Thanks for your reply, i missed that.
I have one more question. i have code like below , i need to get the text between certain patterns , suppose i have below array
as first pattern match the required text will be in $1 and As second pattern match the required text will be in $2.
but when first pattern match $2 is empty it will give warning like this Use of uninitialized value $2 in concatenation (.) or string at
So how to avoid those warnings .. please help me..
Hi all,
I am trying to match a multi line string and return the matching string in one line. Here is the perl code that I wrote:
#!/usr/bin/perl
my $str='<title>My
title</title>';
if ($str =~ /(<title>)(+)(<\/title>)/ ){
print "$2\n";
}
It returns :
My
title
I want the... (3 Replies)
letz say that my file has 7 records with only one field. So my file has:
11111111
000000000000000
1111
aaaabbbccc
1111111222000000
aaaaaaaa
zz
All i need is:
1. when the field has a repetition of the same instance(a-z or 0-9), i would consideer it to be invalid.... (1 Reply)
Hello all,
I need to match the red expressions in the following lines :
MACRO_P+P-_scrambledServices_REM_PRC30.xml
MACRO_P+P-_scrambledServices_REM_RS636.xml
MACRO_P+P-_scrambledServices_REM_RS535.xml
and so on...
Can anyone give me a PERL regular expression to match those characters ?
... (5 Replies)
Hi,
I need and expression for a word like abc_xyz_ykklm
The expresion should indicate that the word starts with abc and end with ykklm but does not contain xyz string in the middle.
Example: abc_tmn_ykklm is ok and abc_xyz_ykklm is not Ok.
Please help.
Regards. (1 Reply)
Hello,
I am trying to use perl LWP module to read and get a specfic URL page. The issue is that the URL ends with the data and time and time is not consistent it changes all the time. if anyone could help me how to write a regular expressin that would work in the LWP::UserAgent get function to... (0 Replies)
Could you help me with this please. This regular expression seems to match for the wrong input
#!/usr/bin/perl
my $inputtext = "W1a$%XXX";
if($inputtext =~ m/+X+/)
{
print "matches\n";
}
The problem seems to be %. if inputtext is W1a$XXX, the regex doesnot match.... (5 Replies)
I am completely new to perl programming. My father is helping me learn said programming language. However, I am stuck on one of the assignments he has given me, and I can't find very much help with it via google, either because I have a tiny attention span, or because I can be very very dense.
... (4 Replies)
Hi I am doing something basic like...
if ($stringvariable =~ /have not typed/)
I have a little problem because the 'not' in the expression gets highlighted as a kind of a '!'..what am I supposed to do in this situation?
Thank you
---------- Post updated at 03:24 PM ----------... (1 Reply)
Hi all,
How am I read a file, find the match regular expression and overwrite to the same files.
open DESTINATION_FILE, "<tmptravl.dat" or die "tmptravl.dat";
open NEW_DESTINATION_FILE, ">new_tmptravl.dat" or die "new_tmptravl.dat";
while (<DESTINATION_FILE>)
{
# print... (1 Reply)
Discussion started by: jessy83
1 Replies
LEARN ABOUT DEBIAN
bup-margin
bup-margin(1) General Commands Manual bup-margin(1)NAME
bup-margin - figure out your deduplication safety margin
SYNOPSIS
bup margin [options...]
DESCRIPTION
bup margin iterates through all objects in your bup repository, calculating the largest number of prefix bits shared between any two
entries. This number, n, identifies the longest subset of SHA-1 you could use and still encounter a collision between your object ids.
For example, one system that was tested had a collection of 11 million objects (70 GB), and bup margin returned 45. That means a 46-bit
hash would be sufficient to avoid all collisions among that set of objects; each object in that repository could be uniquely identified by
its first 46 bits.
The number of bits needed seems to increase by about 1 or 2 for every doubling of the number of objects. Since SHA-1 hashes have 160 bits,
that leaves 115 bits of margin. Of course, because SHA-1 hashes are essentially random, it's theoretically possible to use many more bits
with far fewer objects.
If you're paranoid about the possibility of SHA-1 collisions, you can monitor your repository by running bup margin occasionally to see if
you're getting dangerously close to 160 bits.
OPTIONS --predict
Guess the offset into each index file where a particular object will appear, and report the maximum deviation of the correct answer
from the guess. This is potentially useful for tuning an interpolation search algorithm.
--ignore-midx
don't use .midx files, use only .idx files. This is only really useful when used with --predict.
EXAMPLE
$ bup margin
Reading indexes: 100.00% (1612581/1612581), done.
40
40 matching prefix bits
1.94 bits per doubling
120 bits (61.86 doublings) remaining
4.19338e+18 times larger is possible
Everyone on earth could have 625878182 data sets
like yours, all in one repository, and we would
expect 1 object collision.
$ bup margin --predict
PackIdxList: using 1 index.
Reading indexes: 100.00% (1612581/1612581), done.
915 of 1612581 (0.057%)
SEE ALSO bup-midx(1), bup-save(1)BUP
Part of the bup(1) suite.
AUTHORS
Avery Pennarun <apenwarr@gmail.com>.
Bup unknown-bup-margin(1)