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20000816: varget problem: segmentation fault

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  • Subject: 20000816: varget problem: segmentation fault
  • Date: Wed, 16 Aug 2000 12:44:34 -0600
Bill,

> From: "William R Moninger" <address@hidden>
> Subject: problem with perl netCDF
> Organization: NOAA/FSL
> Keywords: 200008161736.e7GHaON16062 netCDF Perl

The above message contained the following:

> Hello,
> 
> I am trying to do a NetCDF::varget, and this works fine unless I provide
> an argument to my perl script.
> 
> The problematic script is below.  I can provide the netCDF file (which
> is short) if you wish.

Offhand, I don't see anything wrong.  Would you please send me an
ncdump(1) of the netCDF file.

> I'll appreciate any help you can provide.
> 
> -Bill
> 
> This script generates a segmentation fault in the varget call:
> 
> #!/usr/local/perl5/bin/perl -T
> 
> #redirect stderr to stdout so we can see err msgs on the web
> $|=1;  #force flush of buffers after each print
> open (STDERR, ">&STDOUT") || die "can't dup stdout ($!)\n";
> 
> use strict;
> use NetCDF;
> NetCDF::opts(2);              # NC_VERBOSE = 2
> my $n_hours = $ARGV[0] || 1;
> #$n_hours = 1;  # NO ERROR IF THIS LINE IS UN-COMMENTED
> print "n_hrs is $n_hours\n";
> my $endSecs = time() - 3600;
> print "Args are @ARGV\n";
> my $startSecs = $endSecs - 3600*$n_hours;
> 
> my $secs = $startSecs;
> my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) =
>     gmtime($secs);
> #get pirep file for this hour
> $year %=100;
> $mon++;
> my $filename = sprintf("pireps/%02d%02d%02d%02d00.ncf",
>                      $year,$mon,$mday,$hour);
> print "file is $filename\n";
> my $ncid=-1;
> no strict;
> my $read_mode = NetCDF::READ;
> use strict;
> $ncid =  NetCDF::open("$filename",$read_mode);
> if($ncid != -1) {
>     my $dname="xxxxxxxxxxxxxxxxxxx";
>     my $dlen=-1;
>   NetCDF::diminq($ncid,0,$dname,$dlen);
>     my $n_pireps = $dlen;
>     print "Opened $filename with $n_pireps pireps\n";
>     my $date_id = NetCDF::varid($ncid,"date");
>     my @n_to_read = ($n_pireps);
>     my @start_read = (0);
>     my @dates = ();
>     print "got here\n";
>   NetCDF::varget($ncid,$date_id,\@start_read,
>                \@n_to_read,\@dates);
>     print "dates are @dates\n";
>   NetCDF::close($ncid);
> }
> 
> -- 
> William R. Moninger  NOAA, Forecast Systems Laboratory
> tel: 303-497-6435    email: address@hidden   
> fax: 303-497-3329    http://www-frd.fsl.noaa.gov/~moninger/

Regards,
Steve Emmerson   <http://www.unidata.ucar.edu>