Coverage for local/lib/python2.7/site-packages/sage/interfaces/cleaner.py : 30%

""" 

Interface to the Sage cleaner 

Triva Note: For the name "sage-cleaner", think of the 

"The Cleaner" from Pulp Fiction: 

http://www.frankjankowski.de/quiz/illus/keitel.jpg 

""" 

#***************************************************************************** 

# Copyright (C) 2007 William Stein <wstein@gmail.com> 

# 

# Distributed under the terms of the GNU General Public License (GPL) 

# as published by the Free Software Foundation; either version 2 of 

# the License, or (at your option) any later version. 

# http://www.gnu.org/licenses/ 

#***************************************************************************** 

import os 

from sage.misc.misc import SAGE_TMP 

def cleaner(pid, cmd=''): 

""" 

Write a line to the ``spawned_processes`` file with the given 

``pid`` and ``cmd``. 

""" 

if cmd != '': 

cmd = cmd.strip().split()[0] 

# This is safe, since only this process writes to this file. 

F = os.path.join(SAGE_TMP, 'spawned_processes') 

try: 

with open(F, 'a') as o: 

o.write('%s %s\n'%(pid, cmd)) 

except IOError: 

pass 

else: 

start_cleaner() 

def start_cleaner(): 

""" 

Start ``sage-cleaner`` in a new process group. 

""" 

if not os.fork(): 

os.setpgid(os.getpid(), os.getpid()) 

# Redirect stdin, stdout, stderr to /dev/null 

with open(os.devnull, "r+") as f: 

os.dup2(f.fileno(), 0) 

os.dup2(f.fileno(), 1) 

os.dup2(f.fileno(), 2) 

# Close all other file descriptors 

try: 

maxopenfiles = os.sysconf("SC_OPEN_MAX") 

if maxopenfiles <= 0: 

raise ValueError 

except ValueError: 

maxopenfiles = 1024 

os.closerange(3, maxopenfiles) 

os.execlp("sage-cleaner", "sage-cleaner")