All commands (14,187)

  • Command to build one or more network segments - with for

    Show Sample Output


    0
    seg() { for b in $(echo $1); do for x in $(seq 10); do echo $b.$x; done; done }
    Waldirio · 2009-10-20 18:14:25 3
  • Command to build one or more network segments - with while

    Show Sample Output


    0
    seg() { echo -e "$1" | while read LINE; do for b in $(seq 10); do echo $LINE.$b; done; done; }
    Waldirio · 2009-10-20 17:45:43 3
  • Partition a new disk as all one partition tagged as "LInux LVM"

    This is a bit hacky, but if you're setting up a bunch of new LUNs, it can save a bunch of time. Also check out sfdisk. The fdisk will fail if, for example, a partition table already exists.


    -1
    echo -e "n\np\n1\n\n\nt\n8e\nw" | fdisk /dev/sdX
    sud0er · 2009-10-20 16:21:54 5
  • List system's users


    -12
    teste.txt < cut -d : -f 1,5 /etc/passwd | tr : \\t | tr a-z A-Z | cat teste.txt
    osvaldofilho · 2009-10-20 14:53:38 9
  • Set default "New Page" as HTML in TextMate

    When you press "cmd+n" in TextMate, you can have "HTML" language as default document format... You can also define other languages too. You need to know the UUID of your language bundle.


    -1
    defaults write com.macromates.textmate OakDefaultLanguage 17994EC8-6B1D-11D9-AC3A-000D93589AF6
    vigo · 2009-10-20 07:10:34 4
  • Restore a local drive from the image on remote host via ssh


    2
    ssh user@server 'dd if=sda.img' | dd of=/dev/sda
    newrain7803 · 2009-10-20 06:52:26 3
  • Backup a local drive into a file on the remote host via ssh


    12
    dd if=/dev/sda | ssh user@server 'dd of=sda.img'
    newrain7803 · 2009-10-20 06:47:01 7
  • Compression formats Benchmark

    See: http://imgur.com/JgjK2.png for example. Do some serious benchmarking from the commandline. This will write to a file with the time it took to compress n bytes to the file (increasing by 1). Run: gnuplot -persist <(echo "plot 'lzma' with lines, 'gzip' with lines, 'bzip2' with lines") To see it in graph form.


    3
    for a in bzip2 lzma gzip;do echo -n>$a;for b in $(seq 0 256);do dd if=/dev/zero of=$b.zero bs=$b count=1;c=$(date +%s%N);$a $b.zero;d=$(date +%s%N);total=$(echo $d-$c|bc);echo $total>>$a;rm $b.zero *.bz2 *.lzma *.gz;done;done
    matthewbauer · 2009-10-20 01:00:51 5
  • Quickly Encrypt a file with gnupg and email it with mailx

    This is a quick and easy way of encrypting files in a datastream, without ever really creating an output file from gpg. Useful with cron also, when file(s) have to be sent based on a set schedule.


    3
    cat private-file | gpg2 --encrypt --armor --recipient "Disposable Key" | mailx -s "Email Subject" user@email.com
    slashdot · 2009-10-19 20:38:37 4
  • List your largest installed packages (on Debian/Ubuntu)

    Use the hold space to preserve lines until data is needed.


    -3
    sed -ne '/^Package: \(.*\)/{s//\1/;h;};/^Installed-Size: \(.*\)/{s//\1/;G;s/\n/ /;p;}' /var/lib/dpkg/status | sort -rn
    arcege · 2009-10-19 19:01:17 24
  • To print a specific line from a file

    I don't know if it's better but works fine :)


    -5
    awk '{if (NR == 3) print}' <file>
    yooreck · 2009-10-19 15:58:09 5
  • List your largest installed packages (on Debian/Ubuntu)

    List packages and their disk usage in decreasing order. This uses the "Installed-Size" from the package metadata. It may differ from the actual used space, because e.g. data files (think of databases) or log files may take additional space. Show Sample Output


    0
    perl -ne '$pkg=$1 if m/^Package: (.*)/; print "$1\t$pkg\n" if m/^Installed-Size: (.*)/;' < /var/lib/dpkg/status | sort -rn | less
    hfs · 2009-10-19 12:55:59 7
  • Copy recursivelly files of specific filetypes

    Copying only wmv and mpg files recursively from to


    1
    rsync -rvtW --progress --include='*.wmv' --include='*.mpg' --exclude='*.*' <sourcedir> <destdir>
    MauricioVieira · 2009-10-19 10:38:11 4
  • encode image to base64 and copy to clipboard

    I use it for embedding images in CSS for Stylish, the Firefox addon. Thought it might be useful to others.


    1
    uuencode -m $1 /dev/stdout | sed '1d' | sed '$d' | tr -d '\n' | xclip -selection clipboard
    caliburning · 2009-10-19 09:03:09 4
  • Extract a bash function

    I often need to extract a function from a bash script and this command will do it. Show Sample Output


    8
    sed -n '/^function h\(\)/,/^}/p' script.sh
    haivu · 2009-10-19 07:55:35 33
  • geoip lookup


    4
    geoip(){curl -s "http://www.geody.com/geoip.php?ip=${1}" | sed '/^IP:/!d;s/<[^>][^>]*>//g' ;}
    twfcc · 2009-10-19 05:48:07 17
  • Battery real life energy vs predicted remaining plotted

    This time I added a print to reemaining energy, every minute, time stamped. The example shown here is complete and point to large discrepancies as time passes, converging to accuracy near the end. Show Sample Output


    1
    echo start > battery.txt; watch -n 60 'date >> battery.txt ; acpi -b >> battery.txt'
    m33600 · 2009-10-19 05:28:15 4
  • Localize provenance of current established connections

    Sample command to obtain a list of geographic localization for established connections, extracted from netstat. Need geoiplookup command ( part of geoip package under CentOS) Show Sample Output


    3
    for i in $(netstat --inet -n|grep ESTA|awk '{print $5}'|cut -d: -f1);do geoiplookup $i;done
    servermanaged · 2009-10-18 20:41:47 4
  • Do you really believe on Battery Remaining Time? Confirm it from time to time!

    Fully recharge your computer battery and start this script. It will create or clean the file named battery.txt, print a start on it and every minute it will append a time stamp to it. Batteries last few hours, and each hour will have 60 lines of time stamping. Really good for assuring the system was tested in real life with no surprises. The last time stamp inside the battery.txt file is of interest. It is the time the computer went off, as the battery was dead! Turn on your computer after that, on AC power of course, and open battery.txt. Read the first and last time stamps and now you really know if you can trust your computer sensors. If you want a simple line of text inside the battery.txt file, use this: watch -n 60 'date > battery.txt' The time of death will be printed inside Show Sample Output


    0
    echo start > battery.txt; watch -n 60 'date >> battery.txt'
    m33600 · 2009-10-18 07:00:26 4
  • Show current weather for any US city or zipcode

    Scrape the National Weather Service Show Sample Output


    4
    weather() { lynx -dump "http://mobile.weather.gov/port_zh.php?inputstring=$*" | sed 's/^ *//;/ror has occ/q;2h;/__/!{x;s/\n.*//;x;H;d};x;s/\n/ -- /;q';}
    zude · 2009-10-17 23:47:47 4
  • Get decimal ascii code from character

    printf treats first char after single ' as numeric equivalent


    1
    ord() { printf "%d\n" "'$1"; }
    zude · 2009-10-17 22:02:52 3
  • Make directories for and mount all iso files in a folder

    Show Sample Output


    2
    for file in *.iso; do mkdir `basename $file | awk -F. '{print $1}'`; sudo mount -t iso9660 -o loop $file `basename $file | awk -F. '{print $1}'`; done
    jaymzcd · 2009-10-17 20:07:31 4
  • Testing hard disk writing speed


    1
    time dd if=/dev/zero of=TEST bs=4k count=512000
    flojb · 2009-10-17 17:50:53 39
  • create iso image from a directory

    create iso image from directory . Usefull for virtualised machine To create CD ISO image of directories that contain long file name or non-8.3 format (particularly if you want to burn the CD image for use in Windows system), use the -J option switch that generates Joliet directory records in addition to regular iso9660 file names. For example, to create CD image of Vista SP1 directory: mkisofs -o VitaSP1.iso -J VistaSP1 Show Sample Output


    8
    mkisofs -o XYZ.iso XYZ/
    eastwind · 2009-10-17 16:28:47 53
  • Get decimal ascii code from character

    the shortest command for character 'a' i know Show Sample Output


    1
    echo -n a | od -d | sed -n "s/^.* //gp"
    stf42 · 2009-10-17 15:46:00 7
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recursive search and replace old with new string, inside files
Using -Z with grep and -0 with xargs handles file names with spaces and special characters.

Use find to get around Argument list too long problem
Can be used for other commands as well, replace rm with ls. It is easy to make this shorter but if the filenames involved have spaces, you will need to do use find's "-print0" option in conjunction with xargs's "-0" option. Otherwise the shell that xargs uses to execute the "rm" command line will treat the space as a token separator, thereby treating the name as two (or more) names.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Retrieve the size of a file on a server
Downloads the entire file, but http servers don't always provide the optional 'Content-Length:' header, and ftp/gopher/dict/etc servers don't provide a filesize header at all.

Sort all running processes by their memory & CPU usage
you can also pipe it to "tail" command to show 10 most memory using processes.

Create POSIX tar archive
tar(1) and cpio(1) are not fully platform agnostic, although their file formats are specified in POSIX.1-2001. As such, GNU tar(1) might not be able to extract a BSD tar(1) archive, and ivce versa. pax(1) is defined in POSIX.1-2001. To extract an archive: $ pax -rf archive.tar

BourneShell: Go to previous directory
cd - would return to the previous directory of your cd command. NB: previous dir is always stored in $OLDPWD variable.

Copy a file using dd and watch its progress
This is a more accurate way to watch the progress of a dd process. The $DDPID=$! is needed so that you don't get the PID of the sleep. The sleep 1 is needed because in my testing at least, if you run kill -USR1 against dd too quickly, it will kill it off instead of display the status. So you need to wait a second, probably so that it can configure itself to trap the USR1 signal.

Create arbitrary big file full of zeroes but done in a second
If you want to create fast a very big file for testing purposes and you do not care about its content, then you can use this command to create a file of arbitrary size within less than a second. Content of file will be all zero bytes. The trick is that the content is just not written to the disk, instead the space for it is somehow reserved on operating system level and file system level. It would be filled when first accessed/written (not sure about the mechanism that lies below, but it makes the file creation super fast). Instead of '1G' as in the example, you could use other modifiers like 200K for kilobytes (1024 bytes), 500M for megabytes (1024 * 1024 bytes), 20G for Gigabytes (1024*1024*1024 bytes), 30T for Terabytes (1024^4 bytes). Also P for Penta, etc... Command tested under Linux.

Find files with size over 100MB and output with better lay-out

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