The idiom I've normally used is more along the lines of something like this; call open then use constants from Errno to figure out from !$ what specifically went wrong and give more detailed advice. You can also use a variation on this to (e.g.) try and open a file for reading and fall back to another default location if !$ == ENOENT because it didn't exist; (EDIT) or you don't care if it didn't exist, but other errors you do want to bring to the user's attention.
use Errno qw( :POSIX );
use Log::Log4perl;
## ...
if( open( my $fh, q{<}, $filename ) ) {
my $frobulated_data = {};
## process with $fh
close( $fh );
return $frobulated_data;
} else {
if( $! == ENOENT ) {
ERROR( qq{Couldn't find file '$filename': $!} );
} elsif( $! == EACCES ) {
ERROR( qq{Problems with permissions for '$filename': $!} );
} elsif( ## whatever else specific you want to handle ... ) { #...
} else {
ERROR( qq{Problem opening '$filename': $!} );
}
return;
}
The cake is a lie.
The cake is a lie.
The cake is a lie.