print the array using command line arguements

[greatshots]

dear monks

Prog_name : print.pl

#!/usr/bin/perl

use strict;
use warnings;

my @array = ( 11,12,13,14,15);

#my @new = @array[join(",",@ARGV)];
my @new = @array[1,3];

print "@new\n";

Output :-
12 14

Changed the code as follows :-

#!/usr/bin/perl

use strict;
use warnings;

my @array = ( 11,12,13,14,15);

my @new = @array[join(",",@ARGV)];
#my @new = @array[1,3];

print "@new\n";

Output : perl print.pl 1 3

Argument "" isn't numeric in array slice at l.pl line 8.
11

Is it mandatory that all the arguements which I am passing from command line arguements should need to be converted to numbers ( if it is a number ) to print ? Is there anyother way in which, will I be able to tell my program to treat the command line arguements as integers ?

[Sidhekin]

my @new = @array[join(",",@ARGV)];

You're building a string (using join) and then using that (one) string as array indices. That is certainly not what you want.

I can only imagine you want to use your arguments themselves as array indices, in which case it's straight forward:

my @new = @array[@ARGV];

You should be getting Argument "1,3" isn't numeric in array slice and an output of 12 though, so unless you've been mixing up different runs, I'm beginning to suspect your arguments 1 3 aren't being passed to the program.

Which would be another problem.

[loris]

Hi,

Try:

my @new = @array[@ARGV];

The problem with your join is that you get a string containing commas, which cannot be treated as an integer. It will only work if you give just one index on the command line, since the join will not then introduce any commas.

HTH,

loris

[ocs]

Hi, you can also try this:

#!/usr/bin/perl -wl

use strict;

my @array = (11, 12, 13, 14, 15);

my @new = map { $array[$_] } @ARGV;

print "@new";

[Fengor]

The problem in your code is the line my @new = @array[join(",",@ARGV)]; because the first element of @ARGV is the program name Fengor writes a 100 times ksh is not perl try

#!/usr/bin/perl

use strict;
use warnings;

my @array = ( 11,12,13,14,15);

#my @new = @array[join(",",@ARGV)];
#my @new = @array[1,3];
my @new = @array[$ARGV[0],$ARGV[1]];
print "@new\n";

[lidden]

The first argument of @ARGV is not the progname
perl -wle 'print "@ARGV"' 3 4 The progname is in $0

[Fengor]

oh right.

[reneeb]

nope



#!/usr/bin/perl

use strict;
use warnings;

print "@ARGV\n";



Output:


~/entwicklung 14> perl argv.pl  1
1
(reneeb) Thu Nov 30 09:05:18 [-bash]
~/entwicklung 15> perl argv.pl  1 3
1 3
(reneeb) Thu Nov 30 09:06:06 [-bash]
~/entwicklung 16> ./argv.pl 1
1
(reneeb) Thu Nov 30 09:06:10 [-bash]
~/entwicklung 17> ./argv.pl 1 3
1 3

Edit: This is an answer to Fengor, not lidden