$ alias perle
alias perle='perl -Mstrict -Mwarnings -Mautodie=:all -MCarp::Always -E'

##</code><code>##

$ perle 'use Fcntl; say O_RDONLY'
0

$ perle 'use Fcntl; say O_RDONLY; say F_NOCACHE'
Name "main::F_NOCACHE" used only once: possible typo at -e line 1.
0
say() on unopened filehandle F_NOCACHE at -e line 1.

##</code><code>##

$ perle 'use Fcntl qw{O_RDONLY F_NOCACHE}; say O_RDONLY; say F_NOCACHE'
"F_NOCACHE" is not exported by the Fcntl module
Can't continue after import errors at -e line 1.
        main::BEGIN() called at -e line 1
        eval {...} called at -e line 1
BEGIN failed--compilation aborted at -e line 1.

##</code><code>##

$ perle 'use Fcntl; use constant F_NOCACHE => 48; say O_RDONLY; say F_NOCACHE'
0
48

$ perle 'use Fcntl; use constant F_NOCACHE => 48; say O_RDONLY | F_NOCACHE'
48

$ perle 'use Fcntl; use enum qw{F_NOCACHE=48}; say O_RDONLY; say F_NOCACHE'
0
48

$ perle 'use Fcntl; use enum qw{F_NOCACHE=48}; say O_RDONLY | F_NOCACHE'
48

##</code><code>##

$ perle 'use Fcntl; use enum qw{F_NOCACHE=48}; sysopen my $fh, "dummy_file", O_RDONLY | F_NOCACHE; close $fh'