You may try something like this:
Note that some awk implementations (or some system settings) could limit the number of concurrently open files, in that case you could use something like this:
Set l to the desired value (the # of open files).
thanks it's working well and also very fast. never think it's can be done by single line awk. i want to know also how to calculate the number of record base on value on column 1 and 2 , so the data after i extract is
Hi,
i want to match a string using perl that has got 5 pluses(+++++).
i am using a function for this.
$str1="+++++";
check($str1,"\\+");
sub check{
$str1=$_;
$str2=$_;
if($str1=~m/^$str2{5}$/){
print "Correct.\n";
}else{
print "Wrong..\n";
... (6 Replies)
Hi,
I am trying to grep for the following type of string from a document given below:
12637 1239 3356 12956 7004 7004 7004 13381 13381
*> 12.0.1.63 0 7018 21872 ?
* 208.51.134.254 53 0 3549 7018 21872 ?... (1 Reply)
Can anyone give the detailed explanation on regex search
i want to know the use of regex in sed and awk also......
the operators like ^,.,* ....etc i need it with some example.....kindly help on this.
I gone through the man pages also..but i was not clear......... (1 Reply)
I would like to search strings composed by only one type of charachter for example
only strings composed by the charachter 'b'
is it right?
$egrep '\<(b+)+\>' filename
Could be there some side effects?
Regards. (1 Reply)
I am having trouble parsing rpm filenames in a shell script.. I found a snippet of perl code that will perform the task but I really don't have time to rewrite the entire script in perl. I cannot for the life of me convert this code into something sed-friendly:
if ($rpm =~ /(*)-(*)-(*)\.(.*)/)... (1 Reply)
I have a regex I'd like to implement and I believe it should be working and I have tested it on various websites that have regex testers but it always says the name is invalid.
#!/bin/bash -x
echo Enter the users first and last name.
read name
if... (11 Replies)
I have a file of protein sequences with headers (my source file). Based on a list of IDs (which are included in some of the headers), I'd like to print out only the specified sequences, with only the ID as header.
In other words, I'd like to search source.txt for the terms in IDs.txt, and print... (3 Replies)
I am not a big expert in regex and have just little understanding of that language.
Could you help me to understand the regular Perl expression:
^(?!if\b|else\b|while\b|)(?:+?\s+){1,6}(+\s*)\(*\) *?(?:^*;?+){0,10}\{
------
This is regex to select functions from a C/C++ source and defined in... (2 Replies)
Here i am writing a script to check&display only the valid mail address from a file
echo "Plz enter the Target file name with path"
read path
if
then
echo "The valid mail address are:"
email=$(grep -E -o "\b+@+\.{2,6}\b" $path )
echo "$email"
fi
The file contains the data like this:... (6 Replies)
I'm trying to get some exclusions into our sendmail regular expression for the K command. The following configuration & regex works:
LOCAL_CONFIG
#
Kcheckaddress regex -a@MATCH
+<@+?\.++?\.(us|info|to|br|bid|cn|ru)
LOCAL_RULESETS
SLocal_check_mail
# check address against various regex... (0 Replies)
Discussion started by: RobbieTheK
0 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)