Re: reading files from a directory

Get rid of the whitespace surrounding your IN filehandle. Change:

while ( < IN > ){
[download]

To:

while ( <IN> ){
[download]

B::Deparse can shine a little more light upon the situation (Tip #6 from the Basic debugging checklist):

perl -MO=Deparse 867882.pl

my $dir = 'input_files';
die "can't opendir $!" unless opendir DIR, $dir;
while (defined(my $file = readdir DIR)) {
    do {
        print "The directory and file are $dir/$file\n";
        die "Can't open input file $!" unless open IN, "< $dir/$file";
        use File::Glob ();
        while (defined($_ = glob(' IN '))) {
            print $_;
        }
    };
}
closedir DIR;
[download]

Here is an explanation from perlop:

Even <$x > (note the extra space) is treated as glob("$x ") , not readline($x).

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Re^2: reading files from a directory by kevyt (Scribe) on Oct 28, 2010 at 05:49 UTC
Thanks very much. I am not able to print the contents of the file. I'll read about glob and the explanation in the perlop. Thank you! `my $dir = 'input_files'; die "can't opendir $!" unless opendir DIR, $dir; while (defined(my $file = readdir DIR)) { do { print "The directory and file are $dir/$file\n"; die "Can't open input file $!" unless open IN, "< $dir/$file"; use File::Glob (); while (defined($_ = glob(' IN '))) { print $_; } }; } closedir DIR;` [download] Output `perl create_indivo_schemas.pl Name "main::IN" used only once: possible typo at create_indivo_schemas +.pl line 18. The directory and file are input_files/allergies INThe directory and file are input_files/immunizations INThe directory and file are input_files/.. INThe directory and file are input_files/.` [download]	[reply] [d/l] [select]
Re^2: reading files from a directory by kevyt (Scribe) on Oct 28, 2010 at 06:01 UTC
I got it thanks! This will help with something called Indivo. http://wiki.chip.org/indivo/index.php/Schemas `while (defined($_ = glob(' IN '))) { print "Hello $_"; } while (<IN>){ print "Bye " . $_ ; }` [download] I need to read about glob because I don't understand that line. Which print statement has better style? Should I use the . (join) in a print? Thanks, Kevin	[reply] [d/l]
Re^3: reading files from a directory by kcott (Archbishop) on Oct 28, 2010 at 06:34 UTC
There's no need to concatenate arguments to print as that function takes a list. In fact, you're actually requesting additional processing: do the concatenation and then do the print. Even worse, if you concatenate multiple arguments you're performing multiple operations; in sort of pseudocode: print A.B.C.D performs A.B, then AB.C, then ABC.D, then print ABCD, while print A,B,C,D is one operation. As far as style is concerned, I'd say do whatever is easiest to read and maintain. `print "X ", $_, "\n";` and `print "X $_\n";` are equally valid but, as mentioned above, avoid `print "X " . $_ . "\n";`. I note there's a few places where you haven't included a newline (`\n`) at the end of your print statement. In case you didn't know, `print` doesn't automatically add one for you; say, on the other hand, does. -- Ken	[reply] [d/l] [select]