15.23 Miscellaneous

defined expr

Tests whether the lvalue expr has an actual value.

do filename

Executes filename as a Perl script. See also require in Subroutines, Packages, and Modules.

dump [ label ]

Immediate core dump. When reincarnated, starts at label.

eval { expr;... }

Executes the code between { and }. Traps runtime errors as described with eval(expr), in String Functions.

local variable

local ( list )

Creates a scope for the listed variables local to the enclosing block, subroutine, or eval.

my variable

my ( list )

Creates a scope for the listed variables lexically local to the enclosing block, subroutine, or eval.

ref expr(dagger)

Returns a true value if expr is a reference. Returns the package name if expr has been blessed into a package.

reset [ expr ]

Resets ?? searches so that they work again. expr is a list of single letters. All variables and arrays beginning with one of those letters are reset to their pristine state. Only affects the current package.

scalar expr

Forces evaluation of expr in scalar context.

undef [ lvalue ]

Undefines the lvalue. Always returns the undefined value.

wantarray

Returns true if the current context expects an array value.