"would be to translate them to numbers, do a numerical comparison,"
Thanks
---------- Post updated at 07:00 AM ---------- Previous update was at 06:49 AM ----------
Quote:
Originally Posted by pludi
What about d-z, A-Z, 0-9, ...? What about values with more than 1 character?
One possible approach, if it's only a few possible characters (=< 10), would be to translate them to numbers, do a numerical comparison, and translate them back after sorting, eg:
What about if @test = qw/aaa bb 44 BB9/, the output sequence is "BB9 bb aaa 44"? i tried using the code yours, but cannot achieve.
Hi,
Is there any way to sort a file in cshell by sort command, sorting it by multiple fields, like to sort it first by the second column and then by the first column.
Thanks forhead (1 Reply)
Hi all,
I am trying to extract the values ( text between the xml tags) based on the Order Number.
here is the sample input
<?xml version="1.0" encoding="UTF-8"?>
<NJCustomer>
<Header>
<MessageIdentifier>Y504173382</MessageIdentifier>
... (13 Replies)
Hi All,
When i give ls -ltr my filenames looks like this:
Filename Pattern: Abc_Def_mmddyyyyHHmm.csv
$ ls -ltr
Jun 05 04:30 Abc_Def_060520111245.csv
Jun 05 08:40 Abc_Def_071220121458.csv
Jun 06 03:30 Abc_Def_071220111458.csv
Jun 06 04:25 Abc_Def_060620110439.csv
Jun 07 04:37... (12 Replies)
Hi,
I am having trouble sorting one file based on another file. I tried the grep -f function and failed. Basically what I have is two files that look like this:
File 1 (the list)
gh
aba
for
hmm
File 2 ( the file that needs to be sorted)
aba 2 4 6 7
for 2 4 7 4... (4 Replies)
Hi,
I am able to get next line if it is matching a particular pattern. But i need a way to skip if next line also matches same pattern..
For example:
No Records
No Records
Records found
got it
Records found
Now i want to find 'Records found' after 'No Records' pattern matches..
... (5 Replies)
I have a file which has the following data :-
how can I sort the data in descending order .
My files may have the first column with 1 to 10000 numbers .I need to arrange them in descending order .
Thanks (2 Replies)
Hi there, I am pretty new to those things, so I couldn't figure out how to solve this, and if it is actually that easy. just found that awk could help:(.
so i have a textfile with strings and numbers (originally copy pasted from word, therefore some empty cells) in the following structure:
SC... (9 Replies)
Hi,
i need to sort content of files based on a specific value. An example as below.
Input1.txt
Col_1
SW_MH2_ST
ST_F72_9S
SW_MH3_S6
Col_2
SW_MH3_AS7
ST_S15_9CH
SW_MH3_AS8
SW_MH3_ST
Col_3
ST_M93_SZ
ST_C16_TC (12 Replies)
Hi,
This is one of the thing that am looking for when I post the question on the ps wrapper. It has since been closed as it has taken me too long to post an example.
I have replaced some of the original content of the ps output.
uname -a = SunOS <hostname> 5.11 11.3 sun4v sparc sun4v
... (1 Reply)
Hi All ,
I am having an input file like this
Input file
7 sks/jsjssj/ddjd/hjdjd/hdhd/Q 10 0.5 13
dkdkd/djdjd/djdjd/djd/QB 01 0.5
ldld/dkd/jdf/fjfjf/fjf/Q 0.5
10 sjs/jsdd/djdkd/dhd/Q 01 0.5 21
kdkd/djdd/djdd/jdd/djd/QB 01 0.5
dkdld/djdjd/djd/Q 01 0.5
... (9 Replies)
Discussion started by: kshitij
9 Replies
LEARN ABOUT DEBIAN
sort
sort(3perl) Perl Programmers Reference Guide sort(3perl)NAME
sort - perl pragma to control sort() behaviour
SYNOPSIS
use sort 'stable'; # guarantee stability
use sort '_quicksort'; # use a quicksort algorithm
use sort '_mergesort'; # use a mergesort algorithm
use sort 'defaults'; # revert to default behavior
no sort 'stable'; # stability not important
use sort '_qsort'; # alias for quicksort
my $current;
BEGIN {
$current = sort::current(); # identify prevailing algorithm
}
DESCRIPTION
With the "sort" pragma you can control the behaviour of the builtin "sort()" function.
In Perl versions 5.6 and earlier the quicksort algorithm was used to implement "sort()", but in Perl 5.8 a mergesort algorithm was also
made available, mainly to guarantee worst case O(N log N) behaviour: the worst case of quicksort is O(N**2). In Perl 5.8 and later,
quicksort defends against quadratic behaviour by shuffling large arrays before sorting.
A stable sort means that for records that compare equal, the original input ordering is preserved. Mergesort is stable, quicksort is not.
Stability will matter only if elements that compare equal can be distinguished in some other way. That means that simple numerical and
lexical sorts do not profit from stability, since equal elements are indistinguishable. However, with a comparison such as
{ substr($a, 0, 3) cmp substr($b, 0, 3) }
stability might matter because elements that compare equal on the first 3 characters may be distinguished based on subsequent characters.
In Perl 5.8 and later, quicksort can be stabilized, but doing so will add overhead, so it should only be done if it matters.
The best algorithm depends on many things. On average, mergesort does fewer comparisons than quicksort, so it may be better when
complicated comparison routines are used. Mergesort also takes advantage of pre-existing order, so it would be favored for using "sort()"
to merge several sorted arrays. On the other hand, quicksort is often faster for small arrays, and on arrays of a few distinct values,
repeated many times. You can force the choice of algorithm with this pragma, but this feels heavy-handed, so the subpragmas beginning with
a "_" may not persist beyond Perl 5.8. The default algorithm is mergesort, which will be stable even if you do not explicitly demand it.
But the stability of the default sort is a side-effect that could change in later versions. If stability is important, be sure to say so
with a
use sort 'stable';
The "no sort" pragma doesn't forbid what follows, it just leaves the choice open. Thus, after
no sort qw(_mergesort stable);
a mergesort, which happens to be stable, will be employed anyway. Note that
no sort "_quicksort";
no sort "_mergesort";
have exactly the same effect, leaving the choice of sort algorithm open.
CAVEATS
As of Perl 5.10, this pragma is lexically scoped and takes effect at compile time. In earlier versions its effect was global and took
effect at run-time; the documentation suggested using "eval()" to change the behaviour:
{ eval 'use sort qw(defaults _quicksort)'; # force quicksort
eval 'no sort "stable"'; # stability not wanted
print sort::current . "
";
@a = sort @b;
eval 'use sort "defaults"'; # clean up, for others
}
{ eval 'use sort qw(defaults stable)'; # force stability
print sort::current . "
";
@c = sort @d;
eval 'use sort "defaults"'; # clean up, for others
}
Such code no longer has the desired effect, for two reasons. Firstly, the use of "eval()" means that the sorting algorithm is not changed
until runtime, by which time it's too late to have any effect. Secondly, "sort::current" is also called at run-time, when in fact the
compile-time value of "sort::current" is the one that matters.
So now this code would be written:
{ use sort qw(defaults _quicksort); # force quicksort
no sort "stable"; # stability not wanted
my $current;
BEGIN { $current = print sort::current; }
print "$current
";
@a = sort @b;
# Pragmas go out of scope at the end of the block
}
{ use sort qw(defaults stable); # force stability
my $current;
BEGIN { $current = print sort::current; }
print "$current
";
@c = sort @d;
}
perl v5.14.2 2010-12-30 sort(3perl)