"""Temporary files and filenames."""
# XXX This tries to be not UNIX specific, but I don't know beans about
# how to choose a temp directory or filename on MS-DOS or other
# systems so it may have to be changed...
import os
# Parameters that the caller may set to override the defaults
tempdir = None
template = None
def gettempdir():
"""Function to calculate the directory to use."""
global tempdir
if tempdir is not None:
return tempdir
try:
pwd = os.getcwd()
except (AttributeError, os.error):
pwd = os.curdir
attempdirs = ['/usr/tmp', '/tmp', pwd]
if os.name == 'nt':
attempdirs.insert(0, 'C:\\TEMP')
attempdirs.insert(0, '\\TEMP')
elif os.name == 'mac':
import macfs, MACFS
try:
refnum, dirid = macfs.FindFolder(MACFS.kOnSystemDisk,
MACFS.kTemporaryFolderType, 1)
dirname = macfs.FSSpec((refnum, dirid, '')).as_pathname()
attempdirs.insert(0, dirname)
except macfs.error:
pass
for envname in 'TMPDIR', 'TEMP', 'TMP':
if os.environ.has_key(envname):
attempdirs.insert(0, os.environ[envname])
testfile = gettempprefix() + 'test'
for dir in attempdirs:
try:
filename = os.path.join(dir, testfile)
fp = open(filename, 'w')
fp.write('blat')
fp.close()
os.unlink(filename)
tempdir = dir
break
except IOError:
pass
if tempdir is None:
msg = "Can't find a usable temporary directory amongst " + `attempdirs`
raise IOError, msg
return tempdir
_pid = None
def gettempprefix():
"""Function to calculate a prefix of the filename to use."""
global template, _pid
if os.name == 'posix' and _pid and _pid != os.getpid():
# Our pid changed; we must have forked -- zap the template
template = None
if template is None:
if os.name == 'posix':
_pid = os.getpid()
template = '@' + `_pid` + '.'
elif os.name == 'nt':
template = '~' + `os.getpid()` + '-'
elif os.name == 'mac':
template = 'Python-Tmp-'
else:
template = 'tmp' # XXX might choose a better one
return template
# Counter for generating unique names
counter = 0
def mktemp(suffix=""):
"""User-callable function to return a unique temporary file name."""
global counter
dir = gettempdir()
pre = gettempprefix()
while 1:
counter = counter + 1
file = os.path.join(dir, pre + `counter` + suffix)
if not os.path.exists(file):
return file
class TemporaryFileWrapper:
"""Temporary file wrapper
This class provides a wrapper around files opened for temporary use.
In particular, it seeks to automatically remove the file when it is
no longer needed.
"""
def __init__(self, file, path):
self.file = file
self.path = path
def close(self):
self.file.close()
os.unlink(self.path)
def __del__(self):
try: self.close()
except: pass
def __getattr__(self, name):
file = self.__dict__['file']
a = getattr(file, name)
if type(a) != type(0):
setattr(self, name, a)
return a
def TemporaryFile(mode='w+b', bufsize=-1, suffix=""):
"""Create and return a temporary file (opened read-write by default)."""
name = mktemp(suffix)
if os.name == 'posix':
# Unix -- be very careful
fd = os.open(name, os.O_RDWR|os.O_CREAT|os.O_EXCL, 0700)
try:
os.unlink(name)
return os.fdopen(fd, mode, bufsize)
except:
os.close(fd)
raise
else:
# Non-unix -- can't unlink file that's still open, use wrapper
file = open(name, mode, bufsize)
return TemporaryFileWrapper(file, name)
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