Returns the value of EXPR with all non-"word" characters backslashed. (That is, all characters not matching /[A-Za-z_0-9]/ will be preceded by a backslash in the returned string, regardless of any locale settings.) This is the internal function implementing the \Q escape in double-quoted strings.
If EXPR is omitted, uses $_.
quotemeta (and \Q ... \E) are useful when interpolating strings into regular expressions, because by default an interpolated variable will be considered a mini-regular expression. For example:
my $sentence = 'The quick brown fox jumped over the lazy dog'; my $substring = 'quick.*?fox'; $sentence =~ s{$substring}{big bad wolf};Will cause $sentence to become 'The big bad wolf jumped over...'.
On the other hand:
my $sentence = 'The quick brown fox jumped over the lazy dog'; my $substring = 'quick.*?fox'; $sentence =~ s{\Q$substring\E}{big bad wolf};Or:
my $sentence = 'The quick brown fox jumped over the lazy dog'; my $substring = 'quick.*?fox'; my $quoted_substring = quotemeta($substring); $sentence =~ s{$quoted_substring}{big bad wolf};Will both leave the sentence as is. Normally, when accepting string input from the user, quotemeta() or \Q must be used.