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48 lines
1.7 KiB
TeX
48 lines
1.7 KiB
TeX
\section{\module{dbm} ---
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Simple ``database'' interface}
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\declaremodule{builtin}{dbm}
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\platform{Unix}
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\modulesynopsis{The standard ``database'' interface, based on ndbm.}
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The \module{dbm} module provides an interface to the \UNIX{}
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\code{(n)dbm} library. Dbm objects behave like mappings
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(dictionaries), except that keys and values are always strings.
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Printing a dbm object doesn't print the keys and values, and the
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\method{items()} and \method{values()} methods are not supported.
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See also the \refmodule{gdbm}\refbimodindex{gdbm} module, which
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provides a similar interface using the GNU GDBM library.
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The module defines the following constant and functions:
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\begin{excdesc}{error}
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Raised on dbm-specific errors, such as I/O errors.
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\exception{KeyError} is raised for general mapping errors like
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specifying an incorrect key.
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\end{excdesc}
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\begin{funcdesc}{open}{filename, \optional{flag, \optional{mode}}}
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Open a dbm database and return a dbm object. The \var{filename}
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argument is the name of the database file (without the \file{.dir} or
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\file{.pag} extensions).
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The optional \var{flag} argument can be
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\code{'r'} (to open an existing database for reading only --- default),
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\code{'w'} (to open an existing database for reading and writing),
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\code{'c'} (which creates the database if it doesn't exist), or
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\code{'n'} (which always creates a new empty database).
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The optional \var{mode} argument is the \UNIX{} mode of the file, used
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only when the database has to be created. It defaults to octal
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\code{0666}.
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\end{funcdesc}
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\begin{seealso}
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\seemodule{anydbm}{Generic interface to \code{dbm}-style databases.}
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\seemodule{whichdb}{Utility module used to determine the type of an
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existing database.}
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\end{seealso}
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