNumber"]] and then setting the value by inputLineNumber=20. The code seems to be working correct when no value is given but I also receive ./t.sh: [-z: not found as message on the console. Is there some way to not print this message. Here's my full script as well. #!/bin/sh cat /dev/null>copy.txt echo "Please enter the sentence you want to search:" read "inputVar" echo "Please enter the name of the file in which you want to search:" read "inputFileName" echo "Please enter the number of lines you want to copy:" read "inputLineNumber" [[-z "$inputLineNumber"]] || inputLineNumber=20 cat /dev/null > copy.txt for N in `grep -n $inputVar $inputFileName | cut -d ":" -f1` do LIMIT=`expr $N + $inputLineNumber` sed -n $N,${LIMIT}p $inputFileName >> copy.txt echo "-----------------------" >> copy.txt done cat copy.txt

    Read the article

  • How can I run a Perl program when I don't have ssh or shell access?

    - by Christopher
    I just installed an IRC bot, B****X (Don't ask, I don't know - the real name is not censored). I did all of the configuration and chmod'ed the pl files to 755, but running it won't work. My host does not allow SSH/Shell (which is how the documentation says to runs he script), but just going to the URL usually works because of this. However, I get a 500 (Internal Server Error) error. I have logged errors and you can find them at http://services.cl58tools.co.cc/irc/errors.txt Thanks in advance

    Read the article

  • Specify private SSH-key to use when executing shell command with or without Ruby?

    - by Christoffer
    A rather unusual situation perhaps, but I want to specify a private SSH-key to use when executing a shell (git) command from the local computer. Basically like this: git clone [email protected]:TheUser/TheProject.git -key "/home/christoffer/ssh_keys/theuser" Or even better (in Ruby): with_key("/home/christoffer/ssh_keys/theuser") do sh("git clone [email protected]:TheUser/TheProject.git") end I have seen examples of connecting to a remote server with Net::SSH that uses a specified private key, but this is a local command. Is it possible? Thanks

    Read the article

  • Using cp command in linux shell, how do I copy a whole directory into another directory?

    - by Dmitry Supranovich
    I have a directory, let's say, "work": ~/work/ This directory has some sub-folders (d1, d2...) in it and files in these sub-folders. I want to make a backup copy in the same folder, so it would be like: ~/backup/work/ However, when I use cp -r ./work ./backup the folder "work" is not copied, only its subfoders (so now it's ~/backup/d1 ~/backup/d2...) Any idea how to make it work? I'm quite new to shell, so I'm missing something :)

    Read the article

  • Reliable alert dialogs from the shell

    - by intuited
    I'd like to have a message pop up in response to various system events, mostly in order to be able to set reminders for myself from a shell session. There are a few ways to do this; zenity seems to be the most polished. However, I've found at least two problems with zenity: Messages do not appear on all workspaces. I tried using the gtk option --screen to control this, but they just appear on the current workspace regardless. So if I am switching workspaces as the message comes up, I will not see it. Messages do not appear above all other windows. Specifically, if I am using guake, a new zenity message will appear below the guake window and I won't be able to see it. I tried a few other apps a while back. Both gmessage and xmessage exhibited problem 1; gmessage also exhibited problem 2. I did find that kalarm, which can be scripted from the command line, worked acceptably, but I'm trying to avoid running the KDE stack if possible, and would prefer something lightweight with zenity's versatility. It seems that it might be possible to arrange for these problems to be resolved by setting the WM_CLASS, but I'm in a bit over my head there. It might also be possible to make modifications to the window after it launches with a script, but again I'm not sure where to look for resources on that.

    Read the article

< Previous Page | 45 46 47 48 49 50 51 52 53 54 55 56  | Next Page >