Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl Monk, Perl Meditation
 
PerlMonks  

Re: Opening multiple files

by Eliya (Vicar)
on Jan 29, 2012 at 21:41 UTC ( #950663=note: print w/ replies, xml ) Need Help??


in reply to Opening multiple files

You could do something like this:

#!/usr/bin/perl -w use strict; my @fh; # open all files for my $i (0..$#ARGV) { open $fh[$i], "<", $ARGV[$i] or die $!; } while (1) { my @lines; # read one line from each file push @lines, scalar readline $fh[$_] for 0..$#ARGV; last unless defined $lines[0]; chomp @lines; print join(",", @lines), "\n"; }
$ ./950649.pl infile1 infile2 infile3 ... > outfile

(Note that you have to use readline with "complex" file handle expressions like $fh[$i], as <$fh[$i]> wouldn't work here.)


Comment on Re: Opening multiple files
Select or Download Code
Re^2: Opening multiple files
by kielstirling (Scribe) on Jan 30, 2012 at 01:45 UTC
    Hi,

    Maybe I'm still asleep but, will this ever return out of the while loop?

    -Kiel R Stirling
      will this ever return out of the while loop?

      Yes, due to the

      last unless defined $lines[0];

      where $lines[0] becomes undef when EOF of the first file has been reached.

        arr yes that will do it .. so i am still asleep :)

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://950663]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others drinking their drinks and smoking their pipes about the Monastery: (12)
As of 2014-09-19 05:00 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    How do you remember the number of days in each month?











    Results (129 votes), past polls