Hello,

I'm reading a netCDF file to extract a timeseries using a command line named ncks.

I dump its output in a temporary file and then I read the temporary file to extract the values and push them into an array.

Is there a way to store in memory the extracted records (@tmplines in the code below) without writing them on a temporary file?

Since I have to call the subroutine thousands of times I imagine that it would speed up things.

Thanks for any suggestion and best regards.

use strict;
use IPC::Run qw( run );
use Tie::File;
use Fcntl 'O_RDONLY';

# ... cut ...

my @ts = get_time_series(File=>$ncfile,Variable=>$ncvar,Id=>$nc_id);

# ... cut ...

sub get_time_series {

    my %args = @_;
    my $file = $args{File};
    my $variable = $args{Variable};
    my $id = $args{Id};
    my $tmpfile = "$id.tmp";

# Example:
# ncks -v vmro3 -d station,1,1 myfile.nc | grep "station\["
#

    my $command = qq(ncks -v $variable -d station,$id,$id $file | grep
+ \"station\\[\" > $tmpfile);
    run $command;

# This will write in file the following records:
#station[3385]=3386
#time[0]=3287.02083333 station[3385]=3386 vmro3[3385]=1.53524e-08 mole
+ mole-1
#time[1]=3287.0625 station[3385]=3386 vmro3[7513]=1.55109e-08 mole mol
+e-1
#time[2]=3287.10416667 station[3385]=3386 vmro3[11641]=1.56481e-08 mol
+e mole-1

    my @ts;
    tie my @tmplines, 'Tie::File', $tmpfile, mode => O_RDONLY;
    foreach my $ii (1..$#tmplines) {
        my $line = $tmplines[$ii];
        my @pa = anytrim(split(/\s/,$line));
        my ($dummy,$value) = split(/=|\s/,$pa[2]);
        push @ts, $value;
    }

    unlink $tmpfile or die "$tmpfile: $!";
    return  @ts;
}

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In reply to Execute a command line and save in memory its output by Anonymous Monk

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