Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Bash - array loop performance
Top Forums Shell Programming and Scripting Bash - array loop performance Post 302919565 by math4 on Thursday 2nd of October 2014 06:14:16 AM
Old 10-02-2014
I have rewrite the function in perl: wow, very fast!
I like perl seem easy to understand.
If someone is interested...

Code:
sub decrypt {
    my ($f, $key) = @_;
    my $s;
    {
      local *FH;
      open FH, "$f" or die $!;
      -f FH and sysread FH, $s, -s FH;
    }
    my $n=length($s);
    my $k1=11+($key % 233); my $k2= 7+($key % 239);
    my $k3= 5+($key % 241); my $k4= 3+($key % 251);
    my @sn = unpack("C*", $s);   
  # debug: print "@sn\n";
    my $i=0;
    for ($i=0; $i<($n-2); $i++) { $sn[$i]=(($sn[$i] ^ $sn[$i+2] ^ ($k4 * $sn[$i+1])) % 256); }
    for ($i=($n-1); $i>1; $i--) { $sn[$i]=(($sn[$i] ^ $sn[$i-2] ^ ($k3 * $sn[$i-1])) % 256); }
    for ($i=0; $i<($n-1); $i++) { $sn[$i]=(($sn[$i] ^ $sn[$i+1] ^ ($k2 * $sn[$i+1])) % 256); }
    for ($i=($n-1); $i>0; $i--) { $sn[$i]=(($sn[$i] ^ $sn[$i-1] ^ ($k1 * $sn[$i-1])) % 256); }
    $s=""; for ($i=0; $i<$n; $i++) { $s.=chr( $sn[$i] ); }  
}

 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Using variables created sequentially in a loop while still inside of the loop [bash]

I'm trying to understand if it's possible to create a set of variables that are numbered based on another variable (using eval) in a loop, and then call on it before the loop ends. As an example I've written a script called question (The fist command is to show what is the contents of the... (2 Replies)
Discussion started by: DeCoTwc
2 Replies

2. Shell Programming and Scripting

problem access array outside of loop in bash

Below is a test script I was trying to use so that I could understand why the logic was not working in a larger script. While accessing and printing array data inside the while loop, everything is fine. Outside the loop, i guess everything is null?? The for loop that is meant to cycle... (4 Replies)
Discussion started by: adlmostwanted
4 Replies

3. Shell Programming and Scripting

Array Variable being Assigned Values in Loop, But Gone when Loop Completes???

Hello All, Maybe I'm Missing something here but I have NOOO idea what the heck is going on with this....? I have a Variable that contains a PATTERN of what I'm considering "Illegal Characters". So what I'm doing is looping through a string containing some of these "Illegal Characters". Now... (5 Replies)
Discussion started by: mrm5102
5 Replies

4. Shell Programming and Scripting

Bash 3.2 - Array / Regex - IF 3rd member in array ends in 5 digits then do somthing...

Trying to do some control flow parsing based on the index postion of an array member. Here is the pseudo code I am trying to write in (preferably in pure bash) where possible. I am thinking regex with do the trick, but need a little help. pesudo code if == ENDSINFIVEINTS ]]; then do... (4 Replies)
Discussion started by: briandanielz
4 Replies

5. Shell Programming and Scripting

awk loop using array:wish to store array values from loop for use outside loop

Here's my code: awk -F '' 'NR==FNR { if (/time/ && $5>10) A=$2" "$3":"$4":"($5-01) else if (/time/ && $5<01) A=$2" "$3":"$4-01":"(59-$5) else if (/time/ && $5<=10) A=$2" "$3":"$4":0"($5-01) else if (/close/) { B=0 n1=n2; ... (2 Replies)
Discussion started by: klane
2 Replies

6. UNIX for Advanced & Expert Users

How to test RAID10 array performance [Debian Wheezy]?

I have created a RAID10 array (near layout) with four 8 GiB virtual hard drives, making a 16 GiB array (/dev/md0 formatted as ext4). On the other hand, I have a 16 GiB RAID1 array (/dev/md1, also formatted as ext4). The purpose of these setups is to compare the read and write performances of each... (13 Replies)
Discussion started by: gacanepa
13 Replies

7. Shell Programming and Scripting

Bash arrays: rebin/interpolate smaller array to large array

hello, i need a bit of help on how to do this effectively in bash without a lot of extra looping or massive switch/case i have a long array of M elements and a short array of N elements, so M > N always. M is not a multiple of N. for case 1, I want to stretch N to fit M arrayHuge H = (... (2 Replies)
Discussion started by: f77hack
2 Replies

8. UNIX for Beginners Questions & Answers

Bash array variables are changed in loop runtime

I am trying to check whether particular host and port are responding or not. I am using below script to check. but node_port array that i am using in loop is getting replaced with previous iteration value. Script and output is given. Please help me to understanding why node_port values are... (5 Replies)
Discussion started by: tmalik79
5 Replies

9. Shell Programming and Scripting

Bash Array connectin to another Array

Hello, i have a script that i need account_number to match a name. for exsample : ACCOUNT_ID=(IatHG8DC7mZbdymSoOr11w KbnlG2j-KRQ0-1_Xk356s8) and i run a loop curl requst with this the issue is that i want to know on which account were talking about so bash will know this : ... (4 Replies)
Discussion started by: batchenr
4 Replies

10. Shell Programming and Scripting

Bash for loop array

Hi there, A bit new to bash and am having an issue with a for loop. I look for filenames in a specified directory and pull the date string from each meeting a certain criteria, and then would like to make a directory for each date found, like this: search 20180101.gz 20180102.gz 20180103.gz... (5 Replies)
Discussion started by: mwheeler12
5 Replies

LEARN ABOUT DEBIAN

crypt::twofish

Twofish(3pm)						User Contributed Perl Documentation					      Twofish(3pm)

NAME

       Crypt::Twofish - The Twofish Encryption Algorithm

SYNOPSIS

       use Crypt::Twofish;

       $cipher = Crypt::Twofish->new($key);

       $ciphertext = $cipher->encrypt($plaintext);

       $plaintext  = $cipher->decrypt($ciphertext);

DESCRIPTION

       Twofish is a 128-bit symmetric block cipher with a variable length (128, 192, or 256-bit) key, developed by Counterpane Labs. It is
       unpatented and free for all uses, as described at <URL:http://www.counterpane.com/twofish.html>.

       This module implements Twofish encryption. It supports the Crypt::CBC interface, with the functions described below. It also provides an
       interface that is call-compatible with Crypt::Twofish 1.0, but its use in new code is strongly discouraged.

   Functions
       blocksize
	   Returns the size (in bytes) of the block (16, in this case).

       keysize
	   Returns the size (in bytes) of the key. Although the module understands 128, 192, and 256-bit keys, it returns 16 for compatibility
	   with Crypt::CBC.

       new($key)
	   This creates a new Crypt::Twofish object with the specified key (which should be 16, 24, or 32 bytes long).

       encrypt($data)
	   Encrypts blocksize() bytes of $data and returns the corresponding ciphertext.

       decrypt($data)
	   Decrypts blocksize() bytes of $data and returns the corresponding plaintext.

SEE ALSO

       Crypt::CBC, Crypt::Blowfish, Crypt::TEA

ACKNOWLEDGEMENTS

       Nishant Kakani
	   For writing Crypt::Twofish 1.0 (this version is a complete rewrite).

       Tony Cook
	   For making the module work under Activeperl, testing on several platforms, and suggesting that I probe for features via %Config.

AUTHOR

       Abhijit Menon-Sen <ams@wiw.org>

       Copyright 2001 Abhijit Menon-Sen. All rights reserved.

       This software is distributed under the terms of the Artistic License <URL:http://ams.wiw.org/code/artistic.txt>.

perl v5.14.2							    2001-05-21							      Twofish(3pm)
All times are GMT -4. The time now is 11:20 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy