--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-win32-2.6.1/lib/pipes.py Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,282 @@
+"""Conversion pipeline templates.
+
+The problem:
+------------
+
+Suppose you have some data that you want to convert to another format,
+such as from GIF image format to PPM image format. Maybe the
+conversion involves several steps (e.g. piping it through compress or
+uuencode). Some of the conversion steps may require that their input
+is a disk file, others may be able to read standard input; similar for
+their output. The input to the entire conversion may also be read
+from a disk file or from an open file, and similar for its output.
+
+The module lets you construct a pipeline template by sticking one or
+more conversion steps together. It will take care of creating and
+removing temporary files if they are necessary to hold intermediate
+data. You can then use the template to do conversions from many
+different sources to many different destinations. The temporary
+file names used are different each time the template is used.
+
+The templates are objects so you can create templates for many
+different conversion steps and store them in a dictionary, for
+instance.
+
+
+Directions:
+-----------
+
+To create a template:
+ t = Template()
+
+To add a conversion step to a template:
+ t.append(command, kind)
+where kind is a string of two characters: the first is '-' if the
+command reads its standard input or 'f' if it requires a file; the
+second likewise for the output. The command must be valid /bin/sh
+syntax. If input or output files are required, they are passed as
+$IN and $OUT; otherwise, it must be possible to use the command in
+a pipeline.
+
+To add a conversion step at the beginning:
+ t.prepend(command, kind)
+
+To convert a file to another file using a template:
+ sts = t.copy(infile, outfile)
+If infile or outfile are the empty string, standard input is read or
+standard output is written, respectively. The return value is the
+exit status of the conversion pipeline.
+
+To open a file for reading or writing through a conversion pipeline:
+ fp = t.open(file, mode)
+where mode is 'r' to read the file, or 'w' to write it -- just like
+for the built-in function open() or for os.popen().
+
+To create a new template object initialized to a given one:
+ t2 = t.clone()
+
+For an example, see the function test() at the end of the file.
+""" # '
+
+
+import re
+import os
+import tempfile
+import string
+
+__all__ = ["Template"]
+
+# Conversion step kinds
+
+FILEIN_FILEOUT = 'ff' # Must read & write real files
+STDIN_FILEOUT = '-f' # Must write a real file
+FILEIN_STDOUT = 'f-' # Must read a real file
+STDIN_STDOUT = '--' # Normal pipeline element
+SOURCE = '.-' # Must be first, writes stdout
+SINK = '-.' # Must be last, reads stdin
+
+stepkinds = [FILEIN_FILEOUT, STDIN_FILEOUT, FILEIN_STDOUT, STDIN_STDOUT, \
+ SOURCE, SINK]
+
+
+class Template:
+ """Class representing a pipeline template."""
+
+ def __init__(self):
+ """Template() returns a fresh pipeline template."""
+ self.debugging = 0
+ self.reset()
+
+ def __repr__(self):
+ """t.__repr__() implements repr(t)."""
+ return '<Template instance, steps=%r>' % (self.steps,)
+
+ def reset(self):
+ """t.reset() restores a pipeline template to its initial state."""
+ self.steps = []
+
+ def clone(self):
+ """t.clone() returns a new pipeline template with identical
+ initial state as the current one."""
+ t = Template()
+ t.steps = self.steps[:]
+ t.debugging = self.debugging
+ return t
+
+ def debug(self, flag):
+ """t.debug(flag) turns debugging on or off."""
+ self.debugging = flag
+
+ def append(self, cmd, kind):
+ """t.append(cmd, kind) adds a new step at the end."""
+ if type(cmd) is not type(''):
+ raise TypeError, \
+ 'Template.append: cmd must be a string'
+ if kind not in stepkinds:
+ raise ValueError, \
+ 'Template.append: bad kind %r' % (kind,)
+ if kind == SOURCE:
+ raise ValueError, \
+ 'Template.append: SOURCE can only be prepended'
+ if self.steps and self.steps[-1][1] == SINK:
+ raise ValueError, \
+ 'Template.append: already ends with SINK'
+ if kind[0] == 'f' and not re.search(r'\$IN\b', cmd):
+ raise ValueError, \
+ 'Template.append: missing $IN in cmd'
+ if kind[1] == 'f' and not re.search(r'\$OUT\b', cmd):
+ raise ValueError, \
+ 'Template.append: missing $OUT in cmd'
+ self.steps.append((cmd, kind))
+
+ def prepend(self, cmd, kind):
+ """t.prepend(cmd, kind) adds a new step at the front."""
+ if type(cmd) is not type(''):
+ raise TypeError, \
+ 'Template.prepend: cmd must be a string'
+ if kind not in stepkinds:
+ raise ValueError, \
+ 'Template.prepend: bad kind %r' % (kind,)
+ if kind == SINK:
+ raise ValueError, \
+ 'Template.prepend: SINK can only be appended'
+ if self.steps and self.steps[0][1] == SOURCE:
+ raise ValueError, \
+ 'Template.prepend: already begins with SOURCE'
+ if kind[0] == 'f' and not re.search(r'\$IN\b', cmd):
+ raise ValueError, \
+ 'Template.prepend: missing $IN in cmd'
+ if kind[1] == 'f' and not re.search(r'\$OUT\b', cmd):
+ raise ValueError, \
+ 'Template.prepend: missing $OUT in cmd'
+ self.steps.insert(0, (cmd, kind))
+
+ def open(self, file, rw):
+ """t.open(file, rw) returns a pipe or file object open for
+ reading or writing; the file is the other end of the pipeline."""
+ if rw == 'r':
+ return self.open_r(file)
+ if rw == 'w':
+ return self.open_w(file)
+ raise ValueError, \
+ 'Template.open: rw must be \'r\' or \'w\', not %r' % (rw,)
+
+ def open_r(self, file):
+ """t.open_r(file) and t.open_w(file) implement
+ t.open(file, 'r') and t.open(file, 'w') respectively."""
+ if not self.steps:
+ return open(file, 'r')
+ if self.steps[-1][1] == SINK:
+ raise ValueError, \
+ 'Template.open_r: pipeline ends width SINK'
+ cmd = self.makepipeline(file, '')
+ return os.popen(cmd, 'r')
+
+ def open_w(self, file):
+ if not self.steps:
+ return open(file, 'w')
+ if self.steps[0][1] == SOURCE:
+ raise ValueError, \
+ 'Template.open_w: pipeline begins with SOURCE'
+ cmd = self.makepipeline('', file)
+ return os.popen(cmd, 'w')
+
+ def copy(self, infile, outfile):
+ return os.system(self.makepipeline(infile, outfile))
+
+ def makepipeline(self, infile, outfile):
+ cmd = makepipeline(infile, self.steps, outfile)
+ if self.debugging:
+ print cmd
+ cmd = 'set -x; ' + cmd
+ return cmd
+
+
+def makepipeline(infile, steps, outfile):
+ # Build a list with for each command:
+ # [input filename or '', command string, kind, output filename or '']
+
+ list = []
+ for cmd, kind in steps:
+ list.append(['', cmd, kind, ''])
+ #
+ # Make sure there is at least one step
+ #
+ if not list:
+ list.append(['', 'cat', '--', ''])
+ #
+ # Take care of the input and output ends
+ #
+ [cmd, kind] = list[0][1:3]
+ if kind[0] == 'f' and not infile:
+ list.insert(0, ['', 'cat', '--', ''])
+ list[0][0] = infile
+ #
+ [cmd, kind] = list[-1][1:3]
+ if kind[1] == 'f' and not outfile:
+ list.append(['', 'cat', '--', ''])
+ list[-1][-1] = outfile
+ #
+ # Invent temporary files to connect stages that need files
+ #
+ garbage = []
+ for i in range(1, len(list)):
+ lkind = list[i-1][2]
+ rkind = list[i][2]
+ if lkind[1] == 'f' or rkind[0] == 'f':
+ (fd, temp) = tempfile.mkstemp()
+ os.close(fd)
+ garbage.append(temp)
+ list[i-1][-1] = list[i][0] = temp
+ #
+ for item in list:
+ [inf, cmd, kind, outf] = item
+ if kind[1] == 'f':
+ cmd = 'OUT=' + quote(outf) + '; ' + cmd
+ if kind[0] == 'f':
+ cmd = 'IN=' + quote(inf) + '; ' + cmd
+ if kind[0] == '-' and inf:
+ cmd = cmd + ' <' + quote(inf)
+ if kind[1] == '-' and outf:
+ cmd = cmd + ' >' + quote(outf)
+ item[1] = cmd
+ #
+ cmdlist = list[0][1]
+ for item in list[1:]:
+ [cmd, kind] = item[1:3]
+ if item[0] == '':
+ if 'f' in kind:
+ cmd = '{ ' + cmd + '; }'
+ cmdlist = cmdlist + ' |\n' + cmd
+ else:
+ cmdlist = cmdlist + '\n' + cmd
+ #
+ if garbage:
+ rmcmd = 'rm -f'
+ for file in garbage:
+ rmcmd = rmcmd + ' ' + quote(file)
+ trapcmd = 'trap ' + quote(rmcmd + '; exit') + ' 1 2 3 13 14 15'
+ cmdlist = trapcmd + '\n' + cmdlist + '\n' + rmcmd
+ #
+ return cmdlist
+
+
+# Reliably quote a string as a single argument for /bin/sh
+
+_safechars = string.ascii_letters + string.digits + '!@%_-+=:,./' # Safe unquoted
+_funnychars = '"`$\\' # Unsafe inside "double quotes"
+
+def quote(file):
+ for c in file:
+ if c not in _safechars:
+ break
+ else:
+ return file
+ if '\'' not in file:
+ return '\'' + file + '\''
+ res = ''
+ for c in file:
+ if c in _funnychars:
+ c = '\\' + c
+ res = res + c
+ return '"' + res + '"'