print DAT "$_\n";
[download]

print ("$_\n");
[download]

A simple ++ is not enough. You have hit the nail on the head. His code currently prints to STDOUT instead of printing to the file.

package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name
/p

The code as shown is not deleting any records. Also, the filehandle DAT is opened for writing, but never closed: close $output; should be close DAT;. But I suspect the real problem is in the line:

next if ($field[1], $field[2]) = ($delroadName, $delroadNumber);
[download]

Perhaps you meant:

next if $field[1] eq $delroadName && $field[2] == $delroadNumber;
[download]

Note that = is for assignment. To test for equality, == is used for numbers, and eq for strings.

Also note that $field[1] is the second field, as arrays start from element zero. (Your code may be correct here — I only mention this as a point to double-check.)

Hope that helps,

My code deletes all the records not just the one line I need any solutions?

Start with a description of what you think your code (del) does, and a small example (with very small input file) of how to use it (del), and then employ Basic debugging checklist (with Read this if you want to cut your development time in half! )

Fix any warnings you get, repeat

use strict   ;
use warnings ;


sub del {

    my ( $delroadName, $delroadNumber ) = @_ ;  # This line handles pa
+rams for function, 
                                                #    moved to first pa
+rt of function

    my $process_file = "data.txt";              # Variable name change
+d to reflect action - 
                                                #    This kind of thin
+g can mess things up later. 

    my @data ;
    { 

    # Adding additional scope to prevent missuse or error use of fileh
+andle.

    open( my $data_file_handle, '<', "$process_file" )   # Changed to 
+3 param open and replaced bareword file handle.
        or die("Can't open file: $process_file");        # Changed || 
+to 'or' in case someone removes brackets for 'open'
                                                             #   Also 
+added file name to error message.         

    @data = <$data_file_handle> ;               # NOTE: 'my' removed t
+o ensure scope. 
    close( $data_file_handle );
    }



    chomp( @data ); 

    open( my $out_file_handle,'>', $process_file ) 
    or die("Can't open file: $process_file"); # Modified as above.

    foreach my $line_from_file ( @data ) {                     # Chang
+ed from for to foreach removed dependence on $_ 
    my @field = split( /\:/, $line_from_file );           

    # next if( ( $field[0] eq $delroadName ) && ( $field[1] == $delroa
+dNumber ) ); 
    # Added brackets and changed $field[0] in both to [0] and [1]
    next if( ( $field[0] eq $delroadName ) && ( $field[1] == $delroadN
+umber ) ); 
    print $out_file_handle $line_from_file, "\n";         # Modified t
+o print to file handle - Else the file will be truncated
                                                #   Since you are open
+ is with '>' and will remain blank. 
    }

    # close $output;
    close $process_file;  # You want to close the file handle, not the
+ string.

}
[download]

Update: Corrected stupid mistake as pointed out by tobyink below.

Thanks for all of the information and the revised code worked it did delete the entries in the file and when i opened the data.txt file here was the input:




delcarEntry=HASH(0x191920c)
delcarEntry=HASH(0x191920c)
delcarEntry=HASH(0x191920c)

Try:

print $out_file_handle $line_from_file, "\n";
[download]

You're currently printing out the variable $_ which isn't being defined by any of the code you posted (but is being defined somewhere else to point to an object of some kind).

package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name