.\" 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 "AnyDBM_File 3"
.TH AnyDBM_File 3 "2002-11-24" "perl v5.8.0" "Perl Programmers Reference Guide"
.SH "NAME"
AnyDBM_File \- provide framework for multiple DBMs
.PP
NDBM_File, DB_File, GDBM_File, SDBM_File, ODBM_File \- various DBM implementations
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\& use AnyDBM_File;
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
This module is a \*(L"pure virtual base class\*(R"\-\-it has nothing of its own.
It's just there to inherit from one of the various \s-1DBM\s0 packages. It
prefers ndbm for compatibility reasons with Perl 4, then Berkeley \s-1DB\s0 (See
DB_File), \s-1GDBM\s0, \s-1SDBM\s0 (which is always there\*(--it comes with Perl), and
finally \s-1ODBM\s0. This way old programs that used to use \s-1NDBM\s0 via \fIdbmopen()\fR
can still do so, but new ones can reorder \f(CW@ISA:\fR
.PP
.Vb 2
\& BEGIN { @AnyDBM_File::ISA = qw(DB_File GDBM_File NDBM_File) }
\& use AnyDBM_File;
.Ve
.PP
Having multiple \s-1DBM\s0 implementations makes it trivial to copy database formats:
.PP
.Vb 4
\& use POSIX; use NDBM_File; use DB_File;
\& tie %newhash, 'DB_File', $new_filename, O_CREAT|O_RDWR;
\& tie %oldhash, 'NDBM_File', $old_filename, 1, 0;
\& %newhash = %oldhash;
.Ve
.Sh "\s-1DBM\s0 Comparisons"
.IX Subsection "DBM Comparisons"
Here's a partial table of features the different packages offer:
.PP
.Vb 14
\& odbm ndbm sdbm gdbm bsd-db
\& ---- ---- ---- ---- ------
\& Linkage comes w/ perl yes yes yes yes yes
\& Src comes w/ perl no no yes no no
\& Comes w/ many unix os yes yes[0] no no no
\& Builds ok on !unix ? ? yes yes ?
\& Code Size ? ? small big big
\& Database Size ? ? small big? ok[1]
\& Speed ? ? slow ok fast
\& FTPable no no yes yes yes
\& Easy to build N/A N/A yes yes ok[2]
\& Size limits 1k 4k 1k[3] none none
\& Byte-order independent no no no no yes
\& Licensing restrictions ? ? no yes no
.Ve
.IP "[0]" 4
.IX Item "[0]"
on mixed universe machines, may be in the bsd compat library,
which is often shunned.
.IP "[1]" 4
.IX Item "[1]"
Can be trimmed if you compile for one access method.
.IP "[2]" 4
.IX Item "[2]"
See DB_File.
Requires symbolic links.
.IP "[3]" 4
.IX Item "[3]"
By default, but can be redefined.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fIdbm\fR\|(3), \fIndbm\fR\|(3), \fIDB_File\fR\|(3), perldbmfilter
|
