Perl 5 version 14.2 documentation
- BUGS AND WARNINGS
SDBM_File - Tied access to sdbm files
establishes a connection between a Perl hash variable and
a file in SDBM_File format;. You can manipulate the data in the file
just as if it were in a Perl hash, but when your program exits, the
data will remain in the file, to be used the next time your program
The hash variable you want to tie.
"SDBM_File". (Ths tells Perl to use the
SDBM_Filepackage to perform the functions of the hash.)
The name of the file you want to tie to the hash.
Flags. Use one of:
Read-only access to the data in the file.
Write-only access to the data in the file.
Both read and write access.
If you want to create the file if it does not exist, add
O_CREATto any of these, as in the example. If you omit
O_CREATand the file does not already exist, the
tiecall will fail.
The default permissions to use if a new file is created. The actual permissions will be modified by the user's umask, so you should probably use 0666 here. (See umask.)
On failure, the
tie call returns an undefined value and probably
to contain the reason the file could not be tied.
sdbm store returned -1, errno 22, key "..." at ...
This warning is emitted when you try to store a key or a value that is too long. It means that the change was not recorded in the database. See BUGS AND WARNINGS below.
BUGS AND WARNINGS
There are a number of limits on the size of the data that you can store in the SDBM file. The most important is that the length of a key, plus the length of its associated value, may not exceed 1008 bytes.