read file with optional path

[jr8rdt]

hello

this one below works if you run the program on the same directory as a.txt

a.txt is an argument

$data_file="a.txt";
open(DAT, $data) || die("Could not open file!");

but, if you run this program from different directory, even with path being specified it won't work

say the program is aa.pl
both aa.pl and a.txt are in /local/program/directory
and from / directory

I do

perl /local/program/directoryaa.pl a.txt
it will complain that a.txt can't be found

what to do ?

 

[travs69]

You should provide the full path to a.txt in your script.
$data_file = '/path/to/a.txt';

Your open statement says $data but it should say $data_file

Also.. in your die statement.. always add $! as it will give you a lot of important information
I normally do something like:
die "Can't open file $data_file :$!\n";


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Travis - Those who say it cannot be done are usually interrupted by someone else doing it; Give the wrong symptoms, get the wrong solutions;

 

[jr8rdt]

what about if the file is an argument and I wanna be able to run it from everywhere by specifying the path

 

[travs69]

if the path is constant just make it a variable.

my $dir = '/path/to/files/';
chomp @ARGV;
my $file = ARGV[0];
open(FILE, "$dir$file") or die "Can't open $dir$file : $!\n";


Not tested

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Travis - Those who say it cannot be done are usually interrupted by someone else doing it; Give the wrong symptoms, get the wrong solutions;

 

[rharsh]

You could use File::Basename and take the path from the $0 variable.

 

[spookie]

what about if the file is an argument and I wanna be able to run it from everywhere by specifying the path

You need to handle/validate if a.txt really exist on your server by using -e file option.
e.g.

my $data_file = $ARGV[0] ;
if ( !-e $data_file )
{
 print "File a.txt does exist in given path!!" ;
 exit ;
}

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