Thanks for the help all instances i have tried so far just look to work ok but never write the output to the textfile i am not sure if i am doing something wrong but.
place Textfile1 and Textfile2 on my backtrack5r3 desktop create a new file sort.py paste in the code and open a console window ./sort.py and it seems to be working but the textfiles are both unchanged when it's finished.
OK. Now I'm confused again.
There is no sorting involved in this project. So, why do the title of this thread and the name of your script contain the word sort?
None of the suggested scripts that have been provided in this thread use python. So, why are you saving these shell scripts in a file with a .py filename extension?
Please reset Textfile1 and Textfile2 to their original state, load my script into sort.py, and show us the exact output (both standard output and standard error) you get from the commands:
I have 2 text files, both have one simple, single column. The 2 files might be the same length, or might not, and if not, it's unknown which one would be longer.
For this example, file1 is longer:
---file1
Joe
Bob
Mary
Sally
Fred
Elmer
David
---file2
Tomato
House
Car... (3 Replies)
Hello,
My apologies if this has been posted elsewhere, I have had a look at several threads but I am still confused how to use these functions. I have two files, each with 5 columns:
File A: (tab-delimited)
PDB CHAIN Start End Fragment
1avq A 171 176 awyfan
1avq A 172 177 wyfany
1c7k A 2 7... (3 Replies)
the sorting is based on name of file,
file size
modification time stamps o f file
it should dislay the output in the following format
"." and ".." enteries should be ignored
please give some idea how to do it (1 Reply)
I have multiple files; each file contains a certain data in a column view
simply i want to combine all those files into one file in columns
example
file1:
a
b
c
d
file 2:
1
2
3
4
file 3:
G (4 Replies)
Hello,
I am trying to add a line (usually just a word) to some text files in a directory that are already sorted. I just don't want to run the sort command again because it can take a long time when the text or log files are really huge. I have a bashscript that will take in the 1st argument... (7 Replies)
Hi
I have a requirement like below
I need to sort the files based on the timestamp in the file name and run them in sorted order and then archive all the files which are one day old to temp directory
My files looks like this
PGABOLTXML1D_201108121235.xml... (1 Reply)
Hi,
I have 20 tab delimited text files that have a common column (column 1). The files are named GSM1.txt through GSM20.txt. Each file has 3 columns (2 other columns in addition to the first common column).
I want to write a script to join the files by the first common column so that in the... (5 Replies)
Hi Guys,
I want to combine 2 files and and put together in 1 file . See below desired output. Any help will be much appreciated.
FILE AX 2134 101L 12345.00 22222.00 1 10
X 2134 101L 12345.00 22222.00 11 20
X 2134 101L 12345.00 22222.00 21 30
X 2134 111L 77777.00 ... (3 Replies)
I have two directories called English and Hindi. Each directory contains the same number of files with the only difference being that in the case of the English Directory the tag is
.english
and in the Hindi one the tag is
.Hindi
The file may contain either a single text or more than one text... (7 Replies)
Discussion started by: gimley
7 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)