Having a small Issue running a Perl scripts IF statement. - linux

Question

I created a small script in Perl and I am really new to this. I'm supposed to have a script that looks at an argument given and create a directory tree in the given argument. This part of the script works. The second part (which is the nested if statement) does not when you do not give an argument and it asks you to input a directory of your choice. I believe the nested if statement is messing up due to the $file input but I'm not entirely sure whats wrong. This is probably something really simple, but I have not been able to find the solution. Thank you in advance for the help and tips.
#! /usr/bin/perl
if ($#ARGV == -1)
{
print "Please enter default directory:";
my $file=<STDIN>;
if (-d $file)
{
chdir $file;
system("mkdir Data");
system("mkdir Data/Image");
system("mkdir Data/Cache");
print "Structure Created";
}
else
{
print "Directory does not exsist";
}
}
else
{
chdir $ARGV[0];
system("mkdir Data");
system("mkdir Data/Image");
system("mkdir Data/Cache");
print ("Structure Created");
}
print ("\n");

Answer 1

The test -d $file is failing because what is entered via STDIN also has the newline, after the string that specifies the directory name. You need chomp($file);
However, there are a few more points I would like to bring up.
Most importantly, there is repeated code in both branches. You really do not want to do that. It can, and does, cause trouble later. Instead, decide on the directory name, and then make it.
Second, there is no reason to go out to the system in order to make a directory. It is far better to do it in Perl, and there are good modules for this.
use strict;
use warnings;
use File::Path qw(make_path);
my $dir;
if (not #ARGV) {
print "Please enter default directory: ";
$dir = <STDIN>;
chomp $dir;
}
else {
$dir = $ARGV[0];
}
die "No directory $dir" if not -d $dir;
my $orig_cwd = chdir $dir or die "Can't chdir to $dir: $!";
my #dirs = map { "Data/$_" } qw(Image Cache);
my #dirs_made = make_path( #dirs, { verbose => 1 } );
print "Created directories:\n";
print "$_\n" for #dirs_made;
I build the directory list using map so to avoid repeated strings with Data/..., and for later flexibility. You can of course just type the names in, but that tends to invite silly mistakes.
I used File::Path to make the directories. It builds the whole path, like mkdir -p, and has a few other useful options that you can pass in { }, including error handling. There are other modules as well, for example Path::Tiny with its mkpath (and a lot of other goodies).
Note that with chdir you probably want to record the current working directory, that it returns, and that you want to check for error. But you don't have to chdir, if there are no other reasons for that. Just include the $dir name in the map
# No chdir needed here
my #dirs = map { "$dir/Data/$_" } qw(Image Cache);