All commands (14,184)

  • Felt like I need to win the lottery, and wrote this command so I train and develop my guessing abilities. Show Sample Output


    13
    A=1;B=100;X=0;C=0;N=$[$RANDOM%$B+1];until [ $X -eq $N ];do read -p "N between $A and $B. Guess? " X;C=$(($C+1));A=$(($X<$N?$X:$A));B=$(($X>$N?$X:$B));done;echo "Took you $C tries, Einstein";
    rodolfoap · 2009-12-16 13:24:23 142
  • Check general system error on AIX


    1
    errpt -a | more
    marousan · 2009-12-16 12:07:16 3
  • I wanted to create a copy of my whole laptop disk on an lvm disk of the same size. First I created the logical volume: lvcreate -L120G -nlaptop mylvms SOURCE: dd if=/dev/sda bs=16065b | netcat ip-target 1234 TARGET: nc -l -p 1234 | dd of=/dev/mapper/mylvms-laptop bs=16065b to follow its process you issue the following command in a different terminal STATS: on target in a different terminal: watch -n60 -- kill -USR1 $(pgrep dd) (see http://www.commandlinefu.com/commands/view/4356/output-stats-from-a-running-dd-command-to-see-its-progress)


    7
    SOURCE: dd if=/dev/sda bs=16065b | netcat ip-target 1234 TARGET: netcat -l -p 1234 | dd of=/dev/mapper/laptop bs=16065b STATS on target: watch -n60 -- kill -USR1 $(pgrep dd)
    bw · 2009-12-16 10:51:06 10
  • if you start a large dd and forgot about statistics, but you still wonder what the progress is this command in an OTHER terminal will show you the way. NOTE: the watch command by itself will not output anything NOTE: the kill command will not kill the process Show Sample Output


    2
    watch -n60 --kill -USR1 $(pgrep dd)
    bw · 2009-12-16 10:35:28 4
  • If you give tar a list of filenames, it will not add the directories, so if you don't care about directory ownership or permissions, you can save some space. Tar will create directories as necessary when extracting. This command is limited by the maximum supported size of the argument list, so if you are trying to tar up the whole OS for instance, you may just get "Argument list too long".


    3
    tar -cvzf arch.tgz $(find /path/dir -not -type d)
    pysquared · 2009-12-15 13:46:54 6
  • Tar - Compress by excluding folders Show Sample Output


    -1
    tar -cvf /path/dir.tar /path/dir* --exclude "/path/dir/name" --exclude "/path/dir/opt"
    sandeepverma · 2009-12-15 09:48:41 3

  • 8
    COL=$(( $(tput cols) / 2 )); clear; tput setaf 2; while :; do tput cup $((RANDOM%COL)) $((RANDOM%COL)); printf "%$((RANDOM%COL))s" $((RANDOM%2)); done
    sputnick · 2009-12-15 02:48:28 10
  • This can show all ls colors, with a demo.


    8
    echo $LS_COLORS | sed 's/:/\n/g' | awk -F= '!/^$/{printf("%s \x1b[%smdemo\x1b[0m\n",$0,$2)}'
    bones7456 · 2009-12-15 01:17:46 7
  • We force IPv4, compress the stream, specify the cypher stream to be Blowfish. I suppose you could use aes256-ctr as well for cypher spec. I'm of course leaving out things like master control sessions and such as that may not be available on your shell although that would speed things up as well.


    18
    ssh -4 -C -c blowfish-cbc
    vxbinaca · 2009-12-15 00:30:53 34
  • Not everyone reads manpages. Aliasing this command will help with the task of doing audits with RKhunter. It will check for the latest version, update the definitions and then run a check on the system. Hint: alias that in your .bashrc to make life for your fingers easier.


    2
    rkhunter --versioncheck --update --propupd --check
    vxbinaca · 2009-12-15 00:23:45 4
  • This command is a great way to check to see if acpi is doing damage to your disks by agressivly parking the read arm and wearing down it's life. As you can see, mine has lost half its life. I'm sure this could be shortened though somehow. It will use smartctl to dump the stats and then grep out just the temperature and load cycles for the disk (a load cycle is when a the read arm comes out of park and wears on the drive). Show Sample Output


    2
    watch -d 'sudo smartctl -a /dev/sda | grep Load_Cycle_Count ; sudo smartctl -a /dev/sda | grep Temp'
    vxbinaca · 2009-12-15 00:15:24 5
  • FLAC's built in integrity checks are far more useful then devising a scheme to use MD5 sum files. This will check all the FLAC in a directory and output only errors. Remove the "s" after the "t" and it will be somewhat verbose in the check.


    1
    flac -ts *.flac
    vxbinaca · 2009-12-15 00:07:51 5
  • This command is meant to be used to make a lightweight backup, for when you want to know which files might be missing or changed, but you don't care about their contents (because you have some way to recover them). Explanation of parts: "ls -RFal /" lists all files in and below the root directory, along with their permissions and some other metadata. I think sudo is necessary to allow ls to read the metadata of certain files. "| gzip" compresses the result, from 177 MB to 16 MB in my case. "> all_files_list.txt.gz" saves the result to a file in the current directory called all_files_list.txt.gz. This name can be changed, of course. Show Sample Output


    2
    sudo ls -RFal / | gzip > all_files_list.txt.gz
    roryokane · 2009-12-14 21:40:56 3
  • Remove security from PDF document using this very simple command on Linux and OSX. You need ghostscript for this baby to work.


    47
    gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=OUTPUT.pdf -c .setpdfwrite -f INPUT.pdf
    deijmaster · 2009-12-14 21:30:22 27
  • The above url contains over 6700 of the common ad websites. The command just pastes these into your /etc/hosts. Show Sample Output


    7
    wget -q -O - http://someonewhocares.org/hosts/ | grep ^127 >> /etc/hosts
    torrid · 2009-12-14 17:11:16 8
  • Useful if a different user cannot access some directory and you want to know which directory on the way misses the x bit. Show Sample Output


    2
    dir=$(pwd); while [ ! -z "$dir" ]; do ls -ld "$dir"; dir=${dir%/*}; done; ls -ld /
    hfs · 2009-12-14 14:38:11 3
  • Displays a scrolling banner which loops until you hit Ctrl-C to terminate it. Make sure you finish your banner message with a space so it will loop nicely.


    11
    while [ 1 ]; do banner 'ze missiles, zey are coming! ' | while IFS="\n" read l; do echo "$l"; sleep 0.01; done; done
    craigds · 2009-12-14 07:40:07 10
  • If you want all the URLs from all the sessions, you can use : perl -lne 'print for /url":"\K[^"]+/g' ~/.mozilla/firefox/*/sessionstore.js Thanks to tybalt89 ( idea of the "for" statement ). For perl purists, there's JSON and File::Slurp modules, buts that's not installed by default.


    0
    perl -lne 'print for /url":"\K[^"]+/g' $(ls -t ~/.mozilla/firefox/*/sessionstore.js | sed q)
    sputnick · 2009-12-14 00:51:54 2
  • blue and yellow colored bash prompt for a Hanukkah celebration on your box


    3
    export PS1="\e[0;34m[\u\e[0;34m@\h[\e[0;33m\w\e[0m\e[0m\e[0;34m]#\e[0m "
    decept · 2009-12-13 18:35:06 8
  • This command, taken from play's manual page, plays a synthesized guitar tone for each of the strings on a standard tuned guitar. The command "play" is a part of the package "sox".


    18
    for n in E2 A2 D3 G3 B3 E4;do play -n synth 4 pluck $n repeat 2;done
    eightmillion · 2009-12-13 06:57:26 32

  • 11
    cpan -r
    sputnick · 2009-12-13 02:54:22 9
  • Thanks to comment if that works or not... If you have already typed that snippet or you know you already have IO::Interface::Simple perl module, you can type only the last command : perl -e 'use IO::Interface::Simple; my $ip=IO::Interface::Simple->new($ARGV[0]); print $ip->address,$/;' <INTERFACE> ( The first perl command will install the module if it's not there already... )


    1
    x=IO::Interface::Simple; perl -e 'use '$x';' &>/dev/null || cpan -i "$x"; perl -e 'use '$x'; my $ip='$x'->new($ARGV[0]); print $ip->address,$/;' <INTERFACE>
    sputnick · 2009-12-13 02:23:40 36
  • Knowing when a filesystem is created , you can deduce when an operating system was installed . find filesystem device (/dev/) informations by using the cat /etc/fstab command. Show Sample Output


    7
    dumpe2fs -h /dev/DEVICE | grep 'created'
    eastwind · 2009-12-12 14:47:33 14

  • 4
    du -sch ./*
    enderst · 2009-12-12 05:10:40 3

  • 1
    ffmpeg -i Your_video_file -s 320x240 FILE.flv
    eastwind · 2009-12-12 00:28:10 4
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add all files not under version control to repository
With the force options the same results can be achieved

Get the size of all the directories in current directory (Sorted Human Readable)
This allows the output to be sorted from largest to smallest in human readable format.

Hiding and Show files on Mac OS X
These commands will mark a file as hidden or visible to Mac OS X Finder. Notice the capitol V vs the lowercase v. This will also work for directories. setfile -a V foo.bar; // This marks the file invisible setfile -a v foo.bar; // This marks the file visible I have also found that adding the following aliases are helpful: alias hide='setfile -a V' alias show='setfile -a v'

Mirror a directory structure from websites with an Apache-generated file indexes
wget/curl/friends are not good with mirroring files off websites, especially those with Apache-generated directory listings. These tools endlessly waste time downloading useless index HTML pages. lftp's mirror command does a better job without the mess.

Block the 6700 worst spamhosts
The above url contains over 6700 of the common ad websites. The command just pastes these into your /etc/hosts.

Give any files that don't already have it group read permission under the current folder (recursive)
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.

Optimal way of deleting huge numbers of files
This command works by rsyncing the target directory (containing the files you want to delete) with an empty directory. The '--delete' switch instructs rsync to remove files that are not present in the source directory. Since there are no files there, all the files will be deleted. I'm not clear on why it's faster than 'find -delete', but it is. Benchmarks here: https://web.archive.org/web/20130929001850/http://linuxnote.net/jianingy/en/linux/a-fast-way-to-remove-huge-number-of-files.html

Make vim open in tabs by default (save to .profile)
I always add this to my .profile rc so I can do things like: "vim *.c" and the files are opened in tabs.

Generate a list of items from a couple of items lists A and B, getting (B - A ) set
ItemsListtoAvoid (A) could be a list of files with a special characteristic to exclude. It can be a result of previous processing list, ex. a list of files containing a special string. AlItemsList.txt (B) Is a complete list of items including some or all items in A. $Difference is saved in ItemsDifference.txt

list and sort files by size in reverse order (file size in human readable output)
This command list and sort files by size and in reverse order, the reverse order is very helpful when you have a very long list and wish to have the biggest files at the bottom so you don't have scrool up. The file size info is in human readable output, so ex. 1K..234M...3G Tested with Linux (Red Hat Enterprise Edition)


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