Begginer alert!!
I have just started learning perl and have got stuck. I need to initialize a hash array with values from a list. I've been told to do this using a split command, but its just not happening.
Here is the script and output:
SCRIPT:
#!/bin/perl
system("clear");
... (5 Replies)
I have a script with dynamic hash of hashes , and I want to print the entire hash (with all other hashes).
Itried to do it recursively by checking if the current key is a hash and if yes call the current function again with refference to the sub hash.
Most of the printing seems to be OK but in... (1 Reply)
Hello!
For long I used cksum to find file duplicates in linux and darwin.
Now I want to make my own program that does all.
However I can't seem to find the correct algorithm.
zip and cksum claim to use the same algorithm, but the computated sums are not the same.
I've already written an... (4 Replies)
Can Someone explain me why even using Tie::IxHash I can not get the output data in the same order that it was inserted? See code below.
#!/usr/bin/perl
use warnings;
use Tie::IxHash;
use strict;
tie (my %programs, "Tie::IxHash");
while (my $line = <DATA>) {
chomp $line;
my(... (1 Reply)
Is cksum the right command to calculate the crc32 checksum value? I tried it for a number of files now and every time the results dont match. So there is nothing wrong with the file. Also, cksum gives me an all numerical value while crc32 is alpha numeric. What am I doing wrong?
Thanks (9 Replies)
Hi Folks
I am very much a newbie at perl but picking it up and I'm hoping you can help.
I have a file input that details all the /etc/group files in our enterprise in the following format: "<host>:<group>:<gid>:<users>"
I want to parse this data display it as the following:... (9 Replies)
I have the following code that print certain files in my directory and groups things together. I would be good to tidy and simplify this code up and would greatly appreciate suggestions.
if ($opt_raytrac == 1) then
echo ""
echo -n "\033*\)/ & /g' | sort -k 4n | sed 's/ //g' \
# |... (0 Replies)
Hi,
I have an hashes of hash, where hash is dynamic, it can be n number of hash. i need to compare data_count values of all .
my %result (
$abc => {
'data_count' => '10',
'ID' => 'ABC122',
}
$def => {
'data_count' => '20',
'ID' => 'defASe',
... (1 Reply)
Hello gurus, Iam trying to parse following BibTex file (bibliography.bib):
@book{Lee2000a,
abstract = {Abstract goes here},
author = {Lee, Wenke and Stolfo, Salvatore J},
title = {{Data mining approaches for intrusion detection}},
year = {2000}
}
@article{Forrest1996,
abstract =... (0 Replies)
Discussion started by: wakatana
0 Replies
LEARN ABOUT PHP
crc32
CRC32(3) 1 CRC32(3)crc32 - Calculates the crc32 polynomial of a stringSYNOPSIS
int crc32 (string $str)
DESCRIPTION
Generates the cyclic redundancy checksum polynomial of 32-bit lengths of the $str. This is usually used to validate the integrity of data
being transmitted.
Warning
Because PHP's integer type is signed many crc32 checksums will result in negative integers on 32bit platforms. On 64bit installa-
tions all crc32(3) results will be positive integers though.
So you need to use the "%u" formatter of sprintf(3) or printf(3) to get the string representation of the unsigned crc32(3) checksum
in decimal format.
For a hexadecimal representation of the checksum you can either use the "%x" formatter of sprintf(3) or printf(3) or the dechex(3)
conversion functions, both of these also take care of converting the crc32(3) result to an unsigned integer.
Having 64bit installations also return negative integers for higher result values was considered but would break the hexadecimal
conversion as negatives would get an extra 0xFFFFFFFF######## offset then. As hexadecimal representation seems to be the most common
use case we decided to not break this even if it breaks direct decimal comparisons in about 50% of the cases when moving from 32 to
64bits.
In retrospect having the function return an integer maybe wasn't the best idea and returning a hex string representation right away
(as e.g. md5(3) does) might have been a better plan to begin with.
For a more portable solution you may also consider the generic hash(3). hash("crc32b", $str) will return the same string as
dechex(crc32($str)).
PARAMETERS
o $str
- The data.
RETURN VALUES
Returns the crc32 checksum of $str as an integer.
EXAMPLES
Example #1
Displaying a crc32 checksum
This example shows how to print a converted checksum with the printf(3) function:
<?php
$checksum = crc32("The quick brown fox jumped over the lazy dog.");
printf("%u
", $checksum);
?>
SEE ALSO hash(3), md5(3), sha1(3).
PHP Documentation Group CRC32(3)