Beefy Boxes and Bandwidth Generously Provided by pair Networks
go ahead... be a heretic
 
PerlMonks  

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
It needs a few lines of Perl code only:
use Modern::Perl qw/2014/; use File::Find::Iterator; my $find = File::Find::Iterator->create( dir => ['d:/Perl/scripts'], filter => +\&find ); open my $FH_OUT, '>', './results.CSV' or die "Could not open results f +ile - $!"; while ( my $file = $find->next ) { open my $FH_IN, '<', $file or die "Could not open $file - $!"; say $FH_OUT join ', ', ( split /,/ )[ 0, 2 ] while (<$FH_IN>); } sub find { /GENES\d+\.csv/; }
I tested it with 1000 files of 1000 lines of 10 fields each: Extracting the first and third column and saving them in the results file took 47 seconds on my ASUS tablet with a 1.33 GHz Intel ATOM Z3740 (4 core) processor. I call that very efficient.

CountZero

A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

My blog: Imperial Deltronics

In reply to Re: Is there any efficient way i can take out a specific column from hundreds of files and put it in one file? by CountZero
in thread Is there any efficient way i can take out a specific column from hundreds of files and put it in one file? by coolda

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible editor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others imbibing at the Monastery: (8)
As of 2021-05-12 11:38 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    Perl 7 will be out ...





    Results (126 votes). Check out past polls.

    Notices?