Comparing the number of rows in two files

[Dudek]

Hi there,

How can i compare the number of rows in two files (UNIX)?

Basically what i need to do is:

if (compare number of rows ('file1', 'file2')==0)
{
do something;
}

so is there any way to do the comparison of the two files to see whether they have the same number of rows?

TIA
JD

 

[MikeLacey]

a simple way to do this would be to use the standard 'wc' utility

in your compare_number_of_rows() sub call 'wc -l' on each file, reading the results into a variable, like this:

my $f1_wc = `wc -l $file1`;
my $f2_wc = `wc -l $file2`;

then you can examine the two variables, $f1_wc and $f2_wc,and return either 1 (true) or 0 (false)
[tt]
use strict;
use warnings;

sub do_something(){
print "equal\n";
}

sub compare_number_of_rows($$){
my ($file1, $file2) = @_;

$_ = `wc -l $file1`;
my ($lc1, undef) = split();

$_ = `wc -l $file2`;
my ($lc2, undef) = split();

if($lc2 == $lc1){
return(1); # true
} else {
return(0); # false
}

}

if (compare_number_of_rows('file1', 'file2')){
do_something();
}
[/tt]
Mike
"Experience is the comb that Nature gives us after we are bald."

Is that a haiku?
I never could get the hang
of writing those things.