diff options
Diffstat (limited to 'pod/perlvar.pod')
| -rw-r--r-- | pod/perlvar.pod | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/pod/perlvar.pod b/pod/perlvar.pod index 4bd3cf9b31..ac4ebf828a 100644 --- a/pod/perlvar.pod +++ b/pod/perlvar.pod @@ -13,14 +13,20 @@ you need only say use English; -at the top of your program. This will alias all the short names to the -long names in the current package. Some even have medium names, -generally borrowed from B<awk>. +at the top of your program. This aliases all the short names to the long +names in the current package. Some even have medium names, generally +borrowed from B<awk>. In general, it's best to use the -If you don't mind the performance hit, variables that depend on the -currently selected filehandle may instead be set by calling an -appropriate object method on the IO::Handle object. (Summary lines -below for this contain the word HANDLE.) First you must say + use English '-no_match_vars'; + +invocation if you don't need $PREMATCH, $MATCH, or $POSTMATCH, as it avoids +a certain performance hit with the use of regular expressions. See +L<English>. + +Variables that depend on the currently selected filehandle may be set by +calling an appropriate object method on the IO::Handle object, although +this is less efficient than using the regular built-in variables. (Summary +lines below for this contain the word HANDLE.) First you must say use IO::Handle; @@ -33,10 +39,11 @@ or more safely, HANDLE->method(EXPR) Each method returns the old value of the IO::Handle attribute. -The methods each take an optional EXPR, which if supplied specifies the +The methods each take an optional EXPR, which, if supplied, specifies the new value for the IO::Handle attribute in question. If not supplied, most methods do nothing to the current value--except for autoflush(), which will assume a 1 for you, just to be different. + Because loading in the IO::Handle class is an expensive operation, you should learn how to use the regular built-in variables. |