John Lin wrote:
>
> Hi List,
Hello,
> This is probably a really simple question, but I need some help with this.
> Basically, I am searching through a directory and if something matches
> what I am looking for, then save that filename to a text file. Something
> like this:
> ===================================
> $wanted_filename='thisfilename';
>
> opendir (DIRECTORY, "/directory/");
> @filenames=readdir(DIRECTORY);
> closedir(DIRECTORY);
>
> for ($i=0; $i <= $#filenames; $i++) {
> [EMAIL PROTECTED];
> if ($wanted_filename == $filename) {
> $append_filename=$filename . ';';
> open(APPENDFILE, ">>/anotherdirectory/filename.txt");
> print APPENDFILE $append_filename;
> close(APPENDFILE);
> }
> }
> ====================================
>
> But for some reason, the IF statement did not work. In the filename.txt
> file, I am getting something like this:
>
> .;..;file1;file2;thisfilename;file3;.....
>
> Basically the IF statement did not filter out the files that I didn't
> want. The only filename that I wanted to store, if it's found in the
> directory, is "thisfilename". Any help is appreciated. Thanks.
You are using the numerical comparison operator '==' but you are comparing
strings so you need to use 'eq' instead. Also your for loop is very C-ish,
a more perl-ish loop would look like:
my $wanted_filename = 'thisfilename';
opendir DIRECTORY, '/directory' or dir "Cannot open /directory: $!";
my @filenames = readdir DIRECTORY;
closedir DIRECTORY;
for my $filename ( @filenames ) {
if ( $wanted_filename eq $filename ) {
$append_filename = $filename . ';';
open APPENDFILE, '>>/anotherdirectory/filename.txt'
or die "Cannot open /anotherdirectory/filename.txt: $!";
print APPENDFILE $append_filename;
close APPENDFILE;
}
}
If the file that you are appending to is the same for every entry in @filenames
then there is no point in opening and closing it in the loop.
my $wanted_filename = 'thisfilename';
opendir DIRECTORY, '/directory' or dir "Cannot open /directory: $!";
my @filenames = readdir DIRECTORY;
closedir DIRECTORY;
open APPENDFILE, '>>/anotherdirectory/filename.txt'
or die "Cannot open /anotherdirectory/filename.txt: $!";
for my $filename ( @filenames ) {
if ( $wanted_filename eq $filename ) {
print APPENDFILE $filename, ';';
}
}
close APPENDFILE;
Of course, you could also do it without the for loop. :-)
my $wanted_filename = 'thisfilename';
opendir DIRECTORY, '/directory'
or dir "Cannot open /directory: $!";
open APPENDFILE, '>>/anotherdirectory/filename.txt'
or die "Cannot open /anotherdirectory/filename.txt: $!";
print APPENDFILE map "$_;", grep $wanted_filename eq $_, readdir DIRECTORY;
closedir DIRECTORY;
close APPENDFILE;
John
--
use Perl;
program
fulfillment
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