diff options
| -rw-r--r-- | lib/User/pwent.pm | 2 | ||||
| -rw-r--r-- | pod/perldata.pod | 22 |
2 files changed, 23 insertions, 1 deletions
diff --git a/lib/User/pwent.pm b/lib/User/pwent.pm index f41aa2ab5a..8c059265c3 100644 --- a/lib/User/pwent.pm +++ b/lib/User/pwent.pm @@ -250,7 +250,7 @@ You may ask whether one of these was implemented on the system Perl was built on by asking the importable C<pw_has> function about them. This function returns true if all parameters are supported fields on the build platform, false if one or more were not, and raises -and exception if you asked about a field that Perl never knows how +an exception if you asked about a field that Perl never knows how to provide. Parameters may be in a space-separated string, or as separate arguments. If you pass no parameters, the function returns the list of C<struct pwd> fields supported by your build platform's diff --git a/pod/perldata.pod b/pod/perldata.pod index 3e10e6f3d4..ac444fa17c 100644 --- a/pod/perldata.pod +++ b/pod/perldata.pod @@ -750,6 +750,28 @@ C<*HANDLE{IO}> only works if HANDLE has already been used as a handle. In other words, C<*FH> must be used to create new symbol table entries; C<*foo{THING}> cannot. When in doubt, use C<*FH>. +All functions that are capable of creating filehandles (open(), +opendir(), pipe(), socketpair(), sysopen(), socket(), and accept()) +automatically create an anonymous filehandle if the handle passed to +them is an uninitialized scalar variable. This allows the constructs +such as C<open(my $fh, ...)> and C<open(local $fh,...)> to be used to +create filehandles that will conveniently be closed automatically when +the scope ends, provided there are no other references to them. This +largely eliminates the need for typeglobs when opening filehandles +that must be passed around, as in the following example: + + sub myopen { + open my $fh, "@_" + or die "Can't open '@_': $!"; + return $fh; + } + + { + my $f = myopen("</etc/motd"); + print <$f>; + # $f implicitly closed here + } + Another way to create anonymous filehandles is with the Symbol module or with the IO::Handle module and its ilk. These modules have the advantage of not hiding different types of the same name |