perl error message

[Jeff Picton]

hello

I am trying to find out an error with a perl filehandle. I have opened the file with a valid filehandle and closed it but it tells me the file is still open.

Any suggestions ?

[Fred Ruffet]

Hi !

Could you please send us output from your script and the part that open/close the file ?

Thanks,

Fred

[Jeff Picton]

Hi

The following is a code snippet :-

$filename=$file_name{$header[7]};

$file_name is a hash list

mkdir ("temp",0775);

open (FILE2, "> temp/$filename");
binmode (FILE2);
print FILE2 $data;
close (FILE2);
}

Jeff

[Fred Ruffet]

And what about the error ? What does it says exactly ?

Fred

[Jeff Picton]

Hi

The error to stdout as follows :-

print() on closed filehandle main::FILE2 at ./expand_SIGWX.pl line 179.
print() on closed filehandle main::FILE2 at ./expand_SIGWX.pl line 179.
print() on closed filehandle main::FILE2 at ./expand_SIGWX.pl line 179.
expand_SIGWX.pl: Info: Completed. Number of warnings = 0

hth

[Fred Ruffet]

Error tells that you want to print after close.
Isn't your close statement in a loop where it shouldn't be ? I see :
close (FILE2);
}
Shouldn't it look like :
}
close (FILE2);
?

Regards,

Fred

[Jeff Picton]

Hi Fred

You have got the gist of the problem as I would have to post the whole code for full analysis.

Cheers

Jeff

[Fred Ruffet]

Can't you post it as an attachement ?

Fred

PS : Excuse my bad english : "gist" ?

[Jeff Picton]

Here is the full program attached

[Jeff Picton]

Hi

The reasons for this is that I am running from a test environment and the filename /temp/$filename is not created. As you see there is a hashed out comment referring to the existence of temp/$filename.

[Fred Ruffet]

Labels always seemed bad things to me. IMHO you should better use a return value in contruct_filename, and execute read_write_data in main loop only if return code is good...

Regards,

Fred

[R. Allan Hicks]

try changing your open statement to

open (FILE2, "> temp/$filename") or
die "Cannot open $filename";

In looking for the simpler solution, I was asking myself "Self, what would happen if the file didn't actually open?"

Seriously, IHMO any open ought to have an or die or carp or something to give you a file open indication. Should you have to misfortune to pick a directory or a filename that you don't have write permissions.

--Good Luck

[Hein van den Heuvel]

>> The error to stdout as follows :-
>> print() on closed filehandle main::FILE2 ...

'Clearly' it is the open that failed, not the close as initially reported.

You MUST test the open status, otherwise it will bite you later (now) in more obscure ways.

You must do so both for your input and for your output file. IMHO doing a -e existance tests is almost pointless (for input. For output it has value).
What really counts is whether you can open it, and what better way to find out about that then to actually try to open it!

So use
open (FILE1, "< $input_file") || die "Open for input $input_file";

and:
open (FILE2, "> temp/$filename") || die "Create temp/$filename";



fwiw,
Hein.

[Jeff Picton]

Hello

The $filename is not being created. Can anyone explain what the outcome of the following is ?

if ($header[7] ne 0 && $header[7] ne "") {
$filename=$file_name{$header[7]};

If the array @header contains the following values ?

0, 256
1, 2004
2, 7
3, 21
4, 16
5, 0
6, 291840
7, 6
8, 0
9, 0
10, 0
11, 0
12, 0
13, 0
14, 3
15, 1254
16, 0
17, 0
18, 0
19, 0
20, 0
21, 3
22, 0
23, 0
24, 0
25, 0
26, 0
27, 0
28, 0
29, 0
30, 0
31, 0
32, 0
33, 0
34, 0
35, 0
36, 0
37, 0
38, 0
39, 0
40, 0
41, 0
42, 0
43, 0
44, 0

and the $file_name is a list in a hash :-

%file_name=(
"JUFE00_YYYYMMDDHH.BUFR" => 2,
"JUVE00_YYYYMMDDHH.BUFR" => 5,
"JUBE99_YYYYMMDDHH.BUFR" => 6

Cheers

Jeff

[Fred Ruffet · Accepted solution]

I don't know what it will do exactly, but $header[7] will return 6, and $file_name{$header[7]} will not return what you want.

I imagine that you want as a filename the key of the hash that corresponds to the value returned by $header[7]. To get that, you must access the hash by value. To do that, have a look at http://www.perldoc.com/perl5.8.4/pod/perlfaq4.html#How-do-I-look-up-a-hash-element-by-value-
But maybe, you'd better create your hash another way or use an array.

Regards,

Fred