Noob Question

[nick1984]

Hi guys,

I have literally started learning Perl a few days ago (using the Learning Perl O'reilly 4th edition book) and have hit a stumbling block!

I am currently attempting to get the below code to read the text from a text file and print! However I get the following error message: can't open test1.txt No such file or directory.

I have created all my scripts under: C:\Scripts\ and have also placed the test1.txt file there too!

------------------
#! /usr/bin/perl -w
use strict;


@ARGV = ("test1.txt");
while (<>) {
    chomp;
    print "It was $_ that I saw in some stooge-like file!\n";
}
------------------------

Thanks.

[Corion]

The "current directory" is not what you think it is. Perl will go looking for test1.txt in the current directory, which is not necessarily the directory the current Perl script lives in.

Most likely you are running your script like:

C:\>perl -w C:\Scripts\nick1984.pl

... which means that the "current directory" is C:\ and Perl goes looking for C:\test1.txt, and does not find it there.

Change either the current directory or move the file to a different place.

[bms]

Hello there! Well, there are a lot of ways you could go about this. I'll list three very easy to implement ones, each with a different approach

One, simply cd into the script directory and run your script from there.

cd C:\\Scripts

Two, use File::Basename so you can build an absolute path to your test1.txt file using dirname:

#!/usr/bin/env perl
 
use File::Basename;

use strict;
use warnings;

@ARGV = (dirname(__FILE__)."/test1.txt");

while(<>) {
    chomp;
    print "It was $_ that in some stooge like file!\n";
}

The above code works because your test1.txt file is located in the same directory as your script and therefore, you can use dirname with the __FILE__ variable(or $0) and simply tack on the filename to get a path to your text file.

Three, you could use an absolute path:

#!/usr/bin/env perl

use strict;
use warnings;

@ARGV = ("C:/Scripts/test1.txt");

while (<>) {
    chomp;
    print "It was $_ that I saw in some stooge-like file!\n";
}

As you can see, there is more than one way to do it. There are still more ways than I have listed, but they should be sufficient :).

[nick1984]

Thank you very much all very good ways of resolving my issue!

[davido]

If learning Perl is your goal, you're definitely on the right track, and I just wanted to congratulate you for putting in the effort in this undertaking. The book you're working your way through is a very good resource. Your syntax is valid, and others have explained the point of failure and how to overcome it. Stick with it, and welcome to the Monastery!

[aitap]

In addition to previous answers, you can use Cwd to get the current working directory.

[Laurent_R]

You obviously did not really understand the Perl syntax to open and read a file.

Try something like this:

#! /usr/bin/perl
use strict;
use warnings;

open (my $fh, "<", "test.txt") or die "Could not open test file $! \n"
+;
while (<$fh>) {
     # blah blah
}

[chromatic]

readline reads from *ARGV if you don't provide an operand.