All commands (14,187)

  • This doesn't make any assumptions about your IP address and prints out one IP address per line if you have multiple network interfaces. Show Sample Output


    -3
    ifconfig | sed '/.*addr.*Bcast.*/ ! d'| sed 's/.*addr:\([0-9\.]*\).*/\1/'
    Haegin · 2010-03-26 08:13:13 3
  • This assumes your local ip starts with 192.something (e.g. 192.168), it greps ifconfig output for an ip that starts with 192, then strips the extra garbage (besides the ip) Maybe `ifconfig | grep addr | grep Bcast` would also do it Show Sample Output


    -5
    ifconfig | grep addr:192 | sed s/Bcast.*// | sed 's/^.*inet addr://'
    hasenj · 2010-03-26 07:37:21 4
  • This is useful for examining the path. Show Sample Output


    6
    printf ${PATH//:/\\n}
    haivu · 2010-03-26 04:37:33 5
  • Okay, Jimmy, the command 'optical-monitor' is needed within the global config. for this command to work (and if supported by your licsense: yada yada, blah, blah). But, like its mad PHAT Kid, you dig? Basically, a Foundry/Brocade switch is reading the Laser light levels just like those Fiber test kits from Owl that cost 4k. I know, I also find it hard to contain myeself ;-) No really..... Show Sample Output


    -3
    show optic <slot #>
    rootgeek · 2010-03-26 03:07:22 3
  • You need all those commands, in the sample output. I had some of this, but had to play, add remove, type random stuff like a monkey to finally get this working (clearly those IP's are fake to protect the guilty, and so is the key). Show Sample Output


    -3
    aaa authentication login default local tacacs+
    rootgeek · 2010-03-26 02:58:03 3
  • This is how you make sure that ports in a VLAN remain, root ports. Typically, you would use this command on all your Core-1 switch VLAN ports, and then use 'rstp priority 1' on all your Core-2 switches. This is if you have a dual L3 core that is. Show Sample Output


    -3
    rstp priority 0
    rootgeek · 2010-03-26 02:51:54 3
  • 'no untag' is applied to _all_ ports under the default VLAN. Otherwise the default VLAN runs untagged over all physical ports. Pretty good idea to 'prune' your VLANs and define which ones pass over and across trunks that carry the default VLAN traffic. Show Sample Output


    -3
    no untag
    rootgeek · 2010-03-26 02:45:32 3
  • The sample output, is the command with a ?, to show you all the stuff you can look at. Show Sample Output


    -4
    dm ?
    rootgeek · 2010-03-26 02:42:21 3
  • The sample output, is a display of the values you can change, using this command. After a change of of these settings you will need to reload the box, by typing...wait...wait for IT: 'reload'. This comes in handy when working with the RX hardware, for example, which has a base limitation of 32 (RSTP (802-1w) instances. For all of you paying attention that means if you run RSTP on a RX you can only have 32 VLANs. Sure, you can have common groups of VLANs, like back in the day style MSTP, PVST, PVST+ (and all that old STP (802.1d) mess), before "per vlan spanning-tree", RSTP (802-1w), was made. But who wants to do all that? Show Sample Output


    -2
    system max <some value>
    rootgeek · 2010-03-26 02:39:00 5

  • -4
    sh default values
    rootgeek · 2010-03-26 02:36:57 4
  • Here "^M" is NOT "SHIFT+6" and "M". Type CTRL+V+M to get it instead. Its shortest and easy. And its sed!, which is available by default in all linux flavours.. no need to install extra tools like fromdos.


    4
    sed -i 's/^M//' file
    sata · 2010-03-25 19:34:08 7
  • This is easy to type if you are looking for a few (hundred) "missing" megabytes (and don't mind the occasional K slipping in)... A variation without false positives and also finding gigabytes (but - depending on your keyboard setup - more painful to type): du -hs *|grep -P '^(\d|,)+(M|G)'|sort -n (NOTE: you might want to replace the ',' according to your locale!) Don't forget that you can modify the globbing as needed! (e.g. '.[^\.]* *' to include hidden files and directories (w/ bash)) in its core similar to: http://www.commandlinefu.com/commands/view/706/show-sorted-list-of-files-with-sizes-more-than-1mb-in-the-current-dir Show Sample Output


    3
    du -hs *|grep M|sort -n
    tuxlifan · 2010-03-25 19:20:24 4
  • Finds all C++, Python, SWIG files in your present directory (uses "*" rather than "." to exclude invisibles) and counts how many lines are in them. Returns only the last line (the total). Show Sample Output


    2
    find * \( -name "*.[hc]pp" -or -name "*.py" -or -name "*.i" \) -print0 | xargs -0 wc -l | tail -n 1
    neologism · 2010-03-25 18:58:29 4

  • 2
    ls -d $(echo ${PATH//:/ }) > /dev/null
    ger · 2010-03-25 17:38:57 3
  • Using this command one can cut a piece from the end of an audio file.


    1
    sox input.wav output.wav reverse trim 00:00:00.3 reverse
    bodo · 2010-03-25 13:38:44 3

  • -2
    printf "%.50d" 0 | tr 0 -
    sata · 2010-03-25 12:52:45 3
  • essentially the ruby one, but perhaps has a larger installed base


    9
    python -c 'print "-"*50'
    funky · 2010-03-25 11:09:30 6
  • This feels more intuitive to me.


    1
    for i in `seq 1 1 50`; do echo -n -; done
    Gosha · 2010-03-25 10:22:19 3

  • 5
    svn log -r {`date +"%Y-%m-%d" -d "1 month ago"`}:HEAD|grep '^r[0-9]' |cut -d\| -f2|sort|uniq -c
    ivanatora · 2010-03-25 09:43:15 4
  • Get there by going backwards and forgetting the numbers.


    5
    seq -s" " -50 -1 | tr -dc -
    DoNotRememberMe · 2010-03-25 06:00:24 32
  • If you want to relocate a package on your own, or you just want to know what those PREIN/UN and POSTIN/UN scripts will do, this will dump out all that detail simply. You may want to expand the egrep out other verbose flags like CHANGELOGTEXT etc, as your needs require. It isn't clear, but the formatting around $tag is important: %{$tag} just prints out the first line, while [%{$tag }] iterates thru multi-line output, joining the lines with a space (yes, there's a space between the g and } characters. To break it out for all newlines, use [%{$tag\n}] but the output will be long. This is aside from rpm2cpio | cpio -ivd to extract the package files.


    0
    rpm --querytags | egrep -v HEADERIMMUTABLE | sort | while read tag ; do rpm -q --queryformat "$tag: [%{$tag} ]\n" -p $SomeRPMfile ; done
    DoNotRememberMe · 2010-03-25 05:40:48 3
  • The example is a little bit bogus, but applies to any command that takes a while interactively, or might be a bit of a drag on system resources. Once the command's output is saved to a variable, you can then echo "$OUTPUT" to see it in multi-line glory after that. The use of double-quotes around the backticks and during the variable expansion disables any IFS conversion during those two operations. Very useful for reporting that might pull different lines out, like from dmidecode, inq or any other disk detail command. The only caveat is that storing too much in a variable might make your shell process grow.


    0
    OUTPUT="`find / -type f`" ; echo "$OUTPUT" | grep sysrq ; echo "$OUTPUT" | grep sysctl ; echo "$OUTPUT" | less
    DoNotRememberMe · 2010-03-25 05:02:10 5
  • I had problems in Ubuntu while trying to edit /etc/resolv.conf, even with sudo I couldn't make any change. After a 2 minutes search on google I found this command. Hope someone finds it useful. It works like chmod, with + and - to denote which attributes are being added and which are being removed. See other attributes on man pages or on wikipedia http://en.wikipedia.org/wiki/Chattr


    1
    sudo chattr -i <file that cannot be modified>
    leovailati · 2010-03-25 03:14:34 4

  • 2
    aptitude search '~i!~E' | grep -v "i A" | cut -d " " -f 4
    XORwell · 2010-03-25 00:40:51 6
  • Write a file you edited in Vim but that you do not have the permissions to write to (unless you use sudo.) Same as #1204 but without the echo to stdout that I find annoying.


    32
    :w !sudo tee > /dev/null %
    idemal · 2010-03-24 20:04:26 13
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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" }

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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.

Place the NUM-th argument of the most recent command on the shell
After executing a command with multiple arguments like cp ./temp/test.sh ~/prog/ifdown.sh you can paste any argument of the previous command to the console, like ls -l ALT+1+. is equivalent to ls -l ./temp/test.sh ALT+0+. stands for command itself ('ls' in this case) Simple ALT+. cycles through last arguments of previous commands.

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

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

awk date convert
Convert readable date/time with `date` command

Alias TAIL for automatic smart output
Run the alias command, then issue $ps aux | tail and resize your terminal window (putty/console/hyperterm/xterm/etc) then issue the same command and you'll understand. $ ${LINES:-`tput lines 2>/dev/null||echo -n 12`} Insructs the shell that if LINES is not set or null to use the output from `tput lines` ( ncurses based terminal access ) to get the number of lines in your terminal. But furthermore, in case that doesn't work either, it will default to using the default of 80. The default for TAIL is to output the last 10 lines, this alias changes the default to output the last x lines instead, where x is the number of lines currently displayed on your terminal - 7. The -7 is there so that the top line displayed is the command you ran that used TAIL, ie the prompt. Depending on whether your PS1 and/or PROMPT_COMMAND output more than 1 line (mine is 3) you will want to increase from -2. So with my prompt being the following, I need -7, or - 5 if I only want to display the commandline at the top. ( http://www.askapache.com/linux/bash-power-prompt.html ) 275MB/748MB [7995:7993 - 0:186] 06:26:49 Thu Apr 08 [askapache@n1-backbone5:/dev/pts/0 +1] ~ $ In most shells the LINES variable is created automatically at login and updated when the terminal is resized (28 linux, 23/20 others for SIGWINCH) to contain the number of vertical lines that can fit in your terminal window. Because the alias doesn't hard-code the current LINES but relys on the $LINES variable, this is a dynamic alias that will always work on a tty device.

generate a unique and secure password for every website that you login to
usage: sitepass MaStErPaSsWoRd example.com description: An admittedly excessive amount of hashing, but this will give you a pretty secure password, It also eliminates repeated characters and deletes itself from your command history. tr '!-~' 'P-~!-O' # this bit is rot47, kinda like rot13 but more nerdy rev # this avoids the first few bytes of gzip payload, and the magic bytes.

Route outbound SMTP connections through a addtional IP address rather than your primary


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