12 our @ISA = qw(Tie::Hash);
13 our $VERSION = "1.03";
15 XSLoader::load 'NDBM_File', $VERSION;
23 NDBM_File - Tied access to ndbm files
27 use Fcntl; # For O_RDWR, O_CREAT, etc.
30 # Now read and change the hash
31 $h{newkey} = newvalue;
39 C<NDBM_File> establishes a connection between a Perl hash variable and
40 a file in NDBM_File format;. You can manipulate the data in the file
41 just as if it were in a Perl hash, but when your program exits, the
42 data will remain in the file, to be used the next time your program
45 Use C<NDBM_File> with the Perl built-in C<tie> function to establish
46 the connection between the variable and the file. The arguments to
53 The hash variable you want to tie.
57 The string C<"NDBM_File">. (Ths tells Perl to use the C<NDBM_File>
58 package to perform the functions of the hash.)
62 The name of the file you want to tie to the hash.
72 Read-only access to the data in the file.
76 Write-only access to the data in the file.
80 Both read and write access.
84 If you want to create the file if it does not exist, add C<O_CREAT> to
85 any of these, as in the example. If you omit C<O_CREAT> and the file
86 does not already exist, the C<tie> call will fail.
90 The default permissions to use if a new file is created. The actual
91 permissions will be modified by the user's umask, so you should
92 probably use 0666 here. (See L<perlfunc/umask>.)
98 On failure, the C<tie> call returns an undefined value and probably
99 sets C<$!> to contain the reason the file could not be tied.
101 =head2 C<ndbm store returned -1, errno 22, key "..." at ...>
103 This warning is emmitted when you try to store a key or a value that
104 is too long. It means that the change was not recorded in the
105 database. See BUGS AND WARNINGS below.
107 =head1 BUGS AND WARNINGS
109 There are a number of limits on the size of the data that you can
110 store in the NDBM file. The most important is that the length of a
111 key, plus the length of its associated value, may not exceed 1008
114 See L<perlfunc/tie>, L<perldbmfilter>, L<Fcntl>