print"enter the input directory path:\n";
chomp($indir=<STDIN>);
print"enter the events directory path:\n";
chomp($evdir=<STDIN>);
print"enter the output directory name:\n";
chomp($tmpdir=<>);
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Why do you use <STDIN> for the first two variables and <> for the third?

opendir(DIR,".") or die "$!";
my @files=readdir DIR;

close DIR;
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You have to use closedir to close a directory handle opened with opendir.

open evein,$ever or die $!;
flock(evein, LOCK_EX) or die "Cannot lock - $!";  
while (<evein>)
{
chomp;
next unless length;
my ($key,$value)=split /===/,$_;
$result{$key}=$value;
}
close(evein);
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The value of $ever doesn't change inside this loop so this code should be outside the loop where $ever is set.

open evein,$ever or die $!;
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You are trying to open 'events.txt' from a directory entered by the user.    If the user uses a relative path then your program won't be able to find it.    You should give the user more information than just the contents of $!.

flock(evein, LOCK_EX) or die "Cannot lock - $!";
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You can't LOCK_EX a file opened only for input, only for output.

while(<fln>)
{
my ($line)=$_;
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That is usually written as:

while ( my $line = <fln> )
{
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