open files.

[BeHealthy]

If I use open(fp, $FILENAME), where $FILENAME contains some
subdirectory that hasn't been set up yet, then it fails. Is there any
way I can get around this by letting the program to create the
subdirectory if needed?

 

[Paul Lalli]

If I use open(fp, $FILENAME), where $FILENAME contains some
subdirectory that hasn't been set up yet, then it fails.

open() is not used for directories, it is used for files.
perhaps you're thinking of 'opendir()'?

Is there any
way I can get around this by letting the program to create the
subdirectory if needed?

Your algorithm needs some rethinking. You're opening a directory. If
you want to use an analogy to opening files, you're opening the
directory "for reading". There is no such thing as opening a directory
"for writing". If the directory doesn't exist, even if there were a
built-in way to make open auto-create the directory, it would be
created empty. You would then have nothing to read from it.

It's time for you to tell us what you're *actually* trying to
accomplish, rather than ask for help with the method you've already
decided to use to accomplish this unknown goal.

FWIW, I don't see any particular reason you can't just do:
-d $directory_name or mkdir $directory_name
or die "Couldn't create directory $directory_name: $!\n";

(with the possible exception of the chance of a race condition)

Paul Lalli

 

[Babacio]

"Paul Lalli"

open() is not used for directories, it is used for files.
perhaps you're thinking of 'opendir()'?

I think that what the OP means is that $filename =
'/tmp/nonexists/file.txt', for example, and he wants write in it; so
if the file does not exists, the file should be created, but of course
this does not work if the directory '/tmp/nonexists/' does not exist.

May be there is something on CPAN to do that, but it's not a very
difficult thing to write anyway.

 

[Paul Lalli]

Note: The author of this message requested that it not be archived. This
message will be removed from Groups in 6 days (Oct 11, 2:38 pm).

Please don't do that. It's rude.

"Paul Lalli"


I think that what the OP means is that $filename =
'/tmp/nonexists/file.txt', for example, and he wants write in it; so
if the file does not exists, the file should be created, but of course
this does not work if the directory '/tmp/nonexists/' does not exist.

Hrm. I can see that interpretation.

May be there is something on CPAN to do that, but it's not a very
difficult thing to write anyway.

I don't know if there's a module on CPAN to do exactly that, but as you
say, it's not overly difficult to write a subroutine that will do it,
especially if we take advantage of a certain module that does exist:

#!/usr/bin/perl
use strict;
use warnings;
use File::Spec;

sub open_or_make(\$$){
my ($fh_ref, $path) = @_;
my ($v, $dirs, $file) = File::Spec->splitpath($path);
my @dirs = File::Spec->splitdir($dirs);
my $dir;
while (my $curdir = shift @dirs){
$dir = $dir ? File::Spec->catdir($dir, $curdir) : $curdir;
-d $dir or mkdir $dir or return undef;
}
open $$fh_ref, '>', $path or return undef;
return 1;
}

my $filename = 'temp/nothere/subdir/file.txt';
open_or_make my $ofh, $filename
or die "Could not open or make $filename: $!\n";
print $ofh "Hello World\n";
close $ofh;
__END__

Paul Lalli

 

[Babacio]

"Paul Lalli"

Please don't do that. It's rude.

Mmmh, I have my own opinion on this subject, sorry.
But I may make an exception for this group, in fact.
I'll think of it.

I don't know if there's a module on CPAN to do exactly that, but as
you say, it's not overly difficult to write a subroutine that will
do it,

I did not try, because I knew that you were going to do that in just a
blink. You're darn too fast!

especially if we take advantage of a certain module that does exist:

#!/usr/bin/perl
use strict;
use warnings;
use File::Spec;

Well, stupidely enough, I knew File::Basename but not File::Spec. It
seems quite more complete.

sub open_or_make(\$$){
my ($fh_ref, $path) = @_;
my ($v, $dirs, $file) = File::Spec->splitpath($path);
my @dirs = File::Spec->splitdir($dirs);
my $dir;
while (my $curdir = shift @dirs){
$dir = $dir ? File::Spec->catdir($dir, $curdir) : $curdir;

Both tricky and elegant.

-d $dir or mkdir $dir or return undef;
}
open $$fh_ref, '>', $path or return undef;
return 1;
}

my $filename = 'temp/nothere/subdir/file.txt';
open_or_make my $ofh, $filename
or die "Could not open or make $filename: $!\n";
print $ofh "Hello World\n";
close $ofh;
__END__

Paul Lalli

Bravo.

 

[Paul Lalli]

"Paul Lalli"


Mmmh, I have my own opinion on this subject, sorry.

Don't apologize. You're entitled to your opinion. Just as I'm
entitled to add you to my kill file until what I perceive as your
rudeness has ended.

Fare thee well.

 

[Babacio]

"Paul Lalli"

Don't apologize. You're entitled to your opinion. Just as I'm
entitled to add you to my kill file until what I perceive as your
rudeness has ended.

Of course, no problem for me.

 

[Brian McCauley]

my @dirs = File::Spec->splitdir($dirs);
my $dir;
while (my $curdir = shift @dirs){
$dir = $dir ? File::Spec->catdir($dir, $curdir) : $curdir;
-d $dir or mkdir $dir or return undef;
}

I think File:ath may help to simplify the above.

 

[Paul Lalli]

I think File:ath may help to simplify the above.

Whoa. Indeed it would. Why didn't I know about this module?

Many thanks, Brian.

Paul Lalli

 

[Joe Smith]

If I use open(fp, $FILENAME), where $FILENAME contains some
subdirectory that hasn't been set up yet, then it fails. Is there any
way I can get around this by letting the program to create the
subdirectory if needed?

If you are opening a file for output, you should have said so.

Just get the directory part of $FILENAME and then recursively
(or iteratively) create the parent directory if needed.
-Joe


sub mkdir_p { # Like 'mkdir -p', create parent if needed
my($parent,$success);
foreach my $dir (split '/',$_[0]) {
$parent .= $dir;
next if $parent eq '' or -d $parent;
($success = mkdir $parent,0777) or
(warn "mkdir('$parent') failed: $!\n" and return 0);
} continue {
$parent .= '/';
}
$success; # True if dir needed to be created and was created
}

....
my $newname = "$dst/$name";
my ($dir) = $newname =~ m{(.*)/};
print "mkdir $dir\n" if mkdir_p $dir and $verbose;
open my $fh,'>',$newname or die "...";