Commands using rev (16)

  • 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. Show Sample Output


    13
    sitepass() { echo -n "$@" | md5sum | sha1sum | sha224sum | sha256sum | sha384sum | sha512sum | gzip - | strings -n 1 | tr -d "[:space:]" | tr -s '[:print:]' | tr '!-~' 'P-~!-O' | rev | cut -b 2-11; history -d $(($HISTCMD-1)); }
    grokskookum · 2009-10-01 20:14:57 14
  • Your name backwards


    4
    echo "$USER"|rev | espeak
    bugmenot · 2016-05-26 16:10:20 12
  • Copy input sent to a command to stderr

    In the above example 'muspi merol' (the output of the first rev command) is sent to stderr and 'lorem ipsum' (the output of the second rev command) is sent to stdout. rev reverse lines of a file or files. This use of tee allows testing if a program correctly handles its input without using files that hold the data. Show Sample Output


    2
    rev <<< 'lorem ipsum' | tee /dev/stderr | rev
    penpen · 2009-03-31 13:12:09 7
  • Nicely display permissions in octal format with filename

    Since the original command (#1873) didn't work on FreeBSD whose stat lacks the "-c" switch, I wrote an alternative that does. This command shows also the fourth digit of octal format permissions which yields the sticky bit information. Show Sample Output


    2
    stat -f '%Sp %p %N' * | rev | sed -E 's/^([^[:space:]]+)[[:space:]]([[:digit:]]{4})[^[:space:]]*[[:space:]]([^[:space:]]+)/\1 \2 \3/' | rev
    vwal · 2009-08-04 08:45:20 3
  • Slightly better compressed archives

    Avoids creating useless directory entries in archive, and sorts files by (roughly) extension, which is likely to group similar files together for better compression. 1%-5% improvement.


    2
    find . \! -type d | rev | sort | rev | tar c --files-from=- --format=ustar | bzip2 --best > a.tar.bz2
    pornel · 2009-12-20 14:04:39 4
  • Give {Open,True}Type files reasonable names

    Just a quick hack to give reasonable filenames to TrueType and OpenType fonts. I'd accumulated a big bunch of bizarrely and inconsistently named font files in my ~/.fonts directory. I wanted to copy some, but not all, of them over to my new machine, but I had no idea what many of them were. This script renames .ttf files based on the name embedded inside the font. It will also work for .otf files, but make sure you change the mv part so it gives them the proper extension. REQUIREMENTS: Bash (for extended pattern globbing), showttf (Debian has it in the fontforge-extras package), GNU grep (for context), and rev (because it's hilarious). BUGS: Well, like I said, this is a quick hack. It grew piece by piece on the command line. I only needed to do this once and spent hardly any time on it, so it's a bit goofy. For example, I find 'rev | cut -f1 | rev' pleasantly amusing --- it seems so clearly wrong, and yet it works to print the last argument. I think flexibility in expressiveness like this is part of the beauty of Unix shell scripting. One-off tasks can be be written quickly, built-up as a person is "thinking aloud" at the command line. That's why Unix is such a huge boost to productivity: it allows each person to think their own way instead of enforcing some "right way". On a tangent: One of the things I wish commandlinefu would show is the command line HISTORY of the person as they developed the script. I think it's that conversation between programmer and computer, as the pipeline is built piece-by-piece, that is the more valuable lesson than any canned script. Show Sample Output


    2
    shopt -s extglob; for f in *.ttf *.TTF; do g=$(showttf "$f" 2>/dev/null | grep -A1 "language=0.*FullName" | tail -1 | rev | cut -f1 | rev); g=${g##+( )}; mv -i "$f" "$g".ttf; done
    hackerb9 · 2010-04-30 09:46:45 7
  • Generate a Random Password

    I know there are a lot of random password generators out there, but I wanted something that put out something besides hex. Set count equal to the number of bytes you want. Show Sample Output


    0
    dd if=/dev/urandom bs=1 count=32 2>/dev/null | base64 -w 0 | rev | cut -b 2- | rev
    TyIzaeL · 2009-02-17 23:36:24 15
  • Remove the last string character using rev and cut

    In case sed and awk are not available you may use this to remove the last character from a string with "rev" and "cut". Show Sample Output


    0
    echo "command lines" | rev | cut -c 2- | rev
    ztank1013 · 2011-09-21 11:27:52 7
  • Convert mp4 to mp3 in a directory

    Good for when you download youtube videos and want the mp3 for your mp3 player.


    0
    for a in $(find . -maxdepth 1 -name "*.mp4" -type f -printf "%f\n" | rev | cut -d '.' -f2- | rev | sort -u); do if [ ! -f "$a.mp3" ]; then avconv -i "$a."* -vn -ab 128 "$a.mp3"; fi done
    adanisch · 2014-06-27 05:13:53 7
  • Grep auth log and print ip of attackers

    Find the failed lines, reverse the output because I only see 3 indicators after the IP address, i.e. port, port#, ssh2 (in my file), cut to the 4th field (yes, you could awk '{print $4}'), reverse the output back to normal and then sort -u (for uniq, or sort | uniq). Show Sample Output


    0
    grep Failed auth.log | rev | cut -d\ -f4 | rev | sort -u
    supradave · 2014-08-14 14:57:41 8
  • Get the IP address of a machine. Just the IP, no junk.

    Gives the DNS listed IP for the host you're on... or replace `hostname` with any other host Show Sample Output


    0
    host `hostname` | rev | cut -d' ' f1 | rev
    shaggyhiggins · 2014-10-01 18:55:05 8
  • Remove duplicate files from the current directory

    Remove everything after the second "rev" to only display the duplicate filenames and their hashes.


    0
    sha1sum * | sort | rev | uniq -df1 | rev | cut -d" " -f3 | xargs rm
    Sparkette · 2015-08-09 20:32:12 9
  • Find Rhyming Words

    rhyme time mime rhyme lowrez Juarez


    0
    rhyme() { { cat /usr/share/dict/words; printf %s\\n "$1"; } | rev | sort | rev | grep -FxC15 -e "${1?}" | grep -Fxve "$1" | shuf -n1; }
    lowrez · 2016-01-02 03:24:44 13
  • [MySQL] Get which table were dumped in [mysql_dump_file]

    Show Sample Output


    0
    cat [mysql_dump_file] | grep "Table structure" | cut -c 30- | tr '\n' ' ' | rev | cut -c 2- | rev | tr -d '`'
    Lidorah · 2017-02-08 09:26:01 16
  • copy all Photos from Canon A520 to one place

    You must spezify /where folder and / folder If you have another camera you must experiment with Exif data (after -g and after grep) and mask of your photo files IMG_????.JPG I have do it on Knoppix 6.7.0 You must have installed exiv2. Show Sample Output


    -1
    find / -type f -name IMG_????.JPG -print0 |xargs -0 exiv2 -g Exif.Canon.ModelID '{}' |grep A520 |rev |cut --complement -d " " -f1-40 |rev |xargs -I {} cp --parents {} /where
    fladam · 2012-03-10 03:01:01 4
  • Calculate 1**2 + 2**2 + 3**2 + ...

    I can't put the last ^2 with seq, so I reverse it to delete the last +N. So for doing sum(N^2) you have to do sum((N+1)^2). Must be a better way. Show Sample Output


    -2
    seq -s^2+ 11 |rev| cut -d'+' -f2- | rev | bc
    rubenmoran · 2011-02-10 08:41:14 8

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Exclude inserting a table from a sql import
Starting with a large MySQL dump file (*.sql) remove any lines that have inserts for the specified table. Sometimes one or two tables are very large and uneeded, eg. log tables. To exclude multiple tables you can get fancy with sed, or just run the command again on subsequently generated files.

E-mail a traditional Berkeley mbox to another recipient as individual e-mails.

Swap a file or dir with quick resotre
This lets you replace a file or directory and quickly revert if something goes wrong. For example, the current version of a website's files are in public_html. Put a new version of the site in public_html~ and execute the command. The names are swapped. If anything goes wrong, execute it again (up arrow or !!).

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"

List all Windows services on the command line
On Windows 2000 or later, this command will give a listing of all the registered Windows services. You can then know what the name of a command is in order to start and stop it. e.g. $ sc start Apache2.2 or $ net start Apache2.2 Please note that sc will allow the SERVICE_NAME only, while net will allow both SERVICE_NAME and DISPLAY_NAME. Note that the space between the = and the next word are important. Not very unixy, that. http://www.ss64.com/nt/sc.html http://www.ss64.com/nt/net_service.html http://technet.microsoft.com/en-us/library/bb490995.aspx

Grep for regular expression globally, list files and positions.
Grep for expression globally, list files and positions. "Hirn" is a nice german crib meaning "Brain". :-) Afterwards you can edit the line you want with "vi ./p_common/common_main.pbt +1550"

Compare a remote dir with a local dir
You can compare directories on two different remote hosts as well: $ diff -y

Rename all .jpeg and .JPG files to have .jpg extension
the "i" controls case sensitiveness. It's slightly inefficient since it uselessly renames .jpg to .jpg, but that's more than compensated by launching only one process instead of two, besides being shorter to write.

Insert a line for each n lines

Print a row of characters across the terminal
Print a row of characters across the terminal. Uses tput to establish the current terminal width, and generates a line of characters just long enough to cross it. In the example '#' is used. It's possible to use a repeating sequence by dividing the columns by the number of characters in the sequence like this: $ seq -s'~-' 0 $(( $(tput cols) /2 )) | tr -d '[:digit:]' or $ seq -s'-~?' 0 $(( $(tput cols) /3 )) | tr -d '[:digit:]' You will lose chararacters at the end if the length isn't cleanly divisible.

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