Certainly learning

[monk2b]

The first perl scripts that I wrote started out:

print "Enter blah blah blah\n";
$device_id = <STDIN>;

Which was okay because I didn't have very many devices to keep track of.Then I learned:

$device_id = shift(@ARGV);

And this was much better ,I could call the script and input the argument at the same time.I now have even more devices and I need to automate the process even more.Can someone point out a better way to do this.What I need to do is read from a file where each line will contain 10 digits and nothing else. Then I will place each 10 digit number in as an argument.I hope I have explained my question well enough Thanks in adance for all of the help

monk2b

[Adam]

I think you already understand the tools, so I will just point you in the right direction. You want to open the file and read each line from it. Do this thusly:

use strict; # ALWAYS!

my $filename = 'devices.txt'; # Hardcode the filename.
                              # you could get the filename off the
                              # command line using shift, but be
                              # aware of the consequences of your
                              # actions.

open FILEHANDLE, $filename or die "Failed to open '$filename', $!";

while( <FILEHANDLE> ) # Read the file one line at a time.
{
    chomp;
    m/\d{10}/ or warn "Unknown arg '$_', skipping\n" and next;
    
    # Process the device numbered $_
}

close FILEHANDLE;

Code is untested, but that is okay. It is meant to point you in the right direction, not solve everything... thats what they pay you to do.

[mirod]

This is really basic stuff, and you should really grab a book (Learning Perl or Programming Perl for example) or even have a look at the docs.

Now for the task at hand just use:

#!/bin/perl -w
use strict;

my $file= shift or die "usage $0 <file>";

open( FILE, "<$file") or die "cannot open $file: $!";

while( my $device_id= <FILE>)
  { chomp $device_id; # removes the end of line
    unless( $device_id=~ /^\d{10}$/)
      { die "invalid device id: $device_id"; }
    # do your stuff here
  }

Just make sure you understand what the code does before and why you should write it along those lines before using it.

Update: Oh my god! There is no review for Programming Perl in the review section, link removed. Somebody _please_ post a review!

[Adam]

Update: Oh my god! There is no review for Programming Perl in the review section, link removed. Somebody _please_ post a review!

Done.

[redcloud]

Pass the filename on the command line, and then do

while(<>) {
    # Inside the loop, $_ will contain each ten-digit number in turn
}

[davorg]

But wouldn't

my @devices = <>;

Be a little simpler?

--
<http://www.dave.org.uk>

"Perl make the fun jobs fun
and the boring jobs bearable" - me

[monk2b]

Thanks

[redcloud]

More like:

open(BLAH_HANDLE, blah_file) or die blah blah blah;
while(<BLAH_HANDLE>) {
    my $device_id = $_;    
    system "blah blah blah $device_id";
}
close(BLAH_HANDLE);