in reply to Passing an array to a subroutine

You pretty much had it right before... 
   #open(FILE, my $aref); #or die "Cannot open: $file\n";

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except your my $aref in the open is overriding the
my ($aref} = @_;
at the head of your subroutine, so aref in the open is undef... do 
open(FILE, $aref) or die "Cannot open: $file\n"; 
$line = <FILE>;

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and you should be golden

<> works on @ARGV, not @_... if there is nothig it @ARGV it will read from STDIN

Update oh yes, the while loop would also use <FILE> instead of <>

                - Ant

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Re: Re: Passing an array to a subroutine
by gisrob (Novice) on Jul 31, 2001 at 19:38 UTC
    Thanks. I changed the code as you suggested, but my output files are empty. I ran this under the debugger with a break at that sub routine. When I type p @_ I get all the values in the array, but then p $aref is empty, and the rest of the routine, while it runs, is running on empty data. Thoughts? 
     
sub subgen {
        my $aref = @_;
    my($cur_segno) = 0;
    my(@sst) = ();
    
        open(FILE, $aref); #or die "Cannot open: $file\n";
    
    my $hdr = <FILE>; #read in the first line 
    chomp $hdr;
    my @colnames = split /, ?/, $hdr; #split the header into an array
    
    open GENFILE, '>genfile.txt';
        open INFOFILE, '>infofile.txt';
    
    my $sst_mean;
    my %fronts;
    
        while (<FILE>) {
<snip>

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[reply]
[d/l]
      hmmm keep the () around your my $aref line... 
      my ($aref) = @_;
#or do
my $aref = $_[0];
#or 
my $aref = shift;

      [download]
      shift defaults to shift the first value off @_ if you don't supply an array argument.

                      - Ant

[reply]
[d/l]
        Here's the current code. When I run it under the debugger, all is well until I get to the my $hdr line. When I step through this and (in the debugger) type p $hdr, it returns nothing; the same is true when I type p @colnames even though p $data returns the whole data array. I'm new at this, so I don't really understand how the FILEHANDLEs work. Even though this syntax seems correct, it doesn't seem to really open that array. I'm lost. 
        sub subgen {
        my($data) = shift;
    chomp($data);
    my($cur_segno) = 0;
    my(@sst) = ();
    
        open(FILE, $data); # or die "Cannot open: @data\n";
    
    my $hdr = <FILE>; #read in the first line 
    chomp $hdr;
    my @colnames = split /, ?/, $hdr; #split the header into an array

        [download]
[reply]
[d/l]

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