Unfortunately I'm not at my own *nix system but on a - hrrrrgh - windows machine, so I can't test what I'm proposing here. It might still be a pointer in a desireable direction. Read and apply to taste:
and sort to taste as my awk doesn't offer a sort function.
I'm not sure I caught all subtleties of your request, please come back with any questions that might arise.
EDIT: Well, back at my desk, able to test, and I modified above to satisfy the request:
yields exactly the output desired. No END section needed as the header is sorted last and prints the H12 entry...
Hi,
I'm working hard on SQL and I came across a hurdle I'm hoping you can help me out with.
I have two tables
table1
headers: chrom start end name score strand
11 9720685 9720721 U0 0 +
21 9721043 9721079 U0 0 -
1 9721093 9721129 U0 0 +
20 ... (2 Replies)
Hi,
I want a UNIX command that can filter out rows with certain criteria.
The file is tab deliminated. Row one is just a value. Basically what I want to do is select based on the name and character at the end (o). So lets lets say i want a row that has WashU and (o) then it would print... (2 Replies)
Hi there, I have a text file with several colums separated by "|;#" I need to search the file extracting all columns starting with the value of "1" or "2" saving in a separate file just the first 7 columns of each row maching the criteria, with replacement of the saparators in the nearly created... (2 Replies)
Hi Guys,
I need help in modifying a large text file containing more than 1-2 lakh rows of data using unix commands. I am quite new to the unix language
the text file contains data in a pipe delimited format
sdfsdfs
sdfsdfsd
START_ROW
sdfsd|sdfsdfsd|sdfsdfasdf|sdfsadf|sdfasdf... (9 Replies)
Hi
My pipe delimited .txt file contains rows with 10 columns.
Can anyone advise how I output to file only those rows with the letters ‘ci'
as the first 2 characters in the 3rd column ?
Many thanks (4 Replies)
hi buddies;
i want to convert lines to tabs with a different sized. this is my text:
192.14.2.1 Sector=1 height 2500
Sector=3 height 2500
Sector=2 height 2500
PredefRbsScannerGpeh=1 fileLocation /c/pm_data/
SectorAntenna=3,AntennaBranch=A fqBandHighEdge 21550... (3 Replies)
Gurus,
From a file I need to remove duplicate rows based on the first column data but also we need to consider a date column where we need to keep the latest date (13th column).
Ex:
Input File:
Output File:
I know how to take out the duplicates but I couldn't figure out... (5 Replies)
HI all,
I have a simple challenge for you.. I have the following pipe delimited file
2345|98|1809||x|969|0
2345|98|0809||y|0|537
2345|97|9809||x|544|0
2345|97|0909||y|0|651
9685|98|7809||x|321|0
9685|98|7909||y|0|357
9685|98|7809||x|687|0
9685|98|0809||y|0|234
2315|98|0809||x|564|0
... (2 Replies)
I have a text file with 1,000,000 rows (It is a single column text file of numbers). I would like to separate the text file into 100 files of equal size (i.e. number of rows). The first file will contain the first 10,000 rows, the second row will contain the second 10,000 rows (rows 10,001-20,000)... (2 Replies)
Hello, everyone
I am beginner for shell programming. I want to print all lines that have the same values in first two columns
data:
a b 1 2
a a 3 4
b b 5 6
a b 4 6
what I expected is :
a a 3 4
b b 5 6
but I searched for one hour in... (2 Replies)
Discussion started by: nengcheng
2 Replies
LEARN ABOUT MOJAVE
sort5.18
sort(3pm) Perl Programmers Reference Guide sort(3pm)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 { $current = sort::current; }
print "$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 { $current = sort::current; }
print "$current
";
@c = sort @d;
}
perl v5.18.2 2013-11-04 sort(3pm)