how to write a subroutine content into a file

[Pal-Cod3r]

I tried to make a script that write a subroutine content into a file but when i run it i received in the file:
1
and the code could be like this:

sub doit{
print "How are you?\n";
}
open (FILE, ">files.txt");
print FILE &doit;
close(FILE);


what is the wrong in this code and what shall i do to receive a word (How are you?) in the files.txt
Please answer my question .
Best Wishes.

[moritz]

You call a subroutine that prints something to the default output handle, and returns 1 (because the print was successful). Then you write that 1 into FILE, which is opened to 'files.txt'.

If you want the string "How are you?\n" to be end up in the file, you need to write

print FILE "How are you?\n";

Or something along the lines of

open my $file, '>', 'files.txt';
select $file; # print to $file by default
doit();
close $file;
select STDOUT; # print to STDOUT again by default

[mrstlee]

    sub doit{
     return "How are you?\n";
    }
    open (FILE, ">files.txt");
    print FILE &doit;
    close(FILE);

Or

    sub doit{
     my $handle = shift;
     print $handle "How are you?\n";
    }
    open (FILE, ">files.txt");
    doit(*FILE);
    close(FILE);

Or .. lots of ways.

[MVS]

A simple way to correct your sample code would be to replace:

print "How are you?\n";

with:

return "How are you?\n";

Now, your subroutine is returning a string, so your print statement below will print the string itself rather than the results of your successful print statement.

Edit: Oops, I didn't see the reply above until after I posted this.

[ansh batra]

it might be funny but i thought Pal-Cod3r have diff requirement.



sub doit{
 print "How are you?\n";
 $x=1+1;
 print "$x\n";
}
open(FILE,"<monkss.pl");
@lines=<FILE>;
close(FILE);
open (FILE, ">files.txt");
$flag=0;
foreach $line(@lines)
{
 if($line =~ /doit\{/)
 {
  $flag=1;
 }
 if($flag)
 {
  print FILE $line;
 }
 if($line=~ /\}/)
 {
  $flag=0;
 }
}
close(FILE);


contents of file.txt

sub doit{
 print "How are you?\n";
 $x=1+1;
 print "$x\n";
}

[choroba]

Or, similarly:

#!/usr/bin/perl

use warnings;
use strict;

sub doit {
    print "How are you?\n";
}

seek DATA, 0, 0;

while (<DATA>) {
    print if /^sub doit {/ .. /^}/
}

__DATA__

[aquinom]

The question has already answered but I thought I would contribute something nonetheless: don't use &subroutine notation anymore, it's antiquated perl and can cause unexpected problems. simply "print doit(*FILE)" as in one of the answers would suffice.

[jeffthewookiee]

If &subroutine is antiquated Perl, what's the preferred way to reference a sub?

[ww]

Have you read the most basic documentation, perldoc perlsub?

And if that's insufficiently clear, try the subroutine section of Tutorials ...for the content itself, and for the experience of trying to answer your own questions.