Question about using readdir to read the files in a directory ...

[Matt]

Hello,

I am writing a script that opens needs to get a listing of files in a
directory, print that listing to a file and use that file as a quasi ftp
control file. My problem is that when I print the filenames found via the
readdir I also get the . and .. (current directory and parent directory)
written in the ftp control file which causes my script to stop since you
can't ftp . nor ..

Here's my logic ....


opendir(DON,"/don") || die "Can't opendir /don: $!";
open(DATFILELIS T,">>/data/datafiles.out") || die "Can't opendir
/data/datafiles.out: $!";
print DATFILELIST "cd /incoming\n";
print DATFILELIST "lcd /data/utech/dat\n";
while ($donefile = readdir(DON)) {
$datafile = $donefile;
$datafile =~ s/\.don/\.dat/;
print DATFILELIST "get $datafile\n";
}
print DATFILELIST "bye\n";
close(DATFILELI ST) || die "Can't close file /data/datafiles.out $!";
closedir(DON) || "Can't closedir /data/utech/don: $!";

The DATFILELIST gets the right files, but it also gets the . and .. which
causes the ftp to fail.

I wonder if my real problem is with my pattern matching. I want to match
all occurences of a file that ends in .don and rename the extension to .dat
then write that output to the DATFILELIST file. This works, but it also
includes the . and ..

Any ideas woud be much appreciated.


Thanks,


Matt

[Jürgen Exner]

Re: Question about using readdir to read the files in a directory ...

Matt wrote:[color=blue]
> Hello,
>
> I am writing a script that opens needs to get a listing of files in a
> directory, print that listing to a file and use that file as a quasi
> ftp control file. My problem is that when I print the filenames
> found via the readdir I also get the . and .. (current directory and
> parent directory) written in the ftp control file which causes my
> script to stop since you can't ftp . nor ..
>
> Here's my logic ....
>
>
> opendir(DON,"/don") || die "Can't opendir /don: $!";
> open(DATFILELIS T,">>/data/datafiles.out") || die "Can't opendir
> /data/datafiles.out: $!";
> print DATFILELIST "cd /incoming\n";
> print DATFILELIST "lcd /data/utech/dat\n";
> while ($donefile = readdir(DON)) {
> $datafile = $donefile;
> $datafile =~ s/\.don/\.dat/;
> print DATFILELIST "get $datafile\n";
> }
> print DATFILELIST "bye\n";
> close(DATFILELI ST) || die "Can't close file /data/datafiles.out $!";
> closedir(DON) || "Can't closedir /data/utech/don: $!";
>
> The DATFILELIST gets the right files, but it also gets the . and ..[/color]

Not very surprising. Those are directory entires after all, too, and you
don't remove/skip them anywhere.
[color=blue]
> which causes the ftp to fail.
>
> I wonder if my real problem is with my pattern matching. I want to
> match all occurences of a file that ends in .don and rename the
> extension to .dat then write that output to the DATFILELIST file.[/color]

Actually the pattern match is only the first step in the substitute
operator.
You got a minor issue in the replacement string. The replacement string is a
string, not an RE. Therefore there is no reason to escape the dot.
And you got a maybe significant issue in the RE. Your RE will match anywhere
in the string. If you want to match only the final extension then you must
anchor your RE: /\.don$/
[color=blue]
> This works, but it also includes the . and ..[/color]

Of course. Just as it will contain any file named any other way. Just try
creating some junk files with random names.
[color=blue]
> Any ideas woud be much appreciated.[/color]

If you want to print only specific files, then you may want to use a
condition, e.g. (untested):

if ($datafile =~ s/\.don/\.dat/) {
print DATFILELIST "get $datafile\n";
}

On the other hand the whole sections begs the question why don't you just
use $_ (agaIn, untested):
while (readdir(DON)) {
if (s/\.don/\.dat/) {
print DATFILELIST "get $_\n";
}
}

[Matt]

Re: Question about using readdir to read the files in a directory ...

Jurgen,

Thank you for the response. I did try the expression boundaries earlier but
they didn't seem to help so I kept playing around. I will definitely put
them back since I know it is better coding.

I will also work to implement the condition statement.

Thank you for your assistance.


Matt
"Jürgen Exner" <jurgenex@hotma il.com> wrote in message
news:5L9td.754$ zh7.152@trnddc0 2...[color=blue]
> Matt wrote:[color=green]
> > Hello,
> >
> > I am writing a script that opens needs to get a listing of files in a
> > directory, print that listing to a file and use that file as a quasi
> > ftp control file. My problem is that when I print the filenames
> > found via the readdir I also get the . and .. (current directory and
> > parent directory) written in the ftp control file which causes my
> > script to stop since you can't ftp . nor ..
> >
> > Here's my logic ....
> >
> >
> > opendir(DON,"/don") || die "Can't opendir /don: $!";
> > open(DATFILELIS T,">>/data/datafiles.out") || die "Can't opendir
> > /data/datafiles.out: $!";
> > print DATFILELIST "cd /incoming\n";
> > print DATFILELIST "lcd /data/utech/dat\n";
> > while ($donefile = readdir(DON)) {
> > $datafile = $donefile;
> > $datafile =~ s/\.don/\.dat/;
> > print DATFILELIST "get $datafile\n";
> > }
> > print DATFILELIST "bye\n";
> > close(DATFILELI ST) || die "Can't close file /data/datafiles.out $!";
> > closedir(DON) || "Can't closedir /data/utech/don: $!";
> >
> > The DATFILELIST gets the right files, but it also gets the . and ..[/color]
>
> Not very surprising. Those are directory entires after all, too, and you
> don't remove/skip them anywhere.
>[color=green]
> > which causes the ftp to fail.
> >
> > I wonder if my real problem is with my pattern matching. I want to
> > match all occurences of a file that ends in .don and rename the
> > extension to .dat then write that output to the DATFILELIST file.[/color]
>
> Actually the pattern match is only the first step in the substitute
> operator.
> You got a minor issue in the replacement string. The replacement string is[/color]
a[color=blue]
> string, not an RE. Therefore there is no reason to escape the dot.
> And you got a maybe significant issue in the RE. Your RE will match[/color]
anywhere[color=blue]
> in the string. If you want to match only the final extension then you must
> anchor your RE: /\.don$/
>[color=green]
> > This works, but it also includes the . and ..[/color]
>
> Of course. Just as it will contain any file named any other way. Just try
> creating some junk files with random names.
>[color=green]
> > Any ideas woud be much appreciated.[/color]
>
> If you want to print only specific files, then you may want to use a
> condition, e.g. (untested):
>
> if ($datafile =~ s/\.don/\.dat/) {
> print DATFILELIST "get $datafile\n";
> }
>
> On the other hand the whole sections begs the question why don't you just
> use $_ (agaIn, untested):
> while (readdir(DON)) {
> if (s/\.don/\.dat/) {
> print DATFILELIST "get $_\n";
> }
> }
>
>[/color]