"Perl Programmers Reference Guide (англ.) (программ.) /19.12.1998/ " - читать интересную книгу автора not arbitrarily limit the size of your data--if you've got
the memory, Perl can slurp in your whole file as a single string. Recursion is of unlimited depth. And the tables used by hashes (previously called "associative arrays") grow as necessary to prevent degraded performance. Perl uses sophisticated pattern matching techniques to scan large amounts of data very quickly. Although optimized for scanning text, Perl can also deal with binary data, and can make dbm files look like hashes. Setuid Perl scripts are safer than C programs through a dataflow tracing mechanism which prevents many stupid security holes. If you have a problem that would ordinarily use sssseeeedddd or aaaawwwwkkkk or sssshhhh, but it exceeds their capabilities or must run a little faster, and you don't want to write the silly thing in C, then Perl may be for you. There are also translators to turn your sssseeeedddd and aaaawwwwkkkk scripts into Perl scripts. But wait, there's more... Perl version 5 is nearly a complete rewrite, and provides the following additional benefits: It is now possible to write much more readable Perl code (even within regular expressions). Formerly cryptic variable names can be replaced by mnemonic identifiers. Error messages are more informative, and the optional warnings will catch many of the mistakes a novice might make. This cannot be stressed enough. Whenever you get mysterious behavior, try the ----wwww switch!!! Whenever you don't get mysterious behavior, try using ----wwww anyway. +o Simplified grammar The new yacc grammar is one half the size of the old one. Many of the arbitrary grammar rules have been regularized. The number of reserved words has been cut by 2/3. Despite this, nearly all old Perl scripts will continue to work unchanged. 22/Jul/98 perl 5.005, patch 02 3 |
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