name : meta_notation.pm use strict; use warnings; # A tiny private library routine which is a helper to several Perl core # modules, to allow a paradigm to be implemented in a single place. The name, # contents, or even the existence of this file may be changed at any time and # are NOT to be used by anything outside the Perl core. sub _meta_notation ($) { # Returns a copy of the input string with the nonprintable characters # below 0x100 changed into printables. Any ASCII printables or above 0xFF # are unchanged. (XXX Probably above-Latin1 characters should be # converted to \X{...}) # # \0 .. \x1F (which are "\c@" .. "\c_") are changed into ^@, ^A, ^B, ... # ^Z, ^[, ^\, ^], ^^, ^_ # \c? is changed into ^?. # # The above accounts for all the ASCII-range nonprintables. # # On ASCII platforms, the upper-Latin1-range characters are converted to # Meta notation, so that \xC1 becomes 'M-A', \xE2 becomes 'M-b', etc. # This is how it always has worked, so is continued that way for backwards # compatibility. The range \x80 .. \x9F becomes M-^@ .. M-^A, M-^B, ... # M-^Z, M-^[, M-^\, M-^], M-^, M-^_ # # On EBCDIC platforms, the upper-Latin1-range characters are converted # into '\x{...}' Meta notation doesn't make sense on EBCDIC platforms # because the ASCII-range printables are a mixture of upper bit set or # not. [A-Za-Z0-9] all have the upper bit set. The underscore likely # doesn't; and other punctuation may or may not. There's no simple # pattern. my $string = shift; $string =~ s/([\0-\037])/ sprintf("^%c",utf8::unicode_to_native(ord($1)^64))/xeg; $string =~ s/\c?/^?/g; if (ord("A") == 65) { $string =~ s/([\200-\237])/sprintf("M-^%c",(ord($1)&0177)^64)/eg; $string =~ s/([\240-\377])/sprintf("M-%c" ,ord($1)&0177)/eg; } else { no warnings 'experimental::regex_sets'; # Leave alone things above \xff $string =~ s/( (?[ [\x00-\xFF] & [:^print:]])) / sprintf("\\x{%X}", ord($1))/xaeg; } return $string; } 1