All commands (14,187)

  • will show: installed linux headers, image, or modules: /^ii/!d avoiding current kernel: /'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)/\1/")"'/d only application names: s/^[^ ]* [^ ]* \([^ ]*\).*/\1/ avoiding stuff without a version number: /[0-9]/!d Show Sample Output


    4
    dpkg -l 'linux-*' | sed '/^ii/!d;/'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)/\1/")"'/d;s/^[^ ]* [^ ]* \([^ ]*\).*/\1/;/[0-9]/!d'
    plasticdoc · 2009-06-19 10:23:38 8
  • will purge: only installed apps: /^ii/!d avoiding current kernel stuff: /'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)/\1/")"'/d using app names: s/^[^ ]* [^ ]* \([^ ]*\).*/\1/ avoiding stuff without a version number: /[0-9]/!d


    7
    dpkg -l 'linux-*' | sed '/^ii/!d;/'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)/\1/")"'/d;s/^[^ ]* [^ ]* \([^ ]*\).*/\1/;/[0-9]/!d' | xargs sudo apt-get -y purge
    plasticdoc · 2009-06-19 10:11:00 9
  • This commands will make it easier to select only common items between two files being compared. If your lines start with things other than lowercase a-z, adjust this Regex appropriately. Number of lines in the output has been set to no more than 10000, and should be adjusted as needed.


    -1
    gdiff --unified=10000 input.file1 inpute.file2 | egrep -v "(^\+[a-z]|^\-[a-z])"| sort > outputfile.sorted
    slashdot · 2009-06-18 20:35:00 8
  • Stuck behind a restrictive firewall at work, but really jonesing to putty home to your linux box for some colossal cave? Goodness knows I was...but the firewall at work blocked all outbound connections except for ports 80 and 443. (Those were wide open for outbound connections.) So now I putty over port 443 and have my linux box redirect it to port 22 (the SSH port) before it routes it internally. So, my specific command would be: iptables -t nat -A PREROUTING -p tcp --dport 443 -j REDIRECT --to-ports 22 Note that I use -A to append this command to the end of the chain. You could replace that with -I to insert it at the beginning (or at a specific rulenum). My linux box is running slackware, with a kernel from circa 2001. Hopefully the mechanics of iptables haven't changed since then. The command is untested under any other distros or less outdated kernels. Of course, the command should be easy enough to adapt to whatever service on your linux box you're trying to reach by changing the numbers (and possibly changing tcp to udp, or whatever). Between putty and psftp, however, I'm good to go for hours of time-killing.


    10
    iptables -t nat -A PREROUTING -p tcp --dport [port of your choosing] -j REDIRECT --to-ports 22
    brizznown · 2009-06-18 17:38:59 11
  • additionally use "find /etc/cron*" for cronscripts Show Sample Output


    1
    cut -d: -f1 /etc/passwd | grep -vE "#" | xargs -i{} crontab -u {} -l
    hoberion · 2009-06-18 16:49:52 9
  • Sometimes you're trying to read through an xml file to determine whats wrong with it and a tool had removed all the linebreaks. xmllint will go ahead and make it pretty for you.


    4
    xmllint --format <filename> > <output file>
    topperge · 2009-06-18 15:00:30 6

  • 0
    shred -vzu /tmp/junk-file-to-be-shredded
    mpb · 2009-06-18 12:00:19 11
  • imports a public key from the web. I know this by head.. but useful nevertheless Show Sample Output


    2
    curl -s http://defekt.nl/~jelle/pubkey.asc | gpg --import
    wires · 2009-06-18 11:26:03 9
  • Appended to grub boot parameters ... gives shell ... password recovery


    2
    init=/bin/bash; mount -o remount,rw /
    m03hr3 · 2009-06-18 08:51:24 6
  • I had some trouble removing empty lines from a file (perhaps due to utf-8, as it's the source of all evil), \W did the trick eventually.


    0
    grep -v "^\W$" <filename>
    nikc · 2009-06-18 08:17:22 17

  • 2
    find directory -size +nnn
    miccaman · 2009-06-18 06:55:00 6

  • 1
    ls -s | sort -nr | more
    miccaman · 2009-06-18 06:44:01 29
  • Starts midnightcommander and allows you to detach the console; use ctrl-\ to detach Then at a later time you can reconnect using dtach -a /tmp/wires-mc In my experience dtach works much better for programs like irssi, mutt, mc, aptitude than screen does.


    5
    dtach -c /tmp/wires-mc mc
    wires · 2009-06-17 22:18:25 12
  • search the newest *.jpg in the directory an make a copy to newest.jpg. Just change the extension to search other files. This is usefull eg. if your webcam saves all pictures in a folder and you like the put the last one on your homepage. This works even in a directory with 10000 pictures.


    1
    cp `ls -x1tr *.jpg | tail -n 1` newest.jpg
    Psychodad · 2009-06-17 20:32:04 9
  • Using the grep command, retrieve all lines from any log files in /var/log/ that have one of the problem states


    6
    grep -2 -iIr "err\|warn\|fail\|crit" /var/log/*
    miketheman · 2009-06-17 19:41:04 10
  • This will create a 10 MB file named testfile.txt. Change the count parameter to change the size of the file. As one commenter pointed out, yes /dev/random can be used, but the content doesn't matter if you just need a file of a specific size for testing purposes, which is why I used /dev/zero. The file size is what matters, not the content. It's 10 MB either way. "Random" just referred to "any file - content not specific" Show Sample Output


    1
    dd if=/dev/zero of=testfile.txt bs=1M count=10
    mstoecker · 2009-06-17 17:06:16 14

  • 2
    qlook() { qlmanage -p "$@" >& /dev/null & }
    mikedamage · 2009-06-17 16:02:34 5

  • 7
    pbpaste > newfile.txt
    mikedamage · 2009-06-17 15:14:22 8
  • Makes any files in the current directory (and any sub-directories) group-readable. Using the "! -perm /g=r" limits the number of files to only those that do not already have this property Using "+" on the end of the -exec body tells find to build the entire command by appending all matching files before execution, so invokes chmod once only, not once per file.


    3
    find . -type f ! -perm /g=r -exec chmod g+r {} +
    sanmiguel · 2009-06-17 13:39:59 5
  • Makes it easy to add keys to new ppa sources entries in apt sources.list Now to add the key for the chromium-daily ppa: launchpadkey 4E5E17B5 Show Sample Output


    9
    alias launchpadkey="sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys"
    azeey · 2009-06-17 12:02:27 10
  • Useful if you have to put together multiple files into one and they are scattered across subdirectories. For example: You need to combine all .sql files into one .sql file that would be sent to DBAs as a batch script. You do get a warning if you create a file by the same extension as the ones your searching for. find . -type f -name *.sql -exec cat {} > BatchFile.txt \;


    4
    find . -type f -name *.ext -exec cat {} > file.txt \;
    realgt · 2009-06-17 11:33:14 15
  • There are two ways to use "here documents" with bash to fill stdin: The following example shows use with the "bc" command. a) Using a delimiter at the end of data: less-than less-than eeooff bc > k=1024 > m=k*k > g=k*m > g > eeooff 1073741824 b) using the "inline" verion with three less-than symbols: less-than less-than less-than "k=1024; m=k*k; g=k*m; g" bc 1073741824 One nice advantage of using the triple less-than version is that the command can easily be recalled from command line history and re-executed. PS: in this "description", I had to use the name "less-than" to represent the less-than symbol because the commandlinefu input text box seems to eat up the real less-than symbols. Odd. Show Sample Output


    9
    <<<"k=1024; m=k*k; g=k*m; g" bc
    mpb · 2009-06-17 10:35:10 12
  • You need sysstat and gawk for this to work. Show Sample Output


    0
    for x in `seq -w 1 30`; do sar -b -f /var/log/sa/sa$x | gawk '/Average/ {print $2}'; done
    unixmonkey4319 · 2009-06-17 02:46:52 4
  • This set of commands was very convenient for me when I was preparing some xml files for typesetting a book. I wanted to check what styles I had to prepare but coudn't remember all tags that I used. This one saved me from error-prone browsing of all my files. It should be also useful if one tries to process xml files with xsl, when using own xml application.


    2
    grep -h -o '<[^/!?][^ >]*' * | sort -u | cut -c2-
    thebodzio · 2009-06-17 00:22:18 10
  • In the above example all files have 4 lines. In "file1" consecutive lines are: "num, 1, 2, 3", in "file2": "name, Jack, Jim, Frank" and in "file3": "scores, 1300, 1100, 980". This one liner can save considerate ammount of time when you're trying to process serious portions of data. "-d" option allows one to set series of characters to be used as separators between data originating from given files. Show Sample Output


    8
    paste -d ',:' file1 file2 file3
    thebodzio · 2009-06-17 00:11:04 12
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worse alternative to
worse alternative to ctrl+r: grep the history removing duplicates without sorting (case insensitive search).

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Download all images from a 4chan thread
Useful for ripping wallpaper from 4chan.org/wg

resume other user's screen session via su, without pty error
Normally, if you su to another user from root and try to resume that other user's screen session, you will get an error like "Cannot open your terminal '/dev/pts/0' - please check." This is because the other user doesn't have permission for root's pty. You can get around this by running a "script" session as the new user, before trying to resume the screen session. Note you will have to execute each of the three commands separately, not all on the same line as shown here. Credit: I found this at http://www.hjackson.org/blog/archives/2008/11/29/cannot-open-your-terminal-dev-pts-please-check.

Download SSL server certificate with opsnessl
Useful when we need to create new certificate for site when current one is near expiry. This downloaded cert can be used to provide organisational data directly to new cert. using below command. e.g. openssl x509 -x509toreq -in /tmp/example.com.cert -out example.com.csr -signkey example.com-key.pem

ssh to machine behind shared NAT
Useful to get network access to a machine behind shared IP NAT. Assumes you have an accessible jump host and physical console or drac/ilo/lom etc access to run the command. Run the command on the host behind NAT then ssh connect to your jump host on port 2222. That connection to the jump host will be forwarded to the hidden machine. Note: Some older versions of ssh do not acknowledge the bind address (0.0.0.0 in the example) and will only listen on the loopback address.

Get your external IP address without curl
Curl is not installed by default on many common distros anymore. wget always is :) $ wget -qO- ifconfig.me/ip

processes per user counter
No need for sort

Copy one file to multiple files
Copies file.org to file.copy1 ... file.copyn

power off system in X hours form the current time, here X=2


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