.\" Automatically generated by Pod::Man v1.34, Pod::Parser v1.13 .\" .\" Standard preamble: .\" ======================================================================== .de Sh \" Subsection heading .br .if t .Sp .ne 5 .PP \fB\\$1\fR .PP .. .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. | will give a .\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used to .\" do unbreakable dashes and therefore won't be available. \*(C` and \*(C' .\" expand to `' in nroff, nothing in troff, for use with C<>. .tr \(*W-|\(bv\*(Tr .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' 'br\} .\" .\" If the F register is turned on, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . nr % 0 . rr F .\} .\" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .hy 0 .if n .na .\" .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2). .\" Fear. Run. Save yourself. No user-serviceable parts. . \" fudge factors for nroff and troff .if n \{\ . ds #H 0 . ds #V .8m . ds #F .3m . ds #[ \f1 . ds #] \fP .\} .if t \{\ . ds #H ((1u-(\\\\n(.fu%2u))*.13m) . ds #V .6m . ds #F 0 . ds #[ \& . ds #] \& .\} . \" simple accents for nroff and troff .if n \{\ . ds ' \& . ds ` \& . ds ^ \& . ds , \& . ds ~ ~ . ds / .\} .if t \{\ . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' .\} . \" troff and (daisy-wheel) nroff accents .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V' .ds 8 \h'\*(#H'\(*b\h'-\*(#H' .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#] .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H' .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u' .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#] .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#] .ds ae a\h'-(\w'a'u*4/10)'e .ds Ae A\h'-(\w'A'u*4/10)'E . \" corrections for vroff .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u' .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u' . \" for low resolution devices (crt and lpr) .if \n(.H>23 .if \n(.V>19 \ \{\ . ds : e . ds 8 ss . ds o a . ds d- d\h'-1'\(ga . ds D- D\h'-1'\(hy . ds th \o'bp' . ds Th \o'LP' . ds ae ae . ds Ae AE .\} .rm #[ #] #H #V #F C .\" ======================================================================== .\" .IX Title "Symbol 3" .TH Symbol 3 "2002-11-24" "perl v5.8.0" "Perl Programmers Reference Guide" .SH "NAME" Symbol \- manipulate Perl symbols and their names .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 1 \& use Symbol; .Ve .PP .Vb 4 \& $sym = gensym; \& open($sym, "filename"); \& $_ = <$sym>; \& # etc. .Ve .PP .Vb 1 \& ungensym $sym; # no effect .Ve .PP .Vb 2 \& # replace *FOO{IO} handle but not $FOO, %FOO, etc. \& *FOO = geniosym; .Ve .PP .Vb 7 \& print qualify("x"), "\en"; # "Test::x" \& print qualify("x", "FOO"), "\en" # "FOO::x" \& print qualify("BAR::x"), "\en"; # "BAR::x" \& print qualify("BAR::x", "FOO"), "\en"; # "BAR::x" \& print qualify("STDOUT", "FOO"), "\en"; # "main::STDOUT" (global) \& print qualify(\e*x), "\en"; # returns \e*x \& print qualify(\e*x, "FOO"), "\en"; # returns \e*x .Ve .PP .Vb 3 \& use strict refs; \& print { qualify_to_ref $fh } "foo!\en"; \& $ref = qualify_to_ref $name, $pkg; .Ve .PP .Vb 3 \& use Symbol qw(delete_package); \& delete_package('Foo::Bar'); \& print "deleted\en" unless exists $Foo::{'Bar::'}; .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" \&\f(CW\*(C`Symbol::gensym\*(C'\fR creates an anonymous glob and returns a reference to it. Such a glob reference can be used as a file or directory handle. .PP For backward compatibility with older implementations that didn't support anonymous globs, \f(CW\*(C`Symbol::ungensym\*(C'\fR is also provided. But it doesn't do anything. .PP \&\f(CW\*(C`Symbol::geniosym\*(C'\fR creates an anonymous \s-1IO\s0 handle. This can be assigned into an existing glob without affecting the non-IO portions of the glob. .PP \&\f(CW\*(C`Symbol::qualify\*(C'\fR turns unqualified symbol names into qualified variable names (e.g. \*(L"myvar\*(R" \-> \*(L"MyPackage::myvar\*(R"). If it is given a second parameter, \f(CW\*(C`qualify\*(C'\fR uses it as the default package; otherwise, it uses the package of its caller. Regardless, global variable names (e.g. \*(L"\s-1STDOUT\s0\*(R", \*(L"\s-1ENV\s0\*(R", \*(L"\s-1SIG\s0\*(R") are always qualified with \&\*(L"main::\*(R". .PP Qualification applies only to symbol names (strings). References are left unchanged under the assumption that they are glob references, which are qualified by their nature. .PP \&\f(CW\*(C`Symbol::qualify_to_ref\*(C'\fR is just like \f(CW\*(C`Symbol::qualify\*(C'\fR except that it returns a glob ref rather than a symbol name, so you can use the result even if \f(CW\*(C`use strict 'refs'\*(C'\fR is in effect. .PP \&\f(CW\*(C`Symbol::delete_package\*(C'\fR wipes out a whole package namespace. Note this routine is not exported by default\*(--you may want to import it explicitly.