text: #!/usr/bin/env python
  """Script to commit the doc build outputs into the github-pages repo.
  
  Use:
  
    gh-pages.py [tag]
  
  If no tag is given, the current output of 'git describe' is used.  If given,
  that is how the resulting directory will be named.
  
  In practice, you should use either actual clean tags from a current build or
  something like 'current' as a stable URL for the most current version of the """
  
  #-----------------------------------------------------------------------------
  # Imports
  #-----------------------------------------------------------------------------
  import os
  import re
  import shutil
  import sys
  from os import chdir as cd
  from os.path import join as pjoin
  
  from subprocess import Popen, PIPE, CalledProcessError, check_call
  
  #-----------------------------------------------------------------------------
  # Globals
  #-----------------------------------------------------------------------------
  
  pages_dir = 'gh-pages'
  html_dir = 'build/html'
  pdf_dir = 'build/latex'
  pages_repo = 'git@github.com:ipython/ipython-doc.git'
  
  #-----------------------------------------------------------------------------
  # Functions
  #-----------------------------------------------------------------------------
  def sh(cmd):
      """Execute command in a subshell, return status code."""
      return check_call(cmd, shell=True)
  
  
  def sh2(cmd):
      """Execute command in a subshell, return stdout.
  
      Stderr is unbuffered from the subshell.x"""
      p = Popen(cmd, stdout=PIPE, shell=True)
      out = p.communicate()[0]
      retcode = p.returncode
      if retcode:
          raise CalledProcessError(retcode, cmd)
      else:
          return out.rstrip()
  
  
  def sh3(cmd):
      """Execute command in a subshell, return stdout, stderr
  
      If anything appears in stderr, print it out to sys.stderr"""
      p = Popen(cmd, stdout=PIPE, stderr=PIPE, shell=True)
      out, err = p.communicate()
      retcode = p.returncode
      if retcode:
          raise CalledProcessError(retcode, cmd)
      else:
          return out.rstrip(), err.rstrip()
  
  
  def init_repo(path):
      """clone the gh-pages repo if we haven't already."""
      sh("git clone %s %s"%(pages_repo, path))
      here = os.getcwdu()
      cd(path)
      sh('git checkout gh-pages')
      cd(here)
  
  #-----------------------------------------------------------------------------
  # Script starts
  #-----------------------------------------------------------------------------
  if __name__ == '__main__':
      # The tag can be given as a positional argument
      try:
          tag = sys.argv[1]
      except IndexError:
          try:
              tag = sh2('git describe --exact-match')
          except CalledProcessError:
              tag = "dev"   # Fallback
      
      startdir = os.getcwdu()
      if not os.path.exists(pages_dir):
          # init the repo
          init_repo(pages_dir)
      else:
          # ensure up-to-date before operating
          cd(pages_dir)
          sh('git checkout gh-pages')
          sh('git pull')
          cd(startdir)
  
      dest = pjoin(pages_dir, tag)
  
      # don't `make html` here, because gh-pages already depends on html in Makefile
      # sh('make html')
      if tag != 'dev':
          # only build pdf for non-dev targets
          sh2('make pdf')
  
      # This is pretty unforgiving: we unconditionally nuke the destination
      # directory, and then copy the html tree in there
      shutil.rmtree(dest, ignore_errors=True)
      shutil.copytree(html_dir, dest)
      if tag != 'dev':
          shutil.copy(pjoin(pdf_dir, 'ipython.pdf'), pjoin(dest, 'ipython.pdf'))
  
      try:
          cd(pages_dir)
          status = sh2('git status | head -1')
          branch = re.match('\# On branch (.*)$', status).group(1)
          if branch != 'gh-pages':
              e = 'On %r, git branch is %r, MUST be "gh-pages"' % (pages_dir,
                                                                   branch)
              raise RuntimeError(e)
  
          sh('git add -A %s' % tag)
          sh('git commit -m"Updated doc release: %s"' % tag)
          print
          print 'Most recent 3 commits:'
          sys.stdout.flush()
          sh('git --no-pager log --oneline HEAD~3..')
      finally:
          cd(startdir)
  
      print
      print 'Now verify the build in: %r' % dest
      print "If everything looks good, 'git push'"
  