Execute a command with a timeout

2010-12-29 1 min read Bash Learning
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Execute a command with a timeout

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      &nbsp;timelimit -t100 somecommand
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I found this in Ubuntu repos, and consider it better than timeout.

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write the output of a command to /var/log/user.log… each line will contain $USER, making this easy to grep for.

2010-12-28 2 min read Bash Learning Linux

write the output of a command to /var/log/user.log… each line will contain $USER, making this easy to grep for.

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      &nbsp;log() { (echo "$ $@";$@) | logger -t $USER; }
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This command is useful if you want to copy the output of a series of commands to a file, for example if you want to pastebin the output from ‘uname -a’, ‘lspci -vvv’ and ‘lsmod’ for video driver trouble-shooting on your favorite Linux forum.

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Bash Script Beautifier

2010-12-23 1 min read Bash Learning Linux
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Today I was working on a bash script written by someone else. And the script was maintained since long and had actually become quite big and there was no indentation followed. So, you can understand how difficult it was to understand the script. So, I set my foot forth to first find a beautifier for the bash script before I fixed it and my search ended here.

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Take a screenshot of the window the user clicks on and name the file the same as the window title

2010-12-19 2 min read Bash Learning Photo

Take a screenshot of the window the user clicks on and name the file the same as the window title

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      &nbsp;sleep 4; xwd >foo.xwd; mv foo.xwd "$(dd skip=100 if=foo.xwd bs=1 count=256 2>/dev/null | egrep -ao '^[[:print:]]+' | tr / :).xwd"
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In general, this is actually not better than the “scrot -d4” command I’m listing it as an alternative to, so please don’t vote it down for that. I’m adding this command because xwd (X window dumper) comes with X11, so it is already installed on your machine, whereas scrot probably is not. I’ve found xwd handy on boxen that I don’t want to (or am not allowed to) install packages on.

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The Hidden PS

2010-11-27 2 min read Bash Linux
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      &nbsp;for p in `ps L|cut -d' ' -f1`;do echo -e "`tput clear;read -p$p -n1 p`";ps wwo pid:6,user:8,comm:10,$p kpid -A;done
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While going through the source code for the well known ps command, I read about some interesting things.. Namely, that there are a bunch of different fields that ps can try and enumerate for you. These are fields I was not able to find in the man pages, documentation, only in the source.

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Make any command read line enabled (on *nix)

2010-11-25 1 min read Bash Fedora Linux

Make any command read line enabled (on *nix)

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      rlwrap sqlite3 database.db
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Enable readline even if the command line application is not using it.

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commandlinefu.com

by David Winterbottom (codeinthehole.com)

URL: http://feedproxy.google.com/~r/Command-line-fu/~3/mKEgYoyHCMA/make-any-command-read-line-enabled-on-nix

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intercept stdout/stderr of another process or disowned process

2010-11-23 1 min read Bash Fedora Linux

The command is definately going to save your day if you have disowned the process by mistake. Only uses strace so might as well work on Solaris also, though not tried it.

intercept stdout/stderr of another process or disowned process

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      strace -e write=1,2 -p $PID 2>&1 | sed -un "/^ |/p" | sed -ue "s/^.{9 }(.{50}).+/1/g" -e 's/ //g' | xxd -r -p
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Useful to recover a output(stdout and stderr) “disown”ed or “nohup“ep process of other instance of ssh.

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