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6.6. cmp_ok( this, op, that, name);

compares with anything

Example 6-4. examples/intro/cmp_ok.t

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

use Test::More tests => 2;

my $start = time;
wait_for_input_with_timeout(3);
my $end = time;

cmp_ok $end - $start, ">=", 2, "process was waiting at least 2 secs";
cmp_ok $end - $start, "<=", 3, "process was waiting at most 3 secs";

sub wait_for_input_with_timeout {
    sleep rand shift;
}
$ perl cmp_ok.t 
not ok 1 - process was waiting enough
#     Failed test (cmp_ok.t at line 7)
#     '0'
#         >=
#     '2'
ok 2 - process was waiting enough
1..2
# Looks like you failed 1 tests of 2.

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