\section{\module{linecache} ---
         Treat files like lists of lines}

\declaremodule{standard}{linecache}
\sectionauthor{Moshe Zadka}{mzadka@geocities.com}
\modulesynopsis{This module treats files like random-access lists of lines.}


The \module{linecache} module allows one to get any line from any file,
while attempting to optimize internally, using a cache, the common case
where many lines are read from a file.

The \module{linecache} module defines the following functions:

\begin{funcdesc}{getline}{filename, lineno}
Get line \var{lineno} from file named \var{filename}. This function
will never throw an exception --- it will return \code{''} on errors.

If a file named \var{filename} is not found, the function will look
for it in the module search path.
\end{funcdesc}

\begin{funcdesc}{clearcache}{}
Clear the cache. You might want to use this function if you know that
you do not need to read lines from many of files you already read from
using this module.
\end{funcdesc}

\begin{funcdesc}{checkcache}{}
Check the cache is still valid. You might want to use this function if
you suspect that files you read from using this module might have
changed.
\end{funcdesc}

Example:

\begin{verbatim}
>>> import linecache
>>> linecache.getline('/etc/passwd', 4)
'sys:x:3:3:sys:/dev:/bin/sh\012'
\end{verbatim}