untie VARIABLE Breaks the binding between a variable and a package. (See tie.) Has no effect if the variable is not tied.

unshift ARRAY,LIST unshift EXPR,LIST Does the opposite of a shift. Or the opposite of a push, depending on how you look at it. Prepends list to the front of the array and returns the new number of elements in the array. unshift(@ARGV, '-e') unless $ARGV[0] =~ /^-/; Note the LIST is prepended whole, not one element at a time, so the prepended elements stay in the same order. Use reverse to do the reverse. Starting with Perl 5.14, unshift can take a scalar EXPR, which must hold a reference to an

NAME SYNOPSIS DESCRIPTION WARNINGS EXPORTS NAME UNIVERSAL - base class for ALL classes (blessed references) SYNOPSIS $is_io = $fd->isa("IO::Handle"); $is_io = Class->isa("IO::Handle"); $does_log = $obj->DOES("Logger"); $does_log = Class->DOES("Logger"); $sub = $obj->can("print"); $sub = Class->can("print"); $sub = eval { $ref->can("fandango") }; $ver = $obj->VERSION; # but never do this! $is_io = UNIVERSAL::isa($fd, "IO::Handle"); $sub

unless These flow-control keywords are documented in Compound Statements in perlsyn.

unlink LIST unlink Deletes a list of files. On success, it returns the number of files it successfully deleted. On failure, it returns false and sets $! (errno): my $unlinked = unlink 'a', 'b', 'c'; unlink @goners; unlink glob "*.bak"; On error, unlink will not tell you which files it could not remove. If you want to know which files you could not remove, try them one at a time: foreach my $file ( @goners ) { unlink $file or warn "Could not unlink $file: $!"; } Note: unlink will not attem

unpack TEMPLATE,EXPR unpack TEMPLATE unpack does the reverse of pack: it takes a string and expands it out into a list of values. (In scalar context, it returns merely the first value produced.) If EXPR is omitted, unpacks the $_ string. See perlpacktut for an introduction to this function. The string is broken into chunks described by the TEMPLATE. Each chunk is converted separately to a value. Typically, either the string is a result of pack, or the characters of the string represent a C stru

UNITCHECK These compile phase keywords are documented in BEGIN, UNITCHECK, CHECK, INIT and END in perlmod.

NAME SYNOPSIS DESCRIPTIONcode point argument *charinfo()* *charprop()* *charprops_all()* *charblock()* *charscript()* *charblocks()* *charscripts()* *charinrange()* *general_categories()* *bidi_types()* *compexcl()* *casefold()* *all_casefolds()* *casespec()* *namedseq()* *num()* *prop_aliases()* *prop_values()* *prop_value_aliases()* *prop_invlist()* *prop_invmap()* *search_invlist()* Unicode::UCD::UnicodeVersion *Blocks versus Scripts* *Matching Scripts and Blocks* Old-style versus new-style

NAME SYNOPSIS DESCRIPTIONNormalization Forms Decomposition and Composition Quick Check Character Data EXPORT CAVEATS AUTHOR SEE ALSO NAME Unicode::Normalize - Unicode Normalization Forms SYNOPSIS (1) using function names exported by default: use Unicode::Normalize; $NFD_string = NFD($string); # Normalization Form D $NFC_string = NFC($string); # Normalization Form C $NFKD_string = NFKD($string); # Normalization Form KD $NFKC_string = NFKC($string); # Normalization Form KC (2) using fun

NAME SYNOPSIS DESCRIPTIONConstructor and Tailoring Methods for Collation Methods for Searching Other Methods EXPORT INSTALL CAVEATS AUTHOR, COPYRIGHT AND LICENSE SEE ALSO NAME Unicode::Collate - Unicode Collation Algorithm SYNOPSIS use Unicode::Collate; #construct $Collator = Unicode::Collate->new(%tailoring); #sort @sorted = $Collator->sort(@not_sorted); #compare $result = $Collator->cmp($a, $b); # returns 1, 0, or -1. Note: Strings in @not_sorted , $a and $b are interpreted a