Beefy Boxes and Bandwidth Generously Provided by pair Networks
"be consistent"
 
PerlMonks  

Re^5: Wrong idioms (open $fh, '<', undef)

by vsespb (Hermit)
on Mar 30, 2013 at 09:04 UTC ( #1026256=note: print w/ replies, xml ) Need Help??


in reply to Re^4: Wrong idioms (open $fh, '<', undef)
in thread Wrong idioms

I mean open does not detect error if you "open" a directory. Also last code with "wantarray" and "scalar" looks useless.


Comment on Re^5: Wrong idioms (open $fh, '<', undef)
Re^6: Wrong idioms (open $fh, '<', undef)
by Anonymous Monk on Apr 02, 2013 at 08:38 UTC

    I mean open does not detect error if you "open" a directory.

    Sure it does

    $ perl -e " open $dirname, q/../ or die $!, $/, $^E, $/ " Permission denied Access is denied $ perl -e " open $dirname, q/../ or die join qq/\n/, $!,$^E,grep( { $! +{$_} } keys %! ) " Permission denied Access is denied ERROR_INVALID_DATA EMARCH_ENC_I17_IMM5C_INST_WORD_POS_X EMR_SETBRUSHORGEX EVENT_SYSTEM_CONTEXTHELPEND EACCES at -e line 1.

    Also last code with "wantarray" and "scalar" looks useless.

    No, its is not useless. You must not know perl well.

      perl -e " open $dirname, q/../ or die $!, $/, $^E, $/ "

      You must be running Windows? or? Cygwin?

      Under linux:

      perl -e " open $dirname, q/../ or die $!, $/, $^E, $/ " bash: !,: event not found
      perl -e ' open $dirname, q/../ or die $!, $/, $^E, $/ ' (no error)

      for wantarray:

      use strict; use warnings; sub array_func { my ($arg) = @_; if (wantarray) { return map { $arg } 1..3; } else { return map { $arg*2 } 1..5; } } sub uni_func { my ($arg) = @_; return wantarray ? array_func($arg) : scalar array_func($arg); } sub small_func { my ($arg) = @_; return array_func($arg) ; } print join(';', uni_func(7)); print "\n"; print scalar(uni_func(7)); print "\n"; print join(';', small_func(7)); print "\n"; print scalar(small_func(7)); print "\n"; print join(';', array_func(7)); print "\n"; print scalar array_func(7); print "\n"; __END__ prints: 7;7;7 5 7;7;7 5 7;7;7 5
      what's the point in using 'wantarray' in uni_func here?

        You must be running Windows? or? Cygwin?

        Yeah :)

        for wantarray: ... what's the point in using 'wantarray' in uni_func here?

        clarity of intent, explicitness

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1026256]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others scrutinizing the Monastery: (11)
As of 2014-07-23 07:03 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    My favorite superfluous repetitious redundant duplicative phrase is:









    Results (135 votes), past polls