源代码： Lib/pipes.py
The 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 /bin/sh command lines, a POSIX or compatible shell for os.system() and os.popen() 被要求。
An abstraction of a pipeline.
范例：
>>> import pipes >>> t = pipes.Template() >>> t.append('tr a-z A-Z', '--') >>> f = t.open('pipefile', 'w') >>> f.write('hello world') >>> f.close() >>> open('pipefile').read() 'HELLO WORLD'
Deprecated since version 2.7: Prior to Python 2.7, this function was not publicly documented. It is finally exposed publicly in Python 3.3 as the quote function in the shlex 模块。
Return a shell-escaped version of the string s . The returned value is a string that can safely be used as one token in a shell command line, for cases where you cannot use a list.
This idiom would be unsafe:
>>> filename = 'somefile; rm -rf ~' >>> command = 'ls -l {}'.format(filename) >>> print command # executed by a shell: boom! ls -l somefile; rm -rf ~
quote() lets you plug the security hole:
>>> command = 'ls -l {}'.format(quote(filename)) >>> print command ls -l 'somefile; rm -rf ~' >>> remote_command = 'ssh home {}'.format(quote(command)) >>> print remote_command ssh home 'ls -l '"'"'somefile; rm -rf ~'"'"''
The quoting is compatible with UNIX shells and with shlex.split() :
>>> remote_command = shlex.split(remote_command) >>> remote_command ['ssh', 'home', "ls -l 'somefile; rm -rf ~'"] >>> command = shlex.split(remote_command[-1]) >>> command ['ls', '-l', 'somefile; rm -rf ~']
Template objects following methods:
Restore a pipeline template to its initial state.
Return a new, equivalent, pipeline template.
若 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.
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.)
Add a new action at the beginning. See append() for explanations of the arguments.
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.
拷贝 infile to outfile through the pipe.
