GDBM_File(3perl) Perl Programmers Reference Guide GDBM_File(3perl)NAME
GDBM_File - Perl5 access to the gdbm library.
SYNOPSIS
use GDBM_File ;
tie %hash, 'GDBM_File', $filename, &GDBM_WRCREAT, 0640;
# Use the %hash array.
untie %hash ;
DESCRIPTION
GDBM_File is a module which allows Perl programs to make use of the facilities provided by the GNU gdbm library. If you intend to use this
module you should really have a copy of the gdbm manualpage at hand.
Most of the libgdbm.a functions are available through the GDBM_File interface.
AVAILABILITY
gdbm is available from any GNU archive. The master site is "ftp.gnu.org", but you are strongly urged to use one of the many mirrors. You
can obtain a list of mirror sites from http://www.gnu.org/order/ftp.html.
BUGS
The available functions and the gdbm/perl interface need to be documented.
The GDBM error number and error message interface needs to be added.
SEE ALSO perl(1), DB_File(3), perldbmfilter.
perl v5.14.2 2011-09-19 GDBM_File(3perl)
Check Out this Related Man Page
AnyDBM_File(3pm) Perl Programmers Reference Guide AnyDBM_File(3pm)NAME
AnyDBM_File - provide framework for multiple DBMs
NDBM_File, DB_File, GDBM_File, SDBM_File, ODBM_File - various DBM implementations
SYNOPSIS
use AnyDBM_File;
DESCRIPTION
This module is a "pure virtual base class"--it has nothing of its own. It's just there to inherit from one of the various DBM packages.
It prefers ndbm for compatibility reasons with Perl 4, then Berkeley DB (See DB_File), GDBM, SDBM (which is always there--it comes with
Perl), and finally ODBM. This way old programs that used to use NDBM via dbmopen() can still do so, but new ones can reorder @ISA:
BEGIN { @AnyDBM_File::ISA = qw(DB_File GDBM_File NDBM_File) }
use AnyDBM_File;
Having multiple DBM implementations makes it trivial to copy database formats:
use Fcntl; 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;
DBM Comparisons
Here's a partial table of features the different packages offer:
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
[0] on mixed universe machines, may be in the bsd compat library, which is often shunned.
[1] Can be trimmed if you compile for one access method.
[2] See DB_File. Requires symbolic links.
[3] By default, but can be redefined.
SEE ALSO dbm(3), ndbm(3), DB_File(3), perldbmfilter
perl v5.18.2 2013-11-04 AnyDBM_File(3pm)