diff -r ffa851df0825 -r 2fb8b9db1c86 symbian-qemu-0.9.1-12/python-2.6.1/Doc/library/pipes.rst --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/symbian-qemu-0.9.1-12/python-2.6.1/Doc/library/pipes.rst Fri Jul 31 15:01:17 2009 +0100 @@ -0,0 +1,92 @@ + +:mod:`pipes` --- Interface to shell pipelines +============================================= + +.. module:: pipes + :platform: Unix + :synopsis: A Python interface to Unix shell pipelines. +.. sectionauthor:: Moshe Zadka + + +The :mod:`pipes` module defines a class to abstract the concept of a *pipeline* +--- a sequence of converters from one file to another. + +Because the module uses :program:`/bin/sh` command lines, a POSIX or compatible +shell for :func:`os.system` and :func:`os.popen` is required. + +The :mod:`pipes` module defines the following class: + + +.. class:: Template() + + An abstraction of a pipeline. + +Example:: + + >>> import pipes + >>> t=pipes.Template() + >>> t.append('tr a-z A-Z', '--') + >>> f=t.open('/tmp/1', 'w') + >>> f.write('hello world') + >>> f.close() + >>> open('/tmp/1').read() + 'HELLO WORLD' + + +.. _template-objects: + +Template Objects +---------------- + +Template objects following methods: + + +.. method:: Template.reset() + + Restore a pipeline template to its initial state. + + +.. method:: Template.clone() + + Return a new, equivalent, pipeline template. + + +.. method:: Template.debug(flag) + + If *flag* is true, turn debugging on. Otherwise, turn debugging off. When + debugging is on, commands to be executed are printed, and the shell is given + ``set -x`` command to be more verbose. + + +.. method:: Template.append(cmd, kind) + + Append a new action at the end. The *cmd* variable must be a valid bourne shell + command. The *kind* variable consists of two letters. + + The first letter can be either of ``'-'`` (which means the command reads its + standard input), ``'f'`` (which means the commands reads a given file on the + command line) or ``'.'`` (which means the commands reads no input, and hence + must be first.) + + Similarly, the second letter can be either of ``'-'`` (which means the command + writes to standard output), ``'f'`` (which means the command writes a file on + the command line) or ``'.'`` (which means the command does not write anything, + and hence must be last.) + + +.. method:: Template.prepend(cmd, kind) + + Add a new action at the beginning. See :meth:`append` for explanations of the + arguments. + + +.. method:: Template.open(file, mode) + + Return a file-like object, open to *file*, but read from or written to by the + pipeline. Note that only one of ``'r'``, ``'w'`` may be given. + + +.. method:: Template.copy(infile, outfile) + + Copy *infile* to *outfile* through the pipe. +