[Python-checkins] CVS: python/dist/src/Doc/lib libatexit.tex,NONE,1.1 libsys.tex,1.35,1.36 lib.tex,1.152,1.153

[Fred L. Drake]

Update of /cvsroot/python/python/dist/src/Doc/lib
In directory slayer.i.sourceforge.net:/tmp/cvs-serv8272/Doc/lib

Modified Files:
	libsys.tex lib.tex 
Added Files:
	libatexit.tex 
Log Message:

Added the atexit module and documentation from Skip Montanaro
<skip@mojam.com>.  Revisions to the markup to make it pass LaTeX, added
an index entry and a reference from the sys.exitfunc documentation.

This closes SourceForge patch #100620.


--- NEW FILE ---
\section{\module{atexit} ---
         exit handlers}

\declaremodule{standard}{atexit}
\moduleauthor{Skip Montanaro}{skip@mojam.com}
\sectionauthor{Skip Montanaro}{skip@mojam.com}
\modulesynopsis{Register and execute cleanup functions.}

The \module{atexit} module defines a single function to register
cleanup functions.  Functions thus registered are automatically
executed upon normal interpreter termination.

Note: the functions registered via this module are not called when the program is killed by a
signal, when a Python fatal internal error is detected, or when
\code{os._exit()} is called.

This is an alternate interface to the functionality provided by the
\code{sys.exitfunc} variable.
\withsubitem{(in sys)}{\ttindex{exitfunc}}

\begin{funcdesc}{register}{func\optional{, *args\optional{, **kargs}}}
Register \var{func} as a function to be executed at termination.  Any
optional arguments that are to be passed to \var{func} must be passed
as arguments to \function{register()}.

At normal program termination (for instance, if
\function{sys.exit()} is called or the main module's execution
completes), all functions registered are called in last in, first out
order.  The assumption is that lower level modules will normally be
imported before higher level modules and thus must be cleaned up
later.
\end{funcdesc}


\subsection{\module{atexit} Example \label{atexit-example}}

The following simple example demonstrates how a module can initialize
a counter from a file when it is imported and save the counter's
updated value automatically when the program terminates without
relying on the application making an explicit call into this module at
termination.

\begin{verbatim}
try:
    _count = int(open("/tmp/counter").read())
except IOError:
    _count = 0

def incrcounter(n):
    global _count
    _count = _count + n

def savecounter():
    open("/tmp/counter", "w").write("%d" % _count)

import atexit
atexit.register(savecounter)
\end{verbatim}


Index: libsys.tex
===================================================================
RCS file: /cvsroot/python/python/dist/src/Doc/lib/libsys.tex,v
retrieving revision 1.35
retrieving revision 1.36
diff -C2 -r1.35 -r1.36
*** libsys.tex	2000/04/13 17:51:58	1.35
--- libsys.tex	2000/06/28 15:07:30	1.36
***************
*** 128,132 ****
    the user (or by a program) to specify a clean-up action at program
    exit.  When set, it should be a parameterless function.  This function
!   will be called when the interpreter exits.  Note: the exit function
    is not called when the program is killed by a signal, when a Python
    fatal internal error is detected, or when \code{os._exit()} is called.
--- 128,134 ----
    the user (or by a program) to specify a clean-up action at program
    exit.  When set, it should be a parameterless function.  This function
!   will be called when the interpreter exits.  Only one function may be
!   installed in this way; to allow multiple functions which will be called
!   at termination, use the \refmodule{atexit} module.  Note: the exit function
    is not called when the program is killed by a signal, when a Python
    fatal internal error is detected, or when \code{os._exit()} is called.

Index: lib.tex
===================================================================
RCS file: /cvsroot/python/python/dist/src/Doc/lib/lib.tex,v
retrieving revision 1.152
retrieving revision 1.153
diff -C2 -r1.152 -r1.153
*** lib.tex	2000/06/13 20:51:29	1.152
--- lib.tex	2000/06/28 15:07:30	1.153
***************
*** 74,77 ****
--- 74,78 ----
  \input{libpython}		% Python Services
  \input{libsys}
+ \input{libatexit}
  \input{libtypes}
  \input{libuserdict}