Solved Posts by d5e5

d5e5 109 Master Poster

12 Years Ago

Re: Search a file containing multiple headers and data

my $save_header; #define g̶l̶o̶b̶a̶l̶ lexical variable whose scope includes entire script

my @flds = split;#r̶e̶a̶d̶ ̶f̶i̶l̶e̶ ̶c̶o̶n̶t̶e̶n̶t̶s̶ ̶i̶n̶t̶o̶ ̶a̶n̶ ̶a̶r̶r̶a̶y̶ Equivalent to my(@flds) = split(' ', $_, 0);

print "\n" if $save_header and $_ ne $save_header; #print newline i̶n̶ ̶b̶o̶t̶h̶ ̶c̶a̶s̶e̶s̶ before printing a new header (blank line between groups)

$save_header = $_;#assign the value of the current header ($_) to a variable so we can compare in the future to know if we are about to start another header group (i.e. whether we want a blank line separating previous group from current group.

sub findit {#sub routine -opens file and returns m̶a̶t̶c̶h̶e̶d̶ ̶e̶l̶e̶m̶e̶n̶t̶s̶ true (non-zero value) if parameter found in file, false (0) if not found in file.

return(1) if index($_,$word) > -1;# c̶h̶e̶c̶k̶ ̶i̶f̶ ̶s̶e̶a̶r̶c̶h̶ ̶w̶o̶r̶d̶ ̶f̶r̶o̶m̶ ̶i̶n̶p̶u̶t̶ ̶f̶i̶l̶e̶2̶.̶t̶x̶t̶ ̶m̶a̶t̶c̶h̶e̶s̶ ̶a̶ ̶p̶a̶r̶t̶i̶c̶u̶l̶a̶r̶ ̶i̶n̶d̶e̶x̶ ̶e̶l̶e̶m̶e̶n̶t̶ ̶i̶n̶ ̶i̶n̶p̶u̶t̶ ̶f̶i̶l̶e̶1̶ If the word is NOT found in the current record the index will give a value of -1. If the word is found, the index will give a number indicating where in the current record the word was found. I can't explain it better than http://perldoc.perl.org/functions/index.html

Software Development perl seo

d5e5 109 Master Poster

12 Years Ago

Re: Search a file containing multiple headers and data

You could also try the following:

#!/usr/bin/perl
use strict; 
use warnings; 

open my $fh, '<', 'input1.csv' or die "Failed to open input1.csv $!";
my $save_header;
while (<$fh>){
    my @flds = split;
    if (@flds == 1){
        s/\s//g;
        print "\n" if $save_header and $_ ne $save_header;
        print "$_:\n";
        $save_header = $_;
    }
    else{
        print "$flds[0]\n" if findit($flds[0]);
    }
}

sub findit {
    my $word = shift;
    open my $fh, '<', 'input2.csv' or die "Failed to open input2.csv $!";   
    while (<$fh>) {
        return(1) if index($_,$word) > -1;
    }
}

Software Development perl seo

d5e5 109 Master Poster

12 Years Ago

Re: Search a file containing multiple headers and data

Look closely at lines 16 - 17.

                my $Header;
                $hash{$Header} = $_;

You declare a lexical variable called $Header and assign no value to it, so its value is undefined. Then you use $Header (whose value is undefined) as a key to $hash. In effect you are assigning all the header values to one key (key = undef) in your hash. Each value replaces the previous value because you always use the same undefined key.

Software Development perl seo

d5e5 109 Master Poster

12 Years Ago

Re: Quick question: Perl and Sampled Data

The following script creates a table (if it doesn't already exist) and saves all the image names (extension included) and the directory names.

#!/usr/bin/perl
use strict; 
use warnings; 
use DBI;
use File::Glob ':glob';
use File::Basename;

my $dbh=DBI->connect('dbi:mysql:daniweb','david','dogfood') ||
   die "Error opening database: $DBI::errstr\n";

$dbh->do("CREATE TABLE IF NOT EXISTS images (id INT NOT NULL AUTO_INCREMENT,
                                i_name VARCHAR(64),
                                i_dir VARCHAR(100),
                                PRIMARY KEY (id))");

my $sth = $dbh->prepare("insert into `images` (i_name, i_dir) values (?, ?)")
             or die "prepare failed: " . $dbh->errstr();  


my @files = </home/david/Pictures/*>;
foreach (@files) {
    my($filename, $dir) = fileparse($_);
    $sth->execute($filename, $dir) or die "execute failed: " . $sth->errstr(); 
}

# Close connection
$sth->finish();
undef($dbh);

Software Development mysql perl

2teez commented: Nice one +3

d5e5 109 Master Poster

12 Years Ago

Re: running functions perl (basic)

I should add that experienced programmers do not require their users to memorize the real names of all their subroutines to use as command-line arguments at run-time. Make the command-line arguments short, easy to remember and spell. Use a hash or an if-elsif-else statement to associate the command-line arguments with the name of the appropriate function or subroutine. If the argument value does not correspond to any of the expected values, your script should display a warning or error message.